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Sample records for spectrometry canega measurements

  1. Spectrometry techniques for radioactivity measurements

    International Nuclear Information System (INIS)

    Anilkumar, S.

    2016-01-01

    The energy of the radiation emission following the nuclear decay is unique and the characteristic of the radio nuclide which undergoes decay. Thus measurement of the energy of the radiation offers a method of identifying the radio nuclides. The prime requirement of the energy measurement is a suitable detector which shows response proportional to the energy of the radiation rather than the presence of the radiation. The response from such detectors are suitably processed and distributed with respect to the signal strength which is proportional to incident energy. This distribution is normally referred as energy spectrum and is recorded in the multichannel analyser. The measurement of energy and intensity of radiation from the spectrum is called radiation spectrometry. Thus the radiation spectrometry allows the identification and quantification of radioactive isotopes in variety of matrices. The radiation spectrometry has now become a popular radioanalytical technique in wide area of nuclear fuel cycle programs. The popular spectrometry techniques commonly used for the radioactivity measurement and analysis are Alpha spectrometry, Gamma ray spectrometry and Beta spectrometry

  2. Deuterium measurement by emission spectrometry

    International Nuclear Information System (INIS)

    Niemann, E.G.; Heilig, K.; Dumke, I.

    1978-01-01

    The method makes it possible to determine the relative deuterium content of enriched water samples. For this, the relative intensities of the Hα and Dα lines are measured which are emitted by a high-frequency discharge in water vapour. Although the method is not as exact as mass spectrometry, it has the following advantages: - Easy sample preparation (no reduction necessary); - samples of highly different enrichment can be measured one after the other without the danger of memory effects; - much lower apparatus and cost expenditure. The necessary sample size is about the same in both methods. (orig.) [de

  3. Neutronic spectrometry measurements in sodium

    International Nuclear Information System (INIS)

    Perlini, G.; Acerbis, S.

    1987-01-01

    Measurements were made of neutronic penetration in sodium, which could serve as a reference and as a benchmark for computer codes. The model employed consisted of an assembly of 7 containers full of sodium for a total of 10 tons and a useful length of almost 4 metres. Measurements were performed at various depths along the central axis of the structure with proton recoil proportional counters. The energy band explored was between 100 and 650 keV. Here we report not only the original spectra of the impulses but also the neutronic spectra found by unfolding with the SPEC-4 code

  4. Neutron spectrometry measurements in iron

    International Nuclear Information System (INIS)

    Perlini, G.; Acerbis, S.; Carter, M.

    1988-01-01

    A compact structure was prepared for use in making measurements of neutron penetration in iron which could serve as reference data and as a check for computer codes. About 30 iron plates were put together giving a useful overall length of 130 cm. At various depths along the central axis of the iron block, measurements were made with liquid scintillator spectrometers and proton recoil proportional counters. The energy band explored was between 14 KeV and 10 MeV. Here we report the original spectra of the impulses and the neutron spectra found by the NE213 code based on the differential method and by unfolding with the SPEC4 code for liquid scintillation counters and proton recoil spectrometers, respectively. 12 figs., 60 tabs., 6 refs

  5. Burn-up measurements coupling gamma spectrometry and neutron measurement

    Energy Technology Data Exchange (ETDEWEB)

    Toubon, H.; Pin, P. [AREVA/CANBERRA, 1 rue des Herons, 78182 St Quentin-en-Yvelines Cedex (France); Lebrun, A. [IAEA, Wagramer Strasse 5, PO Box 100, Vienna (Austria); Oriol, L.; Saurel, N. [CEA Cadarache, 13108 Saint Paul Lez Durance Cedex (France); Gain, T. [AREVA/COGEMA Reprocessing Business Unit, La Hague, 50444 Beaumont Hague Cedex (France)

    2006-07-01

    The need to apply for burn-up credit arises with the increase of the initial enrichment of nuclear fuel. When burn-up credit is used in criticality safety studies, it is often necessary to confirm it by measurement. For the last 10 years, CANBERRA has manufactured the PYTHON system for such measurements. However, the method used in the PYTHON itself uses certain reactor data to arrive at burn-up estimates. Based on R and D led by CEA and COGEMA in the framework of burn-up measurement for burn-up credit and safeguards applications, CANBERRA is developing the next generation of burn-up measurement device. This new product, named SMOPY, is able to measure burn-up of any kind of irradiated fuel assembly with a combination of gamma spectrometry and passive neutron measurements. The measurement data is used as input to the CESAR depletion code, which has been developed and qualified by CEA and COGEMA for burn-up credit determinations. In this paper, we explain the complementary nature of the gamma and neutron measurements. In addition, we draw on our previous experience from PYTHON system and from COGEMA La Hague to show what types of evaluations are required to qualify the SMOPY system, to estimate its uncertainties, and to detect discrepancies in the fuel data given by the reactor plant to characterize the irradiated fuel assembly. (authors)

  6. Burn-up measurements coupling gamma spectrometry and neutron measurement

    International Nuclear Information System (INIS)

    Toubon, H.; Pin, P.; Lebrun, A.; Oriol, L.; Saurel, N.; Gain, T.

    2006-01-01

    The need to apply for burn-up credit arises with the increase of the initial enrichment of nuclear fuel. When burn-up credit is used in criticality safety studies, it is often necessary to confirm it by measurement. For the last 10 years, CANBERRA has manufactured the PYTHON system for such measurements. However, the method used in the PYTHON itself uses certain reactor data to arrive at burn-up estimates. Based on R and D led by CEA and COGEMA in the framework of burn-up measurement for burn-up credit and safeguards applications, CANBERRA is developing the next generation of burn-up measurement device. This new product, named SMOPY, is able to measure burn-up of any kind of irradiated fuel assembly with a combination of gamma spectrometry and passive neutron measurements. The measurement data is used as input to the CESAR depletion code, which has been developed and qualified by CEA and COGEMA for burn-up credit determinations. In this paper, we explain the complementary nature of the gamma and neutron measurements. In addition, we draw on our previous experience from PYTHON system and from COGEMA La Hague to show what types of evaluations are required to qualify the SMOPY system, to estimate its uncertainties, and to detect discrepancies in the fuel data given by the reactor plant to characterize the irradiated fuel assembly. (authors)

  7. OBT measurement of vegetation by mass spectrometry and radiometry

    International Nuclear Information System (INIS)

    Tamari, T.; Kakiuchi, H.; Momoshima, N.; Sugihara, S.; Baglan, N.; Uda, T.

    2011-01-01

    We carried out OBT (organically bound tritium) measurement by two different methods those are radiometry and mass spectrometry and compared the applicability of these methods for environmental tritium analysis. The dried grass sample was used for the experiments. To eliminate the exchangeable OBT, the sample was washed with tritium free water before analysis. Three times washing reduced the tritium activity in the labile sites below the detectable level. In radiometry the sample was combusted to convert the OBT as well as other hydrogen isotopes to. water and tritium activity in the water was measured by liquid scintillation counting (LSC). In mass spectrometry, the sample was kept in a glass container and 3 He produced by tritium decay was measured by mass spectrometry. The results were in good agreement suggesting applicability of these methods for environmental tritium analysis. The mass spectrometry is more suitable for environmental tritium research because of a lower detection limit than that of the LSC. (authors)

  8. The combined measurement of uranium by alpha spectrometry and secondary ion mass spectrometry (SIMS)

    International Nuclear Information System (INIS)

    Harvan, D.

    2009-01-01

    The aim of thesis was to found the dependence between radiometric method - alpha spectrometry and surface sensitive method - Secondary Ion Mass Spectrometry (SIMS). Uranium or naturally occurring uranium isotopes were studied. Samples (high polished stainless steel discs) with uranium isotopes were prepared by electrodeposition. Samples were measured by alpha spectrometry after electrodeposition and treatment. It gives surface activities. Weights, as well as surface's weights of uranium isotopes were calculated from their activities, After alpha spectrometry samples were analyzed by TOF-SIMS IV instrument in International Laser Centre in Bratislava. By the SIMS analysis intensities of uranium-238 were obtained. The interpretation of SIMS intensities vs. surface activity, or surface's weights of uranium isotopes indicates the possibility to use SIMS in quantitative analysis of surface contamination by uranium isotopes, especially 238 U. (author)

  9. Concentration of Radon Progeny in Air by Alpha Spectrometry Measurement

    International Nuclear Information System (INIS)

    Acena, M. L.; Crespo, M. T.

    1989-01-01

    The concentration of radon progeny in air has been determined by alpha spectrometry measurement of 214 Po and 318 Po. A known volume of air was passed through a filter, then the alpha activity was directly measured on this filter. (Author) 15 refs

  10. Velocity-space sensitivity of neutron spectrometry measurements

    DEFF Research Database (Denmark)

    Jacobsen, Asger Schou; Salewski, Mirko; Eriksson, J.

    2015-01-01

    Neutron emission spectrometry (NES) measures the energies of neutrons produced in fusion reactions. Here we present velocity-space weight functions for NES and neutron yield measurements. Weight functions show the sensitivity as well as the accessible regions in velocity space for a given range...

  11. Fine gamma spectrometry and release measurements

    International Nuclear Information System (INIS)

    Bovard, P.; Philippot, J.Cl.

    1978-01-01

    The growing number of nuclear facilities and a stricter interpretation of the fundamentals of radiological protection create an ever greater need for more thorough knowledge of releases to the environment. The measurement of releases and effluents involves study of a fairly large mixture of radionuclides. The methods of processing and interpreting Ge(Li) spectra that are described prove highly effective whenever the spectral topology is complex. The data obtained on the composition of nuclide mixtures can be very useful in the event of disputes or litigation. The four stages of metrology involved are discussed, namely measurement, spectral processing, exact definition of transition energies, and final interpretation. Particular stress is placed on the originality of the energy calibration procedure, which avoids the use of an external standard and is based on nuclear equations relating the spectral line energies; very high line definition accuracy is obtained in this way (better than 100eV on average for all the spectral lines present). Some examples of the technique used are given but no details are presented of the conditions and quality of sampling, or the implications for radiological protection of their results. (author)

  12. Resonance ionization mass spectrometry system for measurement of environmental samples

    International Nuclear Information System (INIS)

    Pibida, L.; McMahon, C.A.; Noertershaeuser, W.; Bushaw, B.A.

    2002-01-01

    A resonance ionization mass spectrometry (RIMS) system has been developed at the National Institute of Standards and Technology (NIST) for sensitive and selective determination of radio-cesium in the environment. The overall efficiency was determined to be 4x10-7 with a combined (laser and mass spectrometer) selectivity of 108 for both 135Cs and 137Cs with respect to 133Cs. RIMS isotopic ratio measurements of 135Cs/ 137Cs were performed on a nuclear fuel burn-up sample and compared to measurements on a similar system at Pacific Northwest National Laboratory (PNNL) and to conventional thermal ionization mass spectrometry (TIMS). Results of preliminary RIMS investigations on a freshwater lake sediment sample are also discussed

  13. Cortisol production rates measured by liquid chromatography/mass spectrometry

    International Nuclear Information System (INIS)

    Esteban, N.V.; Yergey, A.L.

    1990-01-01

    Cortisol production rates (FPRs) in physiologic and pathologic states in humans have been investigated over the past 30 years. However, there has been conflicting evidence concerning the validity of the currently accepted value of FPRs in humans (12 to 15 mg/m2/d) as determined by radiotracer methodology. The present study reviews previous methods proposed for the measurement of FPRs in humans and discusses the applications of the first method for the direct determination of 24-hour plasma FPRs during continuous administration of a stable isotope, using a thermospray high-pressure liquid chromatography-mass spectrometry technique. The technique is fast, sensitive, and, unlike gas chromatography-mass spectrometry methods, does not require derivatization, allowing on-line detection and quantification of plasma cortisol after a simple extraction procedure. The results of determination of plasma FPRs by stable tracer/mass spectrometry are directly in units of mass/time and, unlike radiotracer methods, are independent of any determination of volume of distribution or cortisol concentration. Our methodology offers distinct advantages over radiotracer techniques in simplicity and reliability since only single measurements of isotope ratios are required. The technique was validated in adrenalectomized patients. Circadian variations in daily FRPs were observed in normal volunteers, and, to date, results suggest a lower FRP in normal children and adults than previously believed. 88 references

  14. Accelerator mass spectrometry for measurement of long-lived radioisotopes.

    Science.gov (United States)

    Elmore, D; Phillips, F M

    1987-05-01

    Particle accelerators, such as those built for research in nuclear physics, can also be used together with magnetic and electrostatic mass analyzers to measure rare isotopes at very low abundance ratios. All molecular ions can be eliminated when accelerated to energies of millions of electron volts. Some atomic isobars can be eliminated with the use of negative ions; others can be separated at high energies by measuring their rate of energy loss in a detector. The long-lived radioisotopes (10)Be, (14)C,(26)A1, 36Cl, and (129)1 can now be measured in small natural samples having isotopic abundances in the range 10(-12) to 10(- 5) and as few as 10(5) atoms. In the past few years, research applications of accelerator mass spectrometry have been concentrated in the earth sciences (climatology, cosmochemistry, environmental chemistry, geochronology, glaciology, hydrology, igneous petrogenesis, minerals exploration, sedimentology, and volcanology), in anthropology and archeology (radiocarbon dating), and in physics (searches for exotic particles and measurement of halflives). In addition, accelerator mass spectrometry may become an important tool for the materials and biological sciences.

  15. Measurement of inclusion size by laser ablation ICP mass spectrometry

    International Nuclear Information System (INIS)

    Karasev, Andrey V.; Suito, Hideaki

    2004-01-01

    By using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), the measurement of particle size has been made for one component oxide (Al 2 O 3 and MgO) and multicomponent oxide (12CaO·7Al 2 O 3 and CaO-Al 2 O 3 -MgO) located on surface of iron or glass sample. The method of particle size estimation by LA-ICP-MS has been developed coupled with a new method of making samples with particles. The size calibration lines for Al 2 O 3 , MgO and CaO particles have been obtained. The results of particle size measurement by LA-ICP-MS are compared with those by SEM and single-particle optical sensing (SPOS) methods. It was confirmed that LA-ICP-MS has the perspective to be used for the quick measurement of inclusion composition and size in metal and other materials. The size frequency distributions of Al 2 O 3 particles measured by LA-ICP-MS in iron samples with particles agree reasonably well with those by SEM and SPOS in the range of particle diameter from 2 to 20 μm. The size of Al 2 O 3 , MgO and complex oxide (12CaO·7Al 2 O 3 and CaO-Al 2 O 3 -MgO) particles measured by LA-ICP-MS is in good agreement with that by SEM in the range of particle diameter from 10 to 40 μm. (author)

  16. Ambient Ionization Mass Spectrometry Measurement of Aminotransferase Activity

    Science.gov (United States)

    Yan, Xin; Li, Xin; Zhang, Chengsen; Xu, Yang; Cooks, R. Graham

    2017-06-01

    A change in enzyme activity has been used as a clinical biomarker for diagnosis and is useful in evaluating patient prognosis. Current laboratory measurements of enzyme activity involve multi-step derivatization of the reaction products followed by quantitative analysis of these derivatives. This study simplified the reaction systems by using only the target enzymatic reaction and directly detecting its product. A protocol using paper spray mass spectrometry for identifying and quantifying the reaction product has been developed. Evaluation of the activity of aspartate aminotransferase (AST) was chosen as a proof-of-principle. The volume of sample needed is greatly reduced compared with the traditional method. Paper spray has a desalting effect that avoids sprayer clogging problems seen when examining serum samples by nanoESI. This very simple method does not require sample pretreatment and additional derivatization reactions, yet it gives high quality kinetic data, excellent limits of detection (60 ppb from serum), and coefficients of variation <10% in quantitation. [Figure not available: see fulltext.

  17. Measurements of uranium enrichment by four techniques of gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Tojo, Takao

    1983-12-01

    Measurements of uranium enrichment with the uses of the LMRI (France) UO 2 standards have been made by four techniques of gamma-ray spectrometry, in order to examine measurement characteristics of each technique. The following results were obtained by the three techniques based on the direct determination of the peak area of the 186-keV gamma-rays from 235 U, when the standard sample of 6.297 a/o was used for measuring enrichments ranging from 1.4 a/o to 9.6 a/o ; (i) In a LEPS HP Ge gamma-ray spectrometry, standard deviation of the measured enrichments from the certified ones was 1.4 %, (ii) in a Ge(Li) gamma-ray spectrometry, the standard deviation was 2.0 %, (iii) in a NaI(Tl) gamma-ray spectrometry, the standard deviation was 1.2 %. In the fourth technique, the method of multiple single-channel analyzers, enrichments of 1.4 - 9.6 a/o were measured in the standard deviation of 0.51 %, when the most suitable pairs of standard samples were used for each sample. A part of sources of systematic errors which were caused by each technique adopted was revealed throughout the measurements. And also, it was recognized that the LMRI's values of enrichment were certified precisely, and the UO 2 standards were very useful for enrichment measurements in the four techniques of gamma-ray spectrometry used here. (author)

  18. Radioactivity Measurement in the Detergent Products by Gamma Spectrometry

    International Nuclear Information System (INIS)

    Ksouri, Abir

    2009-01-01

    Our study focuses on the evaluation of the level of radioactivity in the detergents. We have determined the specific activities of gamma emitting radionuclides belonging to the natural families of uranium, thorium and potassium using gamma spectrometry. The activities of radionuclides ( 235 U, 238U , 226 Ra, 232 Th, 40K) and their descendants are below the minimum detectable activity for dishwasher products, soaps, bleaches and shampoos, whereas they are found to levels considered very low (between 0,2 and 13 Bq/kg on average) in the products washes linens. These values are always lower than those of raw materials, what is explained by the conservation of radioactive material throughout the manufacturing process. The effective dose due to external exposure estimated below the regulatory standard recommended (<1 mSv / year), allows us to show that detergent products are not contaminated by radioactivity, are healthy and do not have harmful radiological impact on the consumer.

  19. The first results of measurements in military hospital laboratory for gamma spectrometry analysis

    International Nuclear Information System (INIS)

    Jankovic, Lj.; Pantelic, G.; Misovic, M.

    1997-01-01

    In this paper we present the basic features of the equipment for gamma spectrometry analysis and the first measurements results of the 134 Cs and 137 Cs activities. Gamma spectrum is measured using HP GE Detector. The obtained results show low level activities of the 134 Cs and 137 Cs in the environment. (author)

  20. Measurements of H*(10) in reference neutron fields using Bonner sphere spectrometry and LET spectrometry

    CERN Document Server

    Golnik, N; Králik, M

    2002-01-01

    A Bonner sphere spectrometer and the REM-2 recombination chamber were used for inter-comparison measurements of the neutron component of ambient dose equivalent, H sub n *(10) in reference neutron fields. The sup 2 sup 4 sup 1 Am-Be and sup 2 sup 5 sup 2 Cf neutron sources were exposed either free-in-air or placed in iron or paraffin filters. The REM-2 recombination chamber was used as a LET spectrometer. The agreement of H sub n *(10) values measured with both the methods was within experimental uncertainties of few percent. The determined neutron spectra were used for calculations of the REM-2 chamber response to H*(10).

  1. Clinical review: improving the measurement of serum thyroglobulin with mass spectrometry.

    Science.gov (United States)

    Hoofnagle, Andrew N; Roth, Mara Y

    2013-04-01

    Serum thyroglobulin (Tg) measurements are central to the management of patients treated for differentiated thyroid carcinoma. For decades, Tg measurements have relied on methods that are subject to interference by commonly found substances in human serum and plasma, such as Tg autoantibodies. As a result, many patients need additional imaging studies to rule out cancer persistence or recurrence that could be avoided with more sensitive and specific testing methods. The aims of this review are to: 1) briefly review the interferences common to Tg immunoassays; 2) introduce readers to liquid chromatography-tandem mass spectrometry as a method for quantifying proteins in human serum/plasma; and 3) discuss the potential benefits and limitations of the method in the quantification of serum Tg. Mass spectrometric methods have traditionally lacked the sensitivity, robustness, and throughput to be useful clinical assays. These methods failed to meet the necessary clinical benchmarks due to the nature of the mass spectrometry workflow and instrumentation. Over the past few years, there have been major advances in reagents, automation, and instrumentation for the quantification of proteins using mass spectrometry. More recently, methods using mass spectrometry to detect and quantify Tg have been developed and are of sufficient quality to be used in the management of patients. Novel serum Tg assays that use mass spectrometry may avoid the issue of autoantibody interference and other problems with currently available immunoassays for Tg. Prospective studies are needed to fully understand the potential benefits of novel Tg assays to patients and care providers.

  2. Design of an automatic sample changer for the measurement of neutron flux by gamma spectrometry

    International Nuclear Information System (INIS)

    Gago, Javier; Bruna, Ruben; Baltuano, Oscar; Montoya, Eduardo; Descreaux, Killian

    2014-01-01

    This paper presents calculus, selection and components design for the construction of an automatic system in order to measure neutron flux in a working nuclear reactor by the gamma spectrometry technique using samples irradiated on the RP-10 nucleus. This system will perform the measurement of interchanging 100 samples in a programed and automatic way, reducing operation time by the user and obtaining more accurate measures. (authors).

  3. Measurement of gluconeogenesis using glucose fragments and mass spectrometry after ingestion of deuterium oxide

    NARCIS (Netherlands)

    Chacko, Shaji K.; Sunehag, Agneta L.; Sharma, Susan; Sauer, Pieter J. J.; Haymond, Morey W.

    We report a new method to measure the fraction of glucose derived from gluconeogenesis using gas chromatography-mass spectrometry and positive chemical ionization. After ingestion of deuterium oxide by subjects, glucose derived from gluconeogenesis is labeled with deuterium. Our calculations of

  4. Measurement of gluconeogenesis using glucose fragments and mass spectrometry after ingestion of deuterium oxide.

    Science.gov (United States)

    We report a new method to measure the fraction of glucose derived from gluconeogenesis using gas chromatography-mass spectrometry and positive chemical ionization. After ingestion of deuterium oxide by subjects, glucose derived from gluconeogenesis is labeled with deuterium. Our calculations of gluc...

  5. Measurement of low radioactivity in underground laboratories by means of many-dimensional spectrometry

    International Nuclear Information System (INIS)

    Niese, Siegfried

    2008-01-01

    In this contribution beside the possibilities for the measurements in underground laboratories also the application of the many-dimensional spectrometry is considered, under which coincidence, anticoincidence, and time-resolving spectrometric are to be understood. Very extensively the interaction of cosmic radiation with matter is considered

  6. Precise atomic mass measurements by deflection mass spectrometry

    CERN Document Server

    Barber, R C

    2003-01-01

    Since its inception nearly 90 years ago by J.J. Thomson, the precise determination of atomic masses by the classical technique of deflecting charged particles in electric and magnetic fields has provided a large body of data on naturally occurring nuclides. Currently, such measurements on stable nuclides have frequently achieved a precision of better than two parts in 10 sup 9 of the mass. A review of the technique, together with a brief summary of the important historical developments in the field of precise atomic mass measurements, will be given. The more recent contributions to this field by the deflection mass spectrometer at the University of Manitoba will be provided as illustrations of the culmination of the techniques used and the applications that have been studied. A brief comparison between this and newer techniques using Penning traps will be presented.

  7. Uranium measurement by airborne gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Grasty, R.L.

    1975-01-01

    In the airborne measurement of uranium, window type gamma-ray spectrometers are used and it is necessary to correct for scattered high energy radiation from thallium 208 in the thorium decay series. This radiation can be scattered in the crystal, in the ground, and in the air. A theory, analogous to the theory of radioactive decay, is developed; it can adequately explain the spectrum buildup in the uranium window for a point source of thorium oxide immersed to different depths in water and for a detector above the water. The theory is extended to predict the buildup as a function of altitude for detectors of different sizes and shows that errors in the airborne measurement of uranium can be significant if no allowance is made for radiation scattered in the ground and in the air

  8. Glucose and glycerol concentrations and their tracer enrichment measurements using liquid chromatography tandem mass spectrometry

    DEFF Research Database (Denmark)

    Bornø, Andreas; Foged, Lene; van Hall, Gerrit

    2014-01-01

    The present study describes a new liquid chromatography tandem mass spectrometry method for high-throughput quantification of glucose and glycerol in human plasma using stable isotopically labeled internal standards and is suitable for simultaneous measurements of glucose and glycerol enrichments...... of variation were 2.0% and 9.7%, respectively. After derivatization, plasma samples were stable for at least 14 days. In conclusion, we have developed and validated a novel, accurate, and sensitive high-throughput liquid chromatography tandem mass spectrometry method for simultaneous determination of glucose...

  9. Improved Bonner sphere neutron spectrometry measurements for the nuclear industry

    Science.gov (United States)

    Roberts, N. J.; Thomas, D. J.; Visser, T. P. P.

    2017-11-01

    A novel, two-stage approach has been developed for producing the a priori spectrum for Bonner sphere unfolding in a case where neutrons are produced by spontaneous fission and (α,n) reactions, e.g. in UF6. The code SOURCES 4C is first used to obtain the energy spectrum of the neutrons inside the material, which is then fed into a MCNP model of the entire geometry to derive the neutron spectrum at the location of the Bonner sphere. Using this as the a priori spectrum produces a much more detailed unfolded Bonner sphere spectrum retaining fine structure from the calculation that would not be present if a simple estimated spectrum had been used as the a priori spectrum. This is illustrated using a Bonner sphere measurement of the neutron energy spectrum produced by a 48Y cylinder of UF6. From the unfolded spectrum an estimate has been made of the neutron ambient dose equivalent, i.e. the quantity which a neutron survey instrument should measure. The difference in the ambient dose equivalent of the unfolded spectrum is over 10% when using the novel approach instead of using a simpler estimate consisting of a single high energy peak, 1/E continuum, and thermal peak.

  10. Validation of Am-241 measurement in ion chamber type smoke detector by using gamma spectrometry system

    International Nuclear Information System (INIS)

    Yii Mei Wo; Khairul Nizam Razali

    2005-01-01

    Smoke detectors are useful devices in modern days that able to save many lives. Even though, the use of ion chamber type smoke detector (usually contain Americium-241) was exempted in Malaysia, but the trading of this device was controlled by regulation, under the Atomic Energy Licensing Act (Act 304). The activity of the Am-241 can be measured by using the Gamma Spectrometry System since it was much easier, compared to Alpha Spectrometry System. To do so, the system was first need to be calibrated using the standard reference source to find the efficiency of the germanium detector. The method used for the measurement was first validated for several relevant parameters, which include specificity, precision (repeatability), bias (accuracy), linearity, working range, detection limit, robustness and ruggedness to ensure it was fit for the purpose. The measured Am-241 activity inside the smoke detector will be reported together with a reasonable expanded uncertainty arise from the measurement. (Author)

  11. In situ measurements in an immerged environment of ambient gamma radiation activity and associated spectrometry

    International Nuclear Information System (INIS)

    Metivier, J.

    1993-01-01

    A set of site measurement devices composed of an ictometer, an air ionization chamber and a gamma ray spectrometry chain was modified so that the type of measurements could be carried out in an immerged environment with the equipment lying on the sediments of the prospected area. The different detectors can be controlled-and the data stored in a portable and autonomous 'PC' microcomputer from a light craft

  12. Improvements on Low Level Activity Gamma Measurements and X-ray Spectrometry at the CEA-MADERE Measurement Platform

    OpenAIRE

    Sergeyeva Victoria; Domergue Christophe; Destouches Christophe; Girard Jean Michel; Philibert Hervé; Bonora Jonathan; Thiollay Nicolas; Lyoussi Abdallah

    2016-01-01

    The CEA MADERE platform (Measurement Applied to DosimEtry in REactors) is a part of the Instrumentation Sensors and Dosimetry Laboratory (LDCI). This facility is dedicated to the specific activity measurements of solid and radioactive samples using Gamma and X-ray spectrometry. MADERE is a high-performance facility devoted to neutron dosimetry for experimental programs performed in CEA and for the irradiation surveillance programmes of PWR vessels. The MADERE platform is engaged in a continuo...

  13. A Customizable Flow Injection System for Automated, High Throughput, and Time Sensitive Ion Mobility Spectrometry and Mass Spectrometry Measurements.

    Science.gov (United States)

    Orton, Daniel J; Tfaily, Malak M; Moore, Ronald J; LaMarche, Brian L; Zheng, Xueyun; Fillmore, Thomas L; Chu, Rosalie K; Weitz, Karl K; Monroe, Matthew E; Kelly, Ryan T; Smith, Richard D; Baker, Erin S

    2018-01-02

    To better understand disease conditions and environmental perturbations, multiomic studies combining proteomic, lipidomic, and metabolomic analyses are vastly increasing in popularity. In a multiomic study, a single sample is typically extracted in multiple ways, and various analyses are performed using different instruments, most often based upon mass spectrometry (MS). Thus, one sample becomes many measurements, making high throughput and reproducible evaluations a necessity. One way to address the numerous samples and varying instrumental conditions is to utilize a flow injection analysis (FIA) system for rapid sample injections. While some FIA systems have been created to address these challenges, many have limitations such as costly consumables, low pressure capabilities, limited pressure monitoring, and fixed flow rates. To address these limitations, we created an automated, customizable FIA system capable of operating at a range of flow rates (∼50 nL/min to 500 μL/min) to accommodate both low- and high-flow MS ionization sources. This system also functions at varying analytical throughputs from 24 to 1200 samples per day to enable different MS analysis approaches. Applications ranging from native protein analyses to molecular library construction were performed using the FIA system, and results showed a highly robust and reproducible platform capable of providing consistent performance over many days without carryover, as long as washing buffers specific to each molecular analysis were utilized.

  14. Determination of {sup 126}Sn half-life from ICP-MS and gamma spectrometry measurements

    Energy Technology Data Exchange (ETDEWEB)

    Bienvenu, P.; Arnal, N.; Comte, J. [CEA Cadarache DEN/DEC/SA3C/LARC, Paul Lez Durance (France); Ferreux, L.; Lepy, M.C.; Be, M.M. [CEA Saclay LIST LNE/LNHB, Gif sur Yvette (France); Andreoletti, G. [AREVA Cogema SL/UP2-800, Beaumont Hague (France)

    2009-07-01

    A new value of {sup 126}Sn half-life was determined by combination of inductively coupled plasma-mass spectrometry (ICP-MS) and gamma spectrometry measurements on purified sample solutions collected from nuclear fuel reprocessing. {sup 126}Sn was isolated through dissolution of fission product precipitates and liquid-liquid extraction with N-benzoyl-N-phenyl-hydroxylamine (BPHA). The abundance of {sup 126}Sn atoms together with the absence of interfering species in the analysed solutions made it possible to measure both mass concentration and nuclide activity with high precision and accuracy. This led to a {sup 126}Sn half-life value of 1.980 (57) x 10{sup 5} a. (orig.)

  15. Evaluation of precision in measurements of uranium isotope ratio by thermionic mass spectrometry

    International Nuclear Information System (INIS)

    Moraes, N.M.P. de; Rodrigues, C.

    1977-01-01

    The parameters which affect the precision and accuracy of uranium isotopic ratios measurements by thermionic mass spectrometry are discussed. A statistical designed program for the analysis of the internal and external variances are presented. It was done an application of this statistical methods, in order to get mass discrimination factor, and its standard mean deviation, by using some results already published for 235 U/ 238 U ratio in NBS uranium samples, and natural uranium [pt

  16. Methods of measurement of integral and differential linearity distortions of spectrometry sets

    International Nuclear Information System (INIS)

    Fuan, Jacques; Grimont, Bernard; Marin, Roland; Richard, Jean-Pierre

    1969-05-01

    The objective of this document is to describe different measurement methods, and more particularly to present a software for the processing of obtained results in order to avoid interpretation by the investigator. In a first part, the authors define the parameters of integral and differential linearity, outlines their importance in measurements performed by spectrometry, and describe the use of these parameters. In the second part, they propose various methods of measurement of these linearity parameters, report experimental applications of these methods and compare the obtained results

  17. Analytical Validation of Accelerator Mass Spectrometry for Pharmaceutical Development: the Measurement of Carbon-14 Isotope Ratio

    International Nuclear Information System (INIS)

    Keck, B.D.; Ognibene, T.; Vogel, J.S.

    2010-01-01

    Accelerator mass spectrometry (AMS) is an isotope based measurement technology that utilizes carbon-14 labeled compounds in the pharmaceutical development process to measure compounds at very low concentrations, empowers microdosing as an investigational tool, and extends the utility of 14 C labeled compounds to dramatically lower levels. It is a form of isotope ratio mass spectrometry that can provide either measurements of total compound equivalents or, when coupled to separation technology such as chromatography, quantitation of specific compounds. The properties of AMS as a measurement technique are investigated here, and the parameters of method validation are shown. AMS, independent of any separation technique to which it may be coupled, is shown to be accurate, linear, precise, and robust. As the sensitivity and universality of AMS is constantly being explored and expanded, this work underpins many areas of pharmaceutical development including drug metabolism as well as absorption, distribution and excretion of pharmaceutical compounds as a fundamental step in drug development. The validation parameters for pharmaceutical analyses were examined for the accelerator mass spectrometry measurement of 14 C/C ratio, independent of chemical separation procedures. The isotope ratio measurement was specific (owing to the 14 C label), stable across samples storage conditions for at least one year, linear over 4 orders of magnitude with an analytical range from one tenth Modern to at least 2000 Modern (instrument specific). Further, accuracy was excellent between 1 and 3 percent while precision expressed as coefficient of variation is between 1 and 6% determined primarily by radiocarbon content and the time spent analyzing a sample. Sensitivity, expressed as LOD and LLOQ was 1 and 10 attomoles of carbon-14 (which can be expressed as compound equivalents) and for a typical small molecule labeled at 10% incorporated with 14 C corresponds to 30 fg equivalents. AMS

  18. Continuous high-frequency dissolved O2/Ar measurements by equilibrator inlet mass spectrometry.

    Science.gov (United States)

    Cassar, Nicolas; Barnett, Bruce A; Bender, Michael L; Kaiser, Jan; Hamme, Roberta C; Tilbrook, Bronte

    2009-03-01

    The oxygen (O(2)) concentration in the surface ocean is influenced by biological and physical processes. With concurrent measurements of argon (Ar), which has similar solubility properties as oxygen, we can remove the physical contribution to O(2) supersaturation and determine the biological oxygen supersaturation. Biological O(2) supersaturation in the surface ocean reflects the net metabolic balance between photosynthesis and respiration, i.e., the net community productivity (NCP). We present a new method for continuous shipboard measurements of O(2)/Ar by equilibrator inlet mass spectrometry (EIMS). From these measurements and an appropriate gas exchange parametrization, NCP can be estimated at high spatial and temporal resolution. In the EIMS configuration, seawater from the ship's continuous intake flows through a cartridge enclosing a gas-permeable microporous membrane contactor. Gases in the headspace of the cartridge equilibrate with dissolved gases in the flowing seawater. A fused-silica capillary continuously samples headspace gases, and the O(2)/Ar ratio is measured by mass spectrometry. The ion current measurements on the mass spectrometer reflect the partial pressures of dissolved gases in the water flowing through the equilibrator. Calibration of the O(2)/Ar ion current ratio (32/40) is performed automatically every 2 h by sampling ambient air through a second capillary. A conceptual model demonstrates that the ratio of gases reaching the mass spectrometer is dependent on several parameters, such as the differences in molecular diffusivities and solubilities of the gases. Laboratory experiments and field observations performed by EIMS are discussed. We also present preliminary evidence that other gas measurements, such as N(2)/Ar and pCO(2) measurements, may potentially be performed with EIMS. Finally, we compare the characteristics of the EIMS with the previously described membrane inlet mass spectrometry (MIMS) approach.

  19. Analytical Validation of Accelerator Mass Spectrometry for Pharmaceutical Development: the Measurement of Carbon-14 Isotope Ratio.

    Energy Technology Data Exchange (ETDEWEB)

    Keck, B D; Ognibene, T; Vogel, J S

    2010-02-05

    Accelerator mass spectrometry (AMS) is an isotope based measurement technology that utilizes carbon-14 labeled compounds in the pharmaceutical development process to measure compounds at very low concentrations, empowers microdosing as an investigational tool, and extends the utility of {sup 14}C labeled compounds to dramatically lower levels. It is a form of isotope ratio mass spectrometry that can provide either measurements of total compound equivalents or, when coupled to separation technology such as chromatography, quantitation of specific compounds. The properties of AMS as a measurement technique are investigated here, and the parameters of method validation are shown. AMS, independent of any separation technique to which it may be coupled, is shown to be accurate, linear, precise, and robust. As the sensitivity and universality of AMS is constantly being explored and expanded, this work underpins many areas of pharmaceutical development including drug metabolism as well as absorption, distribution and excretion of pharmaceutical compounds as a fundamental step in drug development. The validation parameters for pharmaceutical analyses were examined for the accelerator mass spectrometry measurement of {sup 14}C/C ratio, independent of chemical separation procedures. The isotope ratio measurement was specific (owing to the {sup 14}C label), stable across samples storage conditions for at least one year, linear over 4 orders of magnitude with an analytical range from one tenth Modern to at least 2000 Modern (instrument specific). Further, accuracy was excellent between 1 and 3 percent while precision expressed as coefficient of variation is between 1 and 6% determined primarily by radiocarbon content and the time spent analyzing a sample. Sensitivity, expressed as LOD and LLOQ was 1 and 10 attomoles of carbon-14 (which can be expressed as compound equivalents) and for a typical small molecule labeled at 10% incorporated with {sup 14}C corresponds to 30 fg

  20. Comparative study of the gamma spectrometry method performance in different measurement geometries

    International Nuclear Information System (INIS)

    Diaconescu, C.; Ichim, C.; Bujoreanu, L.; Florea, I.

    2013-01-01

    This paper presents the results obtained by gamma spectrometry on aqueous liquid waste sample using different measurement geometries. A liquid waste sample with known gamma emitters content was measured in three different geometries in order to assess the influence of the geometry on the final results. To obtain low measurement errors, gamma spectrometer was calibrated using a calibration standard with the same physical and chemical characteristics as the sample to be measured. Since the calibration was performed with the source at contact with HPGe detector, the waste sample was also measured, for all the three geometries, at the detector contact. The influence of the measurement geometry on the results was evaluated by computing the relative errors. The measurements performed using three different geometries (250 ml plastic vial, Sarpagan box and 24 ml Tricarb vial) showed that all these geometries may be used to quantify the activity of gamma emitters in different type of radioactive waste. (authors)

  1. Aircraft gamma-ray spectrometry in snow-water equivalent measurement

    Energy Technology Data Exchange (ETDEWEB)

    Kuittinen, R; Vironmaeki, J

    1979-01-01

    During the winter periods of 1976 to 1977 and 1977 to 1978, the Hydrological Office at the National Boards of Waters and the Geological Survey of Finland carried out a joint study to evaluate usefulness of gamma-ray spectrometry in snowwater equivalent measurement. A multichannel gamma-ray spectrometry was fitted out in a DC-3 aircraft. Fourteen snow courses were operated using gravimetric method and gamma-ray method. The snow courses were located in southern Finland in forest, swamp and agricultural land. The results show that the gamma ray method can be considered suitable for use in Finnish conditions and the accuracy of the gamma-ray method is almost of the same magnitude of the accuracy of the gravimetric method.

  2. Electron attachment rate constant measurement by photoemission electron attachment ion mobility spectrometry (PE-EA-IMS)

    International Nuclear Information System (INIS)

    Su, Desheng; Niu, Wenqi; Liu, Sheng; Shen, Chengyin; Huang, Chaoqun; Wang, Hongmei; Jiang, Haihe; Chu, Yannan

    2012-01-01

    Photoemission electron attachment ion mobility spectrometry (PE-EA-IMS), with a source of photoelectrons induced by vacuum ultraviolet radiation on a metal surface, has been developed to study electron attachment reaction at atmospheric pressure using nitrogen as the buffer gas. Based on the negative ion mobility spectra, the rate constants for electron attachment to tetrachloromethane and chloroform were measured at ambient temperature as a function of the average electron energy in the range from 0.29 to 0.96 eV. The experimental results are in good agreement with the data reported in the literature. - Highlights: ► Photoemission electron attachment ion mobility spectrometry (PE-EA-IMS) was developed to study electron attachment reaction. ► The rate constants of electron attachment to CCl 4 and CHCl 3 were determined. ► The present experimental results are in good agreement with the previously reported data.

  3. Measurements of β or α emitter long lived radionuclides using inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Provitina, O.

    1993-01-01

    The measurement of long-lived radionuclides is highly important for characterizing nuclear wastes for their later storage. The main techniques for characterizing these isotopes are α spectrometry, β counting and γ spectrometry. The large period of these isotopes leads to low specific activity needing time consuming measurements in order to obtain significant signals. Moreover, the radiometric techniques are often limited by problems of interferences involving several steps of pretreatments. Among these steps, the specific extraction with crown ethers is highly selective for the separation of 99 Tc, 129 I and 135 Cs particularly. The radiometric techniques are here replaced by inductively coupled plasma mass spectroscopy (ICP-MS) the advantages of which are: few interferences, sensitivity which does not depend on the radiologic period as compared to radiochemistry. ICP-MS can then measure 237 Np in enriched uranium matrix and thereby reduce by a factor of 4 the sample pretreatment and the duration of the analysis usually performed by α spectrometry. Another technique, electrothermal vaporization (ETV), is consequently used. Crown ether extraction-ETV-ICP-MS is employed for measuring the long lived radionuclides 99 Tc and 129 I. The conditions of the extraction and the parameters of the ETV and the ICP-MS are studied and optimized. The methods optimized (extraction, electrothermal vaporization) are validated in the case of 99 Tc, in real samples. The spike method is required to quantify technetium, the quantification with calibration leading to bad results. The results obtained are in good agreement with the expected values. Extraction of technetium on anionic resin and its measurement by the spike method with pneumatic nebulization-ICP-MS is also performed on other samples. Measured values are also in agreement with expected values, but the method of extraction is more time consuming (half a day) than the extraction with crown ether (one hour). (author). 54 figs

  4. Radionuclides in man and his environment measured by accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Hellborg, Ragnar; Erlandsson, Bengt; Kiisk, Madis; Persson, Per; Skog, Goeran; Stenstroem, Kristina; Mattsson, Soeren; Leide-Svegborn, Sigrid; Olofsson, Mikael

    1999-01-01

    Accelerator mass spectrometry (AMS) is a highly sensitive analytical method for measuring very low concentrations of both radionuclides and stable nuclides. For radioanalytical purposes, the main advantages of AMS compared to conventional radiometric methods are the use of smaller samples (mg size) and shorter measuring times (less than one hour). In this report some current applications of the AMS technique at the Lund Pelletron accelerator are presented, in particular studies of 14 C-labeled pharmaceuticals used in clinical nuclear medicine and biomedical research

  5. Overview of gamma spectrometry measurement devices developed by ENVINET a.s

    International Nuclear Information System (INIS)

    Sidlova, V.; Slama, L.; Holecek, V.; Chaloupkova, H.

    2008-01-01

    This paper demonstrates the development and usage of the devices designed for non- destructive radiological characterization of radioactive waste. All ..systems are based on gamma-spectrometry and are divided into two categories - stable and mobile. Stable ones involve only measurement in fixed detector - package configuration. They are used for assessment of packaged waste, mainly in drums. Mobile ones are flexible and allow measurement of a wide range of objects from various positions and can be also transported to arbitrary location. The calibration of such systems is performed by means of appropriate software which allows computation of full-energy peak efficiency in various configurations. (authors)

  6. Measuring Thermodynamic Properties of Metals and Alloys With Knudsen Effusion Mass Spectrometry

    Science.gov (United States)

    Copland, Evan H.; Jacobson, Nathan S.

    2010-01-01

    This report reviews Knudsen effusion mass spectrometry (KEMS) as it relates to thermodynamic measurements of metals and alloys. First, general aspects are reviewed, with emphasis on the Knudsen-cell vapor source and molecular beam formation, and mass spectrometry issues germane to this type of instrument are discussed briefly. The relationship between the vapor pressure inside the effusion cell and the measured ion intensity is the key to KEMS and is derived in detail. Then common methods used to determine thermodynamic quantities with KEMS are discussed. Enthalpies of vaporization, the fundamental measurement, are determined from the variation of relative partial pressure with temperature using the second-law method or by calculating a free energy of formation and subtracting the entropy contribution using the third-law method. For single-cell KEMS instruments, measurements can be used to determine the partial Gibbs free energy if the sensitivity factor remains constant over multiple experiments. The ion-current ratio method and dimer-monomer method are also viable in some systems. For a multiple-cell KEMS instrument, activities are obtained by direct comparison with a suitable component reference state or a secondary standard. Internal checks for correct instrument operation and general procedural guidelines also are discussed. Finally, general comments are made about future directions in measuring alloy thermodynamics with KEMS.

  7. Improving mass measurement accuracy in mass spectrometry based proteomics by combining open source tools for chromatographic alignment and internal calibration.

    Science.gov (United States)

    Palmblad, Magnus; van der Burgt, Yuri E M; Dalebout, Hans; Derks, Rico J E; Schoenmaker, Bart; Deelder, André M

    2009-05-02

    Accurate mass determination enhances peptide identification in mass spectrometry based proteomics. We here describe the combination of two previously published open source software tools to improve mass measurement accuracy in Fourier transform ion cyclotron resonance mass spectrometry (FTICRMS). The first program, msalign, aligns one MS/MS dataset with one FTICRMS dataset. The second software, recal2, uses peptides identified from the MS/MS data for automated internal calibration of the FTICR spectra, resulting in sub-ppm mass measurement errors.

  8. Prompt gamma-ray spectrometry for measurement of B-10 concentration in brain tissue and blood

    International Nuclear Information System (INIS)

    Nakagawa, Yoshinobu; Kitamura, Katsuji; Kobayashi, Toru; Matsumoto, Keizo; Hatanaka, Hiroshi.

    1993-01-01

    Boron-10 (B-10) concentration in the brain tissue and blood was measured continuously for 24 hours after injection of the B-10 compound in live rabbits using prompt gamma-ray spectrometry. Following injection of B-10 compound (Na 2 B 12 H 11 SH, 50mg/kg) dissolved in physiological saline, B-10 concentration was continuously measured in the brain tissue. Intermittently the concentration of B-10 in blood and cerebro-spinal fluid (CSF) was also measured. In 10 minutes after the injection of B-10 compound, the level of B-10 concentration reached the peak of 400-500 ppm in blood and 20-30 ppm in the normal brain tissue. In 60 minutes the level of B-10 concentration rapidly decreased and then a gradual decline was observed. The value was 15-30 ppm at 3 hours after injection, 5-10 ppm at 6 hours and 2-5 ppm at 24 hours in the blood. The concentration in the brain tissue was 3-8 ppm at 3 hours, 2-5 ppm at 6 hours and below 1.5 ppm at 24 hours. B-10 concentration in cerebro-spinal fluid was below 1 ppm. B-10 concentration was also measured in the brain tumor and blood in the human cases at boron neutron capture therapy (BNCT). These data studied by prompt gamma-ray spectrometry are very important and useful to decide the irradiation time. (author)

  9. Practical aspects of the uncertainty and traceability of spectrochemical measurement results by electrothermal atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Duta, S.; Robouch, P.; Barbu, L.; Taylor, P.

    2007-01-01

    The determination of trace elements concentration in water by electrothermal atomic absorption spectrometry (ETAAS) is a common and well established technique in many chemical testing laboratories. However, the evaluation of measurement uncertainty results is not systematically implemented. The paper presents an easy step-by-step example leading to the evaluation of the combined standard uncertainty of copper determination in water using ETAAS. The major contributors to the overall measurement uncertainty are identified due to amount of copper in water sample that mainly depends on the absorbance measurements, due to certified reference material and due to auto-sampler volume measurements. The practical aspects how the traceability of copper concentration in water can be established and demonstrated are also pointed out

  10. Practical aspects of the uncertainty and traceability of spectrochemical measurement results by electrothermal atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Duta, S. [Institute for Reference Materials and Measurements, Joint Research Centre, European Commission, Retieseweg 111, B-2440 Geel (Belgium); National Institute of Metrology, 042122 Vitan Barzesti 11, sector 4 Bucharest (Romania)], E-mail: steluta.duta@inm.ro; Robouch, P. [Institute for Reference Materials and Measurements, Joint Research Centre, European Commission, Retieseweg 111, B-2440 Geel (Belgium)], E-mail: Piotr.Robouch@ec.europa.eu; Barbu, L. [Coca-Cola Entreprise, Analytical Department, Bucharest (Romania); Taylor, P. [Institute for Reference Materials and Measurements, Joint Research Centre, European Commission, Retieseweg 111, B-2440 Geel (Belgium)], E-mail: Philip.Taylor@ec.europa.eu

    2007-04-15

    The determination of trace elements concentration in water by electrothermal atomic absorption spectrometry (ETAAS) is a common and well established technique in many chemical testing laboratories. However, the evaluation of measurement uncertainty results is not systematically implemented. The paper presents an easy step-by-step example leading to the evaluation of the combined standard uncertainty of copper determination in water using ETAAS. The major contributors to the overall measurement uncertainty are identified due to amount of copper in water sample that mainly depends on the absorbance measurements, due to certified reference material and due to auto-sampler volume measurements. The practical aspects how the traceability of copper concentration in water can be established and demonstrated are also pointed out.

  11. Extinction efficiencies of coated absorbing aerosols measured by cavity ring down aerosol spectrometry

    Directory of Open Access Journals (Sweden)

    E. Segre

    2008-03-01

    Full Text Available In this study, we measure the extinction efficiency at 532 nm of absorbing aerosol particles coated with a non-absorbing solid and liquid organic shell with coating thickness varying between 5 and 100 nm using cavity ring down aerosol spectrometry. For this purpose, we use nigrosin, an organic black dye, as a model absorbing core and two non-absorbing organic substances as shells, glutaric acid (GA and Di-Ethyl-Hexyl-Sebacate (DEHS. The measured behavior of the coated particles is consistent with Mie calculations of core-shell particles. Errors between measured and calculated values for nigrosin coated with GA and DEHS are between 0.5% and 10.5% and between 0.5% and 9%, respectively. However, it is evident that the calculations are in better agreement with the measured results for thinner coatings. Possible reasons for these discrepancies are discussed.

  12. Evaluation of TASTEX task H: measurement of plutonium isotopic abundances by gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Gunnink, R.; Prindle, A.L.; Asakura, Y.; Masui, J.; Ishiguro, N.; Kawasaki, A.; Kataoka, S.

    1981-10-01

    This report describes a computer-based gamma spectrometer system that was developed for measuring isotopic and total plutonium concentrations in nitric acid solutions. The system was installed at the Tokai reprocessing plant where it is undergoing testing and evaluation as part of the Tokai Advanced Safeguards Exercise (TASTEX). Objectives of TASTEX Task H, High-Resolution Gamma Spectrometer for Plutonium Isotopic Analysis, the methods and equipment used, the installation and calibration of the system, and the measurements obtained from several reprocessing campaigns are discussed and described. In general, we find that measurements for gamma spectroscopy agree well with those of mass spectrometry and of other chemical analysis. The system measures both freshly processed plutonium from the product accountability tank and aged plutonium solutions from storage tanks. 14 figures, 15 tables

  13. Isotope-dilution mass spectrometry in the measurement of plutonium isotope half-lives

    International Nuclear Information System (INIS)

    Abernathey, R.M.; Marsh, S.F.

    1981-01-01

    Isotope-dilution mass spectrometry has been used at Los Alamos to measure the half-lives of 239 Pu, 240 Pu, and 241 Pu. The latter was determined by measuring the rate of decrease of the 241 Pu/ 242 Pu ratio in an appropriate isotopic mixture over a period of several years. The half-lives of the two lighter isotopes are too long to be determined in this manner. They were determined by measuring the rate of production of the uranium daughter relative to a known added 233 U spike. Experimental procedures were designed to control sources of error and to permit a detailed statistical treatment which included all known sources of error and accounted for all covariances. The uncertainties, at the 95% confidence level, associated with the measured half-lives were less than 0.4% for 241 Pu and less than 0.2% for 239 Pu and 240 Pu

  14. Measurements of sulfur compounds in CO2 by diode laser atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Franzke, J.; Stancu, D.G.; Niemax, K.

    2003-01-01

    Two simple methods for the analysis of the total concentration of sulfur in CO 2 by diode laser atomic absorption spectrometry of excited, metastable sulfur atoms in a direct current discharge are presented. In the first method, the CO 2 sample gas is mixed with the plasma gas (Ar or He) while the second is based on reproducible measurements of the sulfur released from the walls in a helium discharge after being deposited as a result of operating the discharge in pure CO 2 sample gas. The detection limits obtained satisfy the requirements for the control of sulfur compounds in CO 2 used in the food and beverage industry

  15. Thermodynamic measurement of aluminium phosphate by double Knudsen cell mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Nagai, Takashi, E-mail: nagait@iis.u-tokyo.ac.j [Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505 (Japan); Tanaka, Yusuke; Maeda, Masafumi [Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505 (Japan)

    2010-08-15

    The ion currents of gaseous phosphorus oxides in equilibrium with a mixture of Al{sub 2}O{sub 3}.P{sub 2}O{sub 5} and Al{sub 2}O{sub 3} at T = (1473 to 1573) K were measured by double Knudsen cell mass spectrometry. The Gibbs free energy changes of the following reactions estimated in comparison with the ion currents from a mixture of (MgO){sub 3}.P{sub 2}O{sub 5} and MgO are as follows: (table)

  16. Recent Developments in Trace, Ultratrace and Isotope Ratio Measurements in Inductively Coupled Plasma Mass Spectrometry

    International Nuclear Information System (INIS)

    Zahran, N. F.

    2004-01-01

    Inductively coupled plasma mass spectrometry (ICP-MS) and Laser Ablation (LA-ICP-MS) are recent techniques for trace, ultratrace and isotope ratio measurements. Main features of these techniques and their figure of merit and capabilities are discussed. An overview of ICP-MS instrument is presented in addition to its precision, accuracy and detection limits. Uses of ICP-MS in environmental monitoring in some cases for detection of some radio nuclides are presented. Two geological applications namely, zircon grains analysis and age dating of Rb-Sr method are presented. Zn elemental and isotopic analyses in blood and serum as a biological application is shown. (Author)

  17. Protein hydrogen exchange measured at single-residue resolution by electron transfer dissociation mass spectrometry

    DEFF Research Database (Denmark)

    Rand, Kasper D; Zehl, Martin; Jensen, Ole Nørregaard

    2009-01-01

    Because of unparalleled sensitivity and tolerance to protein size, mass spectrometry (MS) has become a popular method for measuring the solution hydrogen (1H/2H) exchange (HX) of biologically relevant protein states. While incorporated deuterium can be localized to different regions by pepsin....... The deuterium labeling pattern of beta2-microglobulin is retained in the gaseous fragment ions by employing mild declustering conditions for electrospray ionization. A recently developed model peptide is used to arrive at such ion source declustering conditions that prevent the occurrence of intramolecular gas...

  18. Optimization of measurement geometries used by the C.I.R. 'Gamma Spectrometry' working group

    International Nuclear Information System (INIS)

    Escarieux, M.

    1979-01-01

    The choice of measurement geometry is closely tied to the objective sought in gamma quantitative analysis which consists in identifying the radionuclides present in a sample and in determining the voluminal quantities. The too low efficiency of the detector and the levels of activity sought make it necessary to place the sample in contact with the casing of the detector and select a sample geometry suited to the measurement. In point of fact this choice is often determined by other criteria, availability of the container for example, and this leads the laboratories taking part in the 'Gamma Spectrometry' Working Group of the Comite d'Instrumentation de Radioprotection to adopt joint gamma measurement geometries [fr

  19. An improvement of isochronous mass spectrometry: Velocity measurements using two time-of-flight detectors

    International Nuclear Information System (INIS)

    Shuai, P.; Xu, X.; Zhang, Y.H.; Xu, H.S.; Litvinov, Yu. A.; Wang, M.

    2016-01-01

    Isochronous mass spectrometry (IMS) in storage rings is a powerful tool for mass measurements of exotic nuclei with very short half-lives down to several tens of microseconds, using a multicomponent secondary beam separated in-flight without cooling. However, the inevitable momentum spread of secondary ions limits the precision of nuclear masses determined by using IMS. Therefore, the momentum measurement in addition to the revolution period of stored ions is crucial to reduce the influence of the momentum spread on the standard deviation of the revolution period, which would lead to a much improved mass resolving power of IMS. One of the proposals to upgrade IMS is that the velocity of secondary ions could be directly measured by using two time-of-flight (double TOF) detectors installed in a straight section of a storage ring. In this paper, we outline the principle of IMS with double TOF detectors and the method to correct the momentum spread of stored ions.

  20. Correlation analysis of measurement result between accelerator mass spectrometry and gamma counter

    International Nuclear Information System (INIS)

    Minamimoto, Ryogo; Cheng, C.; Oka, Takashi; Inoue, Tomio; Hamabe, Yoshimi; Shimoda, Marika

    2010-01-01

    The guidelines for microdosing in clinical trials were published in Japan in 2008 following the guidelines of the European Medicines Agency and the Food and Drug Administration. They recommend utilizing accelerator mass spectrometry (AMS) and positron emission tomography as candidates for monitoring drug metabolites in preclinical studies. We correlate the two methods by measuring appropriately labeled tissue samples from various mouse organs using both AMS and gamma counter. First, we measured the 14 C background levels in mouse organs using the AMS system. We then clarified the relationship between AMS and gamma counter by simultaneously administering 14 C-2-fluoro-2-deoxyglucose ( 14 C-FDG) and 18 F-2-fluoro-2-deoxyglucose ( 18 F-FDG). Tissue distribution was examined after 30 min, 1 h, 2 h and 4 h using the AMS system for 14 C-FDG and gamma counter for 18 F-FDG. Background 14 C levels were subtracted from the data obtained with radiotracer administration. The background 14 C concentration differed with tissue type measured. Background 14 C concentration in mouse liver was higher than in other organs, and was approximately 1.5-fold that in blood. The correlation coefficient (r) of the measurements between AMS ( 14 C-FDG) and gamma counter ( 18 F-FDG) was high in both normal (0.99 in blood, 0.91 in brain, 0.61 in liver and 0.78 in kidney) and tumor-bearing mice (0.95 in blood and 0.99 in tumor). The clearance profile of 18 F-FDG was nearly identical to that of 14 C-FDG measured with AMS. Accelerator mass spectrometry analysis has an excellent correlation with biodistribution measurements using gamma counter. Our results suggest that the combination of AMS and positron emission tomography (PET) can act as a complementary approach to accelerate drug development. (author)

  1. Measurement of 233U/234U ratios in contaminated groundwater using alpha spectrometry

    International Nuclear Information System (INIS)

    Harrison, Jennifer J.; Payne, Timothy E.; Wilsher, Kerry L.; Thiruvoth, Sangeeth; Child, David P.; Johansen, Mathew P.; Hotchkis, Michael A.C.

    2016-01-01

    The uranium isotope 233 U is not usually observed in alpha spectra from environmental samples due to its low natural and fallout abundance. It may be present in samples from sites in the vicinity of nuclear operations such as reactors or fuel reprocessing facilities, radioactive waste disposal sites or sites affected by clandestine nuclear operations. On an alpha spectrum, the two most abundant alpha emissions of 233 U (4.784 MeV, 13.2%; and 4.824 MeV, 84.3%) will overlap with the 234 U doublet peak (4.722 MeV, 28.4%; and 4.775 MeV, 71.4%), if present, resulting in a combined 233+234 U multiplet. A technique for quantifying both 233 U and 234 U from alpha spectra was investigated. A series of groundwater samples were measured both by accelerator mass spectrometry (AMS) to determine 233 U/ 234 U atom and activity ratios and by alpha spectrometry in order to establish a reliable 233 U estimation technique using alpha spectra. The Genie™ 2000 Alpha Analysis and Interactive Peak Fitting (IPF) software packages were used and it was found that IPF with identification of three peaks ( 234 U minor, combined 234 U major and 233 U minor, and 233 U major) followed by interference correction on the combined peak and a weighted average activity calculation gave satisfactory agreement with the AMS data across the 233 U/ 234 U activity ratio range (0.1–20) and 233 U activity range (2–300 mBq) investigated. Correlation between the AMS 233 U and alpha spectrometry 233 U was r 2  = 0.996 (n = 10). - Highlights: • Describes a technique for deconvoluting the combined 233 U and 234 U multiplet in alpha spectra. • Enables 233 U and 234 U activities and 233 U/ 234 U ratios to be quantified without requiring additional analysis and measurement. • Applicable to an environmental matrix (groundwater) using standard alpha spectrometry counting equipment, operation and set-up.

  2. Urinary nickel: measurement of exposure by inductively coupled plasma argon emission spectrometry.

    Science.gov (United States)

    Koizumi, Chisato; Usuda, Kan; Hayashi, Satsuki; Dote, Tomotaro; Kono, Koichi

    2004-09-01

    Nickel is a rare earth metal and is widely used in modern industry. Its overexposure in human beings can provoke significant effects including lung, cardiovascular and kidney diseases. As an index of occupational exposure, urine is widely used for the monitoring of nickel concentration because it is a minimally invasive method. Recent studies have used atomic absorption spectrometry to measure nickel concentration. In this study, we introduced novel inductively coupled plasma argon emission spectrometry (ICPAES) which enables us to measure multiple elements simultaneously with smaller volume and with lower detection limits compared to conventional atomic absorption emission spectrometry, and we established the new measuring method by determining the appropriate wavelengths for nickel concentration. Furthermore, using the established new measuring method, we investigated the correlation between a single oral administration of nickel and urine elimination in rats. As a result, different concentrations of nickel standard solutions were measured by ICPAES, and among five specific wavelengths of nickel, 221.647 and 231.604 nm were chosen because they had the highest inclines of both signal to background ratio and emission intensity in simple linear regression analysis. Next, by using healthy human urine samples that had not been exposed to nickel, 231.604 nm was determined to be the most appropriate wavelength because it did not present abnormal intensity due to obstacle wavelength. Male Wistar rats received an oral administration of nickel ranging from 0.025 to 250 mg/kg, which is equivalent to 0.0015 - 15% of LD50, and during the following 24 h, urine samples were collected and the nickel concentration was measured by ICPAES. With a single oral administration of nickel, there was an increase in urine nickel concentration in a dose-dependent manner and the appropriate equation was developed. Acute renal failure was not observed in this dosage of oral nickel

  3. Simple circuit for precise measurement of live dead or clock time in gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Hammer, W.; Sterlinski, S.

    1976-01-01

    The basic design features and characteristics of circuit are described in the paper. The circuit coupled to a multichannel analyser (MCA) enables one of times: live(Tsub(iota)), dead (Tsub(d)) or clock(Tsub(c)) to be measured precisely. Second one is measured by a built-in timer of MCA. Having the Tsub(c)/Tsub(iota) ratio and utilizing suitable mathematical formulas one can make the corrections for both main effects (dead-time and pile-up) which yield counting losses in gamma-ray spectrometry at high and/or variable activities. Two examples of the dead-time and pile-up corrections by using the new circuit are presented in this paper. (author)

  4. Validation of Cs-137 measurement in food samples using gamma spectrometry system

    International Nuclear Information System (INIS)

    Yii Mei Wo; Kamarozaman Ishak

    2005-01-01

    Cs-137 was found to be one of major radionuclide contaminant present in foods consumed by human. In some countries, regulations required consumption foods moving in international trade to be scanned for caesium (Cs-134 and Cs-137) to ensure it does not exceeding the maximum permissible level. This is to ensure that the intake of such foods will not accumulate radionuclide until the significant level inside the human body. Gamma Spectrometry System was used to perform the measurement of caesium isotopes, because it was one of the easiest methods to be performed. This measuring method must be validated for several parameters include specificity, precision (repeatability), bias (accuracy), linearity, range, detection limit, robustness and ruggedness in order to ensure it is fit for the purpose. This paper would summarise how these parameters were fulfilled for this analytical method using several types certified reference materials. The same validated method would be considered workable on Cs-134 as well. (Author)

  5. Penetration of bomb radiocarbon in the tropical Indian Ocean measured by means of accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Bard, E.; Arnold, M.; Maurice, P.; Monfray, P.; Duplessy, J.C.; Oestlund, H.G.

    1988-01-01

    Radiocarbon measurements performed on seawater samples by means of accelerator mass spectrometry (AMS) enable to reduce by a factor of 2000 the water sample size needed for the 14 C measurements. Therefore no chemical treatment on board the oceanographic vessel is required. Seventy-four AMS 14 C determinations on samples collected in the tropical-equatorial Indian Ocean during the second leg of the INDIGO program (1986) are presented and compared with the β-counting results obtained during the same campaign and the GEOSECS program (1978). A pronounced reduction of the equatorial 14 C deficit suggests that substantial amounts of bomb- 14 C are associated with the westward flowing Pacific water which enters the Indian Ocean via passages through the Indonesia Archipelago and/or to meridional mixing with 14 C-rich water of the southern subtropical gyre. (orig.)

  6. Neutron spectrometry and dosimetry measurement at workplaces for calibration of individual PGP-DIN dosemeters

    International Nuclear Information System (INIS)

    Itie, C.; Muller, H.; Asselineau, B.; Medioni, R.; Crovisier, P.; Valier-Bradier, P.; Groetz, J.E.; Piot, J.

    2003-01-01

    Measurements to determine new coefficients for individual neutron dosimeters PGP-DIN complying with the ICRP 60 recommendations were performed at two workplaces at the CEA of Valduc: a storage room and a plutonium reprocessing plant. Two spectrometry campaigns were performed allowing a better assessment of doses received by operators working at these workplaces. Neutron energy fluence and ambient dose equivalent rate H * (10) distributions were measured as function of neutron energy by using the ROSPEC device and BONNER spheres spectrometer. The radiation field being mixed neutron and gamma, the gamma component was also evaluated: neutron and photon dose-rate meters were used to evaluate the ambient dose rate equivalent. Individual dosemeters were positioned on an ISO water slab phantom. In addition, calculations were performed using the MCNP simulation code for different configurations. (authors)

  7. Formaldehyde measurements by Proton transfer reaction – Mass Spectrometry (PTR-MS: correction for humidity effects

    Directory of Open Access Journals (Sweden)

    A. Vlasenko

    2010-08-01

    Full Text Available Formaldehyde measurements can provide useful information about photochemical activity in ambient air, given that HCHO is formed via numerous oxidation processes. Proton transfer reaction mass spectrometry (PTR-MS is an online technique that allows measurement of VOCs at the sub-ppbv level with good time resolution. PTR-MS quantification of HCHO is hampered by the humidity dependence of the instrument sensitivity, with higher humidity leading to loss of PTR-MS signal. In this study we present an analytical, first principles approach to correct the PTR-MS HCHO signal according to the concentration of water vapor in sampled air. The results of the correction are validated by comparison of the PTR-MS results to those from a Hantzsch fluorescence monitor which does not have the same humidity dependence. Results are presented for an intercomparison made during a field campaign in rural Ontario at Environment Canada's Centre for Atmospheric Research Experiments.

  8. Concentration of Uranium Radioisotopes in Albanian Drinking Waters Measured by Alpha Spectrometry

    Science.gov (United States)

    Bylyku, Elida; Cfarku, Florinda; Deda, Antoneta; Bode, Kozeta; Fishka, Kujtim

    2010-01-01

    Uranium is a radioactive material that is frequently found in rocks and soil. When uranium decays, it changes into different elements that are also radioactive, including radon, a gas that is known to cause a lung cancer. The main concern with uranium in drinking water is harm to the kidneys. Public water systems are required to keep uranium levels at or below 500 mBq per liter to protect against kidney damage. Such an interest is needed due to safety, regulatory compliance and disposal issue for uranium in the environment since uranium is included as an obligatory controlled radionuclide in the European Legislation (Directive 98/83 CE of Council of 03.11.1998). The aim of this work is to measure the levels of uranium in drinking and drilled well waters in Albania. At first each sample was measured for total Alpha and total Beta activity. The samples with the highest levels of total alpha activity were chosen for the determination of uranium radioisotopes by alpha spectrometry. A radiochemical procedure using extraction with TBP (Tri-Butyl-Phosphate) is used in the presence of U232 as a yield tracer. Thin sources for alpha spectrometry are prepared by electrodepositing on to stainless steel discs. The results of the U238 activity measured in the different samples, depending from their geological origin range between 0.55-13.87 mBq/l. All samples measured results under the European Directive limits for U238 (5-500 mBq/1), Dose Coefficients according to Directive 96/29 EURATOM.

  9. Measurement control for plutonium isotopic measurements using gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Fleissner, J.G.

    1985-01-01

    A measurement control (MC) program should be an integral part of every nondestructive assay measurement system used for the assay of special nuclear materials. This report describes an MC program for plutonium isotopic composition measurements using high-resolution gamma-ray spectroscopy. This MC program emphasizes the standardization of data collection procedures along with the implementation of internal and external measurement control checks to provide the requisite measurement quality assurance. This report also describes the implementation of the MC program in the isotopic analysis code GRPAUT. Recommendations are given concerning the importance and frequency of the various MC checks in order to ensure a successful implementation of the MC procedures for the user's application

  10. Activation measurements for fast neutrons. Part B. 63Ni measurements by accelerator mass spectrometry (AMS)

    International Nuclear Information System (INIS)

    Straume, Tore; Rugel, Georg; Marchetti, Alfredo A.

    2005-01-01

    The AMS-measurements of 63 Ni in copper samples obtained from different distances in Hiroshima represent the first detection of fast neutrons after more than 50 years, and the first reliable bomb-induced fast neutron measurements beyond 700 m from the hypocenter. A major significance of these 63 Ni results is that they provide, for the first time, fast neutron measurements at the distances most relevant to atomic-bomb survivor locations (900-1,500 m). The measurement of 63 Ni in copper samples using AMS provides a substantial improvement in fast neutron detection compared with the 32 P measurements made in 1945. For example, the measurement-to-background ratio at about 400 m from the hypocenter is about 55 for 63 Ni and only about 2 for the 32 P measurements. Also, the 63 Ni measurements reach background levels at about 1,800 m from the hypocenter compared with only about 700 m for 32 P. At distances of ∼1,800 m from the hypocenter, out to at least 5,000 meters, the measurements appear to level off at a value on the order of 7x10 4 atoms of 63 Ni/g of Cu, suggesting a background of approximately that magnitude. When this background is subtracted and the resulting data corrected to 1945, the measured 63 Ni in copper samples from Hiroshima are in good agreement with DS02 sample-specific calculations. Comparisons with DS86 calculations also show good agreement except at the Bank of Japan. The difference at that distance is significant when compared with DS86 calculations. (J.P.N.)

  11. Disjunct eddy covariance measurements of volatile organic compound fluxes using proton transfer reaction mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Taipale, R.

    2011-07-01

    Volatile organic compounds (VOCs) are emitted into the atmosphere from natural and anthropogenic sources, vegetation being the dominant source on a global scale. Some of these reactive compounds are deemed major contributors or inhibitors to aerosol particle formation and growth, thus making VOC measurements essential for current climate change research. This thesis discusses ecosystem scale VOC fluxes measured above a boreal Scots pine dominated forest in southern Finland. The flux measurements were performed using the micrometeorological disjunct eddy covariance (DEC) method combined with proton transfer reaction mass spectrometry (PTR-MS), which is an online technique for measuring VOC concentrations. The measurement, calibration, and calculation procedures developed in this work proved to be well suited to long-term VOC concentration and flux measurements with PTR-MS. A new averaging approach based on running averaged covariance functions improved the determination of the lag time between wind and concentration measurements, which is a common challenge in DEC when measuring fluxes near the detection limit. The ecosystem scale emissions of methanol, acetaldehyde, and acetone were substantial. These three oxygenated VOCs made up about half of the total emissions, with the rest comprised of monoterpenes. Contrary to the traditional assumption that monoterpene emissions from Scots pine originate mainly as evaporation from specialized storage pools, the DEC measurements indicated a significant contribution from de novo biosynthesis to the ecosystem scale monoterpene emissions. This thesis offers practical guidelines for long-term DEC measurements with PTR-MS. In particular, the new averaging approach to the lag time determination seems useful in the automation of DEC flux calculations. Seasonal variation in the monoterpene biosynthesis and the detailed structure of a revised hybrid algorithm, describing both de novo and pool emissions, should be determined in

  12. Data in support for the measurement of serum 25-hydroxyvitamin D (25OHD by tandem mass spectrometry

    Directory of Open Access Journals (Sweden)

    M.E. Jensen

    2016-09-01

    Full Text Available This article provides data and a method related to a research paper entitled “Assessing vitamin D nutritional status: is capillary blood adequate?” (Jensen et al., 2016 [1]. Circulating 25OHD, the accepted biomarker of the vitamin D nutritional status, is routinely measured by automated immunoassays, that although may be performed in hospital central laboratories, often suffer from a lack of specificity with regards to the different vitamin D metabolites, “Measurement of circulating 25-hydroxyvitamin D: a historical review” (Le Goff et al., 2015 [2]. Mass spectrometry offers this specificity. This article describes the performance of an in-house tandem mass spectrometry method for the individual measurement of 25OHD3, 25OHD2 and 3-épi-25OHD3. Keywords: Vitamin D, 25-hydroxyvitamin D, Mass spectrometry

  13. Mass spectrometry and immunoassay: how to measure steroid hormones today and tomorrow.

    Science.gov (United States)

    Taylor, Angela E; Keevil, Brian; Huhtaniemi, Ilpo T

    2015-08-01

    The recent onslaught of mass spectrometry (MS) to measurements of steroid hormones, including demands that they should be the only acceptable method, has confused clinicians and scientists who have relied for more than 40 years on a variety of immunoassay (IA) methods in steroid hormone measurements. There is little doubt that MS methods with their superior specificity will be the future method of choice in many clinical and research applications of steroid hormone measurement. However, the majority of steroid measurements are currently, and will continue to be, carried out using various types of IAs for several reasons, including their technical ease, cost and availability of commercial reagents. Speedy replacement of all IAs with MS is an unrealistic and unnecessary goal, because the availability of MS measurements is limited by cost, need of expensive equipment, technical demands and lack of commercial applications. Furthermore, IAs have multiple well-known advantages that vindicate their continuing use. The purpose of this article is to elucidate the advantages and limitations of the MS and IA techniques from two angles, i.e. promotion of MS and defence of IA. The purpose of the text is to give the reader an unbiased view about the current state and future trends of steroid analysis and to help him/her choose the correct assay method to serve his/her diagnostic and research needs. © 2015 European Society of Endocrinology.

  14. Gas-phase pesticide measurement using iodide ionization time-of-flight mass spectrometry

    Directory of Open Access Journals (Sweden)

    T. Murschell

    2017-06-01

    Full Text Available Volatilization and subsequent processing in the atmosphere are an important environmental pathway for the transport and chemical fate of pesticides. However, these processes remain a particularly poorly understood component of pesticide lifecycles due to analytical challenges in measuring pesticides in the atmosphere. Most pesticide measurements require long (hours to days sampling times coupled with offline analysis, inhibiting observation of meteorologically driven events or investigation of rapid oxidation chemistry. Here, we present chemical ionization time-of-flight mass spectrometry with iodide reagent ions as a fast and sensitive measurement of four current-use pesticides. These semi-volatile pesticides were calibrated with injections of solutions onto a filter and subsequently volatilized to generate gas-phase analytes. Trifluralin and atrazine are detected as iodide–molecule adducts, while permethrin and metolachlor are detected as adducts between iodide and fragments of the parent analyte molecule. Limits of detection (1 s are 0.37, 0.67, 0.56, and 1.1 µg m−3 for gas-phase trifluralin, metolachlor, atrazine, and permethrin, respectively. The sensitivities of trifluralin and metolachlor depend on relative humidity, changing as much as 70 and 59, respectively, as relative humidity of the sample air varies from 0 to 80 %. This measurement approach is thus appropriate for laboratory experiments and potentially near-source field measurements.

  15. "1"4C ages and calendar years of Japanese swords measured with accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Nagata, Kazuhiro; Matsubara, Akihiro; Kokubu, Yoko; Nakamura, Toshio

    2016-01-01

    Steel of Japanese swords has been produced with Tatara process from iron sand and charcoal. Carbon dissolved in steel was absorbed from wooden charcoal fuel during the production of the steel. From the decay of "1"4C activity in the steel, the "1"4C age of Japanese sword can be determined. The "1"4C ages of 4 Japanese swords were measured with accelerator mass spectrometry and calibrated to calendar years. Each "1"4C age provided plural calendar year periods with definite probabilities, and one of the periods agreed with the production year of each sword that was determined from the sword master's name cut in the grip of his sword after taking the age range of charcoal used for steel production and usage for several generations of the same names of sword masters into account. (author)

  16. Development of a rapid procedure for the measurement of uranium in drinking water by PERALSR spectrometry

    International Nuclear Information System (INIS)

    Duffey, J.M.; Case, F.I.; Metzger, R.L.; Jessop, B.J.; Schweitzer, G.K.

    1997-01-01

    A new method has been developed for the measurement of U in water samples by selective and quantitative extraction from DTPA solution into an extractive scintillator containing HDEHP and alpha-counting by PERALS R spectrometry. Because this method offers several advantages over the current EPA and ASTM standard test methods for U in drinking water, including speed, simplicity and isotopic information, it has been proposed as a new ASTM standard test method. Sample preparation requires from 1-4 h. Less than 0.5% of Am, Pu, Po, Ra and Th were found to extract under the prescribed conditions. Typical backgrounds are ≤ 0.01 cpm. A comparison of this method with EPA standard method 908.0 and the results of two interlaboratory test of this method are reported. (author)

  17. Aircraft gamma-ray spectrometry in snow-water equivalent measurement

    International Nuclear Information System (INIS)

    Kuittinen, R.; Vironmaeki, J.

    1979-01-01

    During the winter periods 1976-1977 and 1977-1978 the Hydrological Office at the National Board of Waters and the Geological Survey of Finland carried out a joint study to evaluate usefuluess of gamma-ray spectrometry in snow-water equivalent measurement. A multichannel gamma-ray spectrometer was fitted in a DC-3 aircraft. Fourteen snow courses were operated using both the gravimetric method and the gamma-ray method. The snow courses were located in southern Finland in forest, swamp and agricultural land. The results shows that the gamma ray method can be considered suitable for use in Finnish conditions and the accuracy of the gamma-ray method is almost of the same magnitude as the accuracy of the gravimetric method. (Auth.)

  18. Aircraft gamma-ray spectrometry in snow-water equivalent measurement

    Energy Technology Data Exchange (ETDEWEB)

    Kuittinen, R [National Board of Waters (Finland); Vironmaeki, J [Geological Survey of Finland

    1979-01-01

    During the winter periods 1976-1977 and 1977-1978 the Hydrological Office at the National Board of Waters and the Geological Survey of Finland carried out a joint study to evaluate usefuluess of gamma-ray spectrometry in snow-water equivalent measurement. A multichannel gamma-ray spectrometer was fitted in a DC-3 aircraft. Fourteen snow courses were operated using both the gravimetric method and the gamma-ray method. The snow courses were located in southern Finland in forest, swamp and agricultural land. The results shows that the gamma ray method can be considered suitable for use in Finnish conditions and the accuracy of the gamma-ray method is almost of the same magnitude as the accuracy of the gravimetric method.

  19. Improvements on Low Level Activity Gamma Measurements and X-ray Spectrometry at the CEA-MADERE Measurement Platform

    Directory of Open Access Journals (Sweden)

    Sergeyeva Victoria

    2016-01-01

    Full Text Available The CEA MADERE platform (Measurement Applied to DosimEtry in REactors is a part of the Instrumentation Sensors and Dosimetry Laboratory (LDCI. This facility is dedicated to the specific activity measurements of solid and radioactive samples using Gamma and X-ray spectrometry. MADERE is a high-performance facility devoted to neutron dosimetry for experimental programs performed in CEA and for the irradiation surveillance programmes of PWR vessels. The MADERE platform is engaged in a continuous improvement process. Recently, two High Efficiency diodes have been integrated to the MADERE platform in order to manage the accurate low level activity measurements (few Bq per sample. This new equipment provides a good level of efficiency over the energy range from 60 keV to 2 MeV. The background continuum is reduced due to the use of a Ultra Low Background (ULB lead shielding. Relative and absolute X-ray measurement techniques have been improved in order to facilitate absolute rhodium activity measurement (Rh103m on solid samples. Additional efforts have been made to increase the accuracy of the relative niobium (Nb93m activity measurement technique. The way of setting up an absolute measurement method for niobium is under investigation. After a presentation of the MADERE's measurement devices, this paper focuses on the technological options taken into account for the design of high efficiency measurement devices. Then, studies performed on X-ray measurement techniques are presented. Some details about the calculation of uncertainties and correction factors are also mentioned. Finally, future research and development axes are exposed.

  20. Biomedical applications of accelerator mass spectrometry-isotope measurements at the level of the atom.

    Science.gov (United States)

    Barker, J; Garner, R C

    1999-01-01

    Accelerator mass spectrometry (AMS) is a nuclear physics technique developed about twenty years ago, that uses the high energy (several MeV) of a tandem Van de Graaff accelerator to measure very small quantities of rare and long-lived isotopes. Elements that are of interest in biomedicine and environmental sciences can be measured, often to parts per quadrillion sensitivity, i.e. zeptomole to attomole levels (10(-21)-10(-18) mole) from milligram samples. This is several orders of magnitude lower than that achievable by conventional decay counting techniques, such as liquid scintillation counting (LSC). AMS was first applied to geochemical, climatological and archaeological areas, such as for radiocarbon dating (Shroud of Turin), but more recently this technology has been used for bioanalytical applications. In this sphere, most work has been conducted using aluminium, calcium and carbon isotopes. The latter is of special interest in drug metabolism studies, where a Phase 1 adsorption, distribution, metabolism and excretion (ADME) study can be conducted using only 10 nanoCurie (37 Bq or ca. 0.9 microSv) amounts or less of 14C-labelled drugs. In the UK, these amounts of radioactivity are below those necessary to request specific regulatory approval from the Department of Health's Administration of Radioactive Substances Advisory Committee (ARSAC), thus saving on valuable development time and resources. In addition, the disposal of these amounts is much less an environmental issue than that associated with microCurie quantities, which are currently used. Also, AMS should bring an opportunity to conduct "first into man" studies without the need for widespread use of animals. Centre for Biomedical Accelerator Mass Spectrometry (CBAMS) Ltd. is the first fully commercial company in the world to offer analytical services using AMS. With its high throughput and relatively low costs per sample analysis, AMS should be of great benefit to the pharmaceutical and biotechnology

  1. Measuring the radium quartet (228Ra, 226Ra, 224Ra, 223Ra) in seawater samples using gamma spectrometry

    International Nuclear Information System (INIS)

    Beek, P. van; Souhaut, M.; Reyss, J.-L.

    2010-01-01

    Radium isotopes are widely used in marine studies (eg. to trace water masses, to quantify mixing processes or to study submarine groundwater discharge). While 228 Ra and 226 Ra are usually measured using gamma spectrometry, short-lived Ra isotopes ( 224 Ra and 223 Ra) are usually measured using a Radium Delayed Coincidence Counter (RaDeCC). Here we show that the four radium isotopes can be analyzed using gamma spectrometry. We report 226 Ra, 228 Ra, 224 Ra, 223 Ra activities measured using low-background gamma spectrometry in standard samples, in water samples collected in the vicinity of our laboratory (La Palme and Vaccares lagoons, France) but also in seawater samples collected in the plume of the Amazon river, off French Guyana (AMANDES project). The 223 Ra and 224 Ra activities determined in these samples using gamma spectrometry were compared to the activities determined using RaDeCC. Activities determined using the two techniques are in good agreement. Uncertainties associated with the 224 Ra activities are similar for the two techniques. RaDeCC is more sensitive for the detection of low 223 Ra activities. Gamma spectrometry thus constitutes an alternate method for the determination of short-lived Ra isotopes.

  2. Study on the Effects of Sample Density on Gamma Spectrometry System Measurement Efficiency at Radiochemistry and Environment Laboratory

    International Nuclear Information System (INIS)

    Wo, Y.M.; Dainee Nor Fardzila Ahmad Tugi; Khairul Nizam Razali

    2015-01-01

    The effects of sample density on the measurement efficiency of the gamma spectrometry system were studied by using four sets multi nuclide standard sources of various densities between 0.3 - 1.4 g/ ml. The study was conducted on seven unit 25 % coaxial HPGe detector gamma spectrometry systems in Radiochemistry and Environment Laboratory (RAS). Difference on efficiency against gamma emitting radionuclides energy and measurement systems were compared and discussed. Correction factor for self absorption caused by difference in sample matrix density of the gamma systems were estimated. The correction factors are to be used in quantification of radionuclides concentration in various densities of service and research samples in RAS. (author)

  3. Effect of dimethylamine on the gas phase sulfuric acid concentration measured by Chemical Ionization Mass Spectrometry

    CERN Document Server

    Rondo, L.; Kürten, A.; Adamov, A.; Bianchi, F.; Breitenlechner, M.; Duplissy, J.; Franchin, A.; Dommen, J.; Donahue, N. M.; Dunne, E. M.; Flagan, R. C.; Hakala, J.; Hansel, A.; Keskinen, H.; Kim, J.; Jokinen, T.; Lehtipalo, K.; Leiminger, M.; Praplan, A.; Riccobono, F.; Rissanen, M. P.; Sarnela, N.; Schobesberger, S.; Simon, M.; Sipilä, M.; Smith, J. N.; Tomé, A.; Tröstl, J.; Tsagkogeorgas, G.; Vaattovaara, P.; Winkler, P. M.; Williamson, C.; Wimmer, D.; Baltensperger, U.; Kirkby, J.; Kulmala, M.; Petäjä, T.; Worsnop, D. R.; Curtius, J.

    2016-01-01

    Sulfuric acid is widely recognized as a very important substance driving atmospheric aerosolnucleation. Based on quantum chemical calculations it has been suggested that the quantitative detectionof gas phase sulfuric acid (H2SO4) by use of Chemical Ionization Mass Spectrometry (CIMS) could be biased inthe presence of gas phase amines such as dimethylamine (DMA). An experiment (CLOUD7 campaign) was setup at the CLOUD (Cosmics Leaving OUtdoor Droplets) chamber to investigate the quantitative detection ofH2SO4in the presence of dimethylamine by CIMS at atmospherically relevant concentrations. For the first time inthe CLOUD experiment, the monomer sulfuric acid concentration was measured by a CIMS and by two CI-APi-TOF(Chemical Ionization-Atmospheric Pressure interface-Time Of Flight) mass spectrometers. In addition, neutralsulfuric acid clusters were measured with the CI-APi-TOFs. The CLOUD7 measurements show that in the presenceof dimethylamine (<5 to 70 pptv) the sulfuric acid monomer measured by the CIMS...

  4. Burn-up measurements of spent fuel using gamma spectrometry technique

    International Nuclear Information System (INIS)

    Pereda, C.; Henriquez, C.; Klein, J.; Medel, J.

    2005-01-01

    Burn-up results obtained for HEU (45% of 235 U) fuel assemblies of the RECH-1 Research Reactor using gamma spectrometry technique are presented. The spectra were got from an in-pool facility built in the reactor to be mainly used to measure the burnup of irradiated fuel assemblies with short cooling time, where 95 Zr is being evaluated as possible fission monitor. A program to measure all spent fuel assemblies of the RECH-1 reactor was initiated in the frame of the Regional Project RLA/4/018: 'Management of Spent Fuel from Research Reactors'. The results presented here were obtained from HEU spent fuel assemblies with cooling time greater than 100 days and 137 Cs was used as fission monitor. The efficiency of the in-pool system was determined using a slightly burnt experimental fuel assembly, which has one fuel plate (one of the outer plates) and the rest are dummy plates. An average burn-up of 2.8% of 235 U was previously measured for the experimental fuel assembly utilizing a facility installed in a hot cell and 137 Cs was used as monitor. (author)

  5. An Interlaboratory Evaluation of Drift Tube Ion Mobility–Mass Spectrometry Collision Cross Section Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Stow, Sarah M. [Department; Causon, Tim J. [Division; Zheng, Xueyun [Biological; Kurulugama, Ruwan T. [Agilent Technologies, Santa Clara, California 95051, United States; Mairinger, Teresa [Division; May, Jody C. [Department; Rennie, Emma E. [Agilent Technologies, Santa Clara, California 95051, United States; Baker, Erin S. [Biological; Smith, Richard D. [Biological; McLean, John A. [Department; Hann, Stephan [Division; Fjeldsted, John C. [Agilent Technologies, Santa Clara, California 95051, United States

    2017-08-14

    Collision cross section (CCS) measurements resulting from ion mobility-mass spectrometry (IM-MS) experiments provide a promising orthogonal dimension of structural information in MS-based analytical separations. As with any molecular identifier, interlaboratory standardization must precede broad range integration into analytical workflows. In this study, we present a reference drift tube ion mobility mass spectrometer (DTIM-MS) where improvements on the measurement accuracy of experimental parameters influencing IM separations provide standardized drift tube, nitrogen CCS values (DTCCSN2) for over 120 unique ion species with the lowest measurement uncertainty to date. The reproducibility of these DTCCSN2 values are evaluated across three additional laboratories on a commercially available DTIM-MS instrument. The traditional stepped field CCS method performs with a relative standard deviation (RSD) of 0.29% for all ion species across the three additional laboratories. The calibrated single field CCS method, which is compatible with a wide range of chromatographic inlet systems, performs with an average, absolute bias of 0.54% to the standardized stepped field DTCCSN2 values on the reference system. The low RSD and biases observed in this interlaboratory study illustrate the potential of DTIM-MS for providing a molecular identifier for a broad range of discovery based analyses.

  6. Estimation of natural potassium concentration in Romanian males by in vivo gamma-ray spectrometry measurements

    International Nuclear Information System (INIS)

    Mirela Angela Saizu

    2012-01-01

    At the Whole Body Monitoring Laboratory, from IFIN-HH, Bucharest, Romania, there were performed in vivo gamma-ray spectrometry measurements on 108 Romanian males in order to evaluate the mineral natural potassium content in human body, as total value and concentration. The measurements were performed with a shadow shield whole body counter, tilted chair geometry, based on a shielded NaI(Tl) scintillation detector of 12.5 cm (diameter) x 10 cm (height) crystal size. The results revealed a calculated value of the mean total body potassium (TBK) of 135.03 ± 2.94 g and a value of 1.9 ± 0.022 g of potassium/kg of body weight for the mean body potassium concentration, for the measured males. These values are similar with the values declared for the Reference Man, in ICRP23. Correlations between total body potassium, potassium concentration and age, weight and Body Build Index were investigated and peculiar conclusions were resulted. (author)

  7. Accurate γ-ray spectrometry measurements of the half-life of 92Sr

    International Nuclear Information System (INIS)

    Leconte, P.; Hudelot, J.P.; Antony, M.

    2008-01-01

    Studies of the nuclear fuel cycle require an accurate knowledge of the energy release from the decay of radioactive nuclides produced in a reactor, including precise half-life data for the short-lived radionuclides. Moreover, short-lived fission products are crucial for fission rate distribution measurements performed in low-power facilities, such as EOLE and MINERVE of CEA Cadarache [Fougeras, P., 2005. EOLE, MINERVE and MASURCA facilities and their associated neutron experimental programs. In: 13th International Conference on Nuclear Engineering, Beijing, China, 16-20 May 2005], and their nuclear decay data need to be known to high precision. For these reasons, the half-life of 92 Sr has been measured to solve a recently observed inconsistency identified with the quoted value in the main nuclear applications libraries (including JEFF3.1): T 1/2 =2.71±0.01 h [Parsa, B., Ashari, A., Goolvard, L., Nobar, Y.M., 1971. Decay scheme of 2.71 h 92 Sr. Nucl. Phys. A 175, 629-640]. An overestimation of 4.5% has been identified in this work, based on two independent methods. Specific γ-ray spectrometry measurements on activated fissile foils have been carried out, using two HPGe detectors. Influencing factors such as net area measurements of photopeaks, pulse pile-up accuracy and dead time corrections in the presence of decaying activity are discussed. A new value has been obtained by combining eight series of measurements: T 1/2 =2.594±0.006 h. The uncertainty has been reduced by a factor of two with respect to previous evaluations. This measured value also shows good agreement with the most recent studies of T 1/2 =2.627±0.009 h [Nir-El, Y., 2003. Private Communications. Soreq Research Centre, Yavne, Israel

  8. Development and calibration automatic equipment's measuring in real time of the environmental radioactivity by gamma spectrometry

    International Nuclear Information System (INIS)

    Casanovas, R.; Morant, J. J.; Salvado, M.

    2013-01-01

    In this paper, we describe the general aspects of the implementation of gamma spectrometry in water, as well as the development of two measuring devices based on this technique: aerosol monitor (RARM-F) and a monitor direct measurement (RARMD2) , both patent applications. Furthermore, they described in detail the aspects of calibration of equipment, which has been made by combining experimental measurements with Monte Carlo simulations. (Author)

  9. Measurement of Muscle Protein Fractional Synthetic Rate by Capillary Gas Chromatography/Combustion Isotope Ratio Mass Spectrometry

    OpenAIRE

    Yarasheski, Kevin E.; Smith, Kenneth; Rennie, Michael J.; Bier, Dennis M.

    1992-01-01

    The measurement of skeletal muscle protein fractional synthetic rate using an infusion of (1-13C)leucine and measuring the isotopic abundance of the tracer in skeletal muscle protein by preparative gas chromatography (GC)/ninhydrin isotope ratio mass spectrometry (IRMS) is laborious and subject to errors owing to contamination by 12C. The purpose of this study was to compare muscle (13C)leucine enrichment measured with the conventional preparative GC/ninhydrin IRMS approach to a new, continuo...

  10. Flask sample measurements for CO2, CH4 and CO using cavity ring-down spectrometry

    Science.gov (United States)

    Wang, J.-L.; Jacobson, G.; Rella, C. W.; Chang, C.-Y.; Liu, I.; Liu, W.-T.; Chew, C.; Ou-Yang, C.-F.; Liao, W.-C.; Chang, C.-C.

    2013-08-01

    In recent years, cavity ring-down spectrometry (CRDS) has been demonstrated to be a highly sensitive, stable and fast analytical technique for real-time in situ measurements of greenhouse gases. In this study, we propose the technique (which we call flask-CRDS) of analyzing whole air flask samples for CO2, CH4 and CO using a custom gas manifold designed to connect to a CRDS analyzer. Extremely stable measurements of these gases can be achieved over a large pressure range in the flask, from 175 to 760 Torr. The wide pressure range is conducive to flask sample measurement in three ways: (1) flask samples can be collected in low-pressure environments (e.g. high-altitude locations); (2) flask samples can be first analyzed for other trace gases with the remaining low-pressure sample for CRDS analysis of CO2, CH4 and CO; and (3) flask samples can be archived and re-analyzed for validation. The repeatability of this method (1σ of 0.07 ppm for CO2, 0.4 ppb for CH4, and 0.5 ppb for CO) was assessed by analyzing five canisters filled with the same air sample to a pressure of 200 Torr. An inter-comparison of the flask-CRDS data with in-situ CRDS measurements at a high-altitude mountain baseline station revealed excellent agreement, with differences of 0.10 ± 0.09 ppm (1σ) for CO2 and 0.9 ± 1.0 ppb for CH4. This study demonstrated that the flask-CRDS method was not only simple to build and operate but could also perform highly accurate and precise measurements of atmospheric CO2, CH4 and CO in flask samples.

  11. Significance of radioelement concentration measurements made by airborne gamma-ray spectrometry over the Canadian Shield

    International Nuclear Information System (INIS)

    Charbonneau, B.W.; Killeen, P.G.; Carson, J.M.; Cameron, G.W.; Richardson, K.A.

    1976-01-01

    Results of airborne gamma-ray spectrometer surveys conducted by the Geological Survey of Canada are presented as maps contoured in units of radioelement and concentration ratios. These contoured values represent the average surface concentrations of the radioelements over areas of the order of several square kilometres. The relationship between this ''average surface concentration'' and the radioelement concentration in bedrock underlying the area depends on: (1) the percentage of outcrop; (2) the relation between overburden and bedrock radioelement concentration; (3) percentage of marshland or surface water in the area; (4) soil moisture; and (5) density of vegetation. More than 2500 portable gamma-ray spectrometer analyses of outcrop and overburden have been made in the Bancroft, Elliot Lake and Fort Smith areas of the Canadian Precambrian Shield. In the areas examined, the radioelement concentrations in glacial drift reflect the concentrations in the underlying bedrock. Rocks with near-crustal average contents of thorium, uranium and potassium are overlain by glacial drift having approximately the same concentrations. As the concentration in bedrock increases, the concentration in the local overburden also increases, but not to the same extent. In addition, in-situ gamma-ray spectrometry measurements were made at almost 1000 stations within the area of airborne surveys near Mont Laurier and Elliot Lake. These ground measurements were compared with the airborne measurements by averaging the values for all those ground stations located in the areas between each contour level on airborne maps. Radioelement concentrations in bedrock are considerably higher than corresponding airborne measurements, and this difference between bedrock and airborne values increases at higher radioelement concentrations. Radioelement concentrations in glacial drift are only slightly higher than airborne contour values for the same area. Airborne contour maps of the radioelement ratios

  12. Novel method for measurement of glutathione kinetics in neonates using liquid chromatography coupled to isotope ratio mass spectrometry

    NARCIS (Netherlands)

    Schierbeek, Henk; te Braake, Frans; Godin, Jean-Philippe; Fay, Laurent-Bernard; van Goudoever, Johannes B.

    2007-01-01

    A novel analytical method using liquid chromatography coupled to isotope ratio mass spectrometry (LC/IRMS) was developed for measuring the fractional synthesis rate (FSR) of glutathione (GSH) in neonates after infusion of [1-(13)C]-glycine as a tracer. After transformation of GSH into GSSG, its

  13. Elements in normal and cirrhotic human liver. Potassium, iron, copper, zinc and bromine measured by X-ray fluorescence spectrometry

    DEFF Research Database (Denmark)

    Laursen, J.; Milman, N.; Leth, Peter Mygind

    1990-01-01

    Various elements (K, Fe, Cu, Zn, Br) were measured by X-ray flourescence spectrometry in cellular and connective tissue fractions of normal and cirrhotic liver samples obtained at autopsy. Normal livers: 32 subjects (16 males, 16 females) median age 69 years. Cirrhotic livers: 14 subjects (13 mal...

  14. Nuclear Forensics: Measurements of Uranium Oxides Using Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS)

    Science.gov (United States)

    2010-03-01

    Isotope Ratio Analysis of Actinides , Fission Products, and Geolocators by High- efficiency Multi-collector Thermal Ionization Mass Spectrometry...Information, 1999. Hou, Xiaolin, and Per Roos. “ Critical Comparison of radiometric and Mass Spectrometric Methods for the Determination of...NUCLEAR FORENSICS: MEASUREMENTS OF URANIUM OXIDES USING TIME-OF-FLIGHT SECONDARY ION MASS

  15. On copper diffusion in silicon measured by glow discharge mass spectrometry.

    Science.gov (United States)

    Modanese, Chiara; Gaspar, Guilherme; Arnberg, Lars; Di Sabatino, Marisa

    2014-11-01

    Copper contamination occurs frequently in silicon for photovoltaic applications due to its very fast diffusion coupled with a low solid solubility, especially at room temperature. The combination of these properties exerts a challenge on the direct analysis of Cu bulk concentration in Si by sputtering techniques like glow discharge mass spectrometry (GDMS). This work aims at addressing the challenges in quantitative analysis of fast diffusing elements in Si matrix by GDMS. N-type, monocrystalline (Czochralski) silicon samples were intentionally contaminated with Cu after solidification and consequently annealed at 900 °C to ensure a homogeneous distribution of Cu in the bulk. The samples were quenched after annealing to control the extent of the diffusion to the surface prior to the GDMS analyses, which were carried out at different time intervals from within few minutes after cooling onward. The Cu profiles were measured by high-resolution GDMS operating in a continuous direct current mode, where the integration step length was set to ∼0.5 μm over a total sputtered depth of 8-30 μm. The temperature of the samples during the GDMS analyses was also measured in order to evaluate the diffusion. The Cu contamination of n-type Si samples was observed to be highly material dependent. The practical impact of Cu out-diffusion on the calculation of the relative sensitivity factor (RSF) of Cu in Si is discussed.

  16. Comparison of femtosecond and nanosecond laser ablation inductively coupled plasma mass spectrometry for uranium isotopic measurements

    Energy Technology Data Exchange (ETDEWEB)

    Havrilla, George Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); McIntosh, Kathryn Gallagher [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Judge, Elizabeth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dirmyer, Matthew R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Campbell, Keri [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Gonzalez, Jhanis J. [Applied Spectra Inc., Fremont, CA (United States)

    2016-10-20

    Feasibility tests were conducted using femtosecond and nanosecond laser ablation inductively coupled plasma mass spectrometry for rapid uranium isotopic measurements. The samples used in this study consisted of a range of pg quantities of known 235/238 U solutions as dried spot residues of 300 pL drops on silicon substrates. The samples spanned the following enrichments of 235U: 0.5, 1.5, 2, 3, and 15.1%. In this direct comparison using these particular samples both pulse durations demonstrated near equivalent data can be produced on either system with respect to accuracy and precision. There is no question that either LA-ICP-MS method offers the potential for rapid, accurate and precise isotopic measurements of U10Mo materials whether DU, LEU or HEU. The LA-ICP-MS equipment used for this work is commercially available. The program is in the process of validating this work for large samples using center samples strips from Y-12 MP-1 LEU-Mo Casting #1.

  17. Comparison of femtosecond and nanosecond laser ablation inductively coupled plasma mass spectrometry for uranium isotopic measurements

    International Nuclear Information System (INIS)

    Havrilla, George Joseph; McIntosh, Kathryn Gallagher; Judge, Elizabeth; Dirmyer, Matthew R.; Campbell, Keri; Gonzalez, Jhanis J.

    2016-01-01

    Feasibility tests were conducted using femtosecond and nanosecond laser ablation inductively coupled plasma mass spectrometry for rapid uranium isotopic measurements. The samples used in this study consisted of a range of pg quantities of known 235/238 U solutions as dried spot residues of 300 pL drops on silicon substrates. The samples spanned the following enrichments of 235 U: 0.5, 1.5, 2, 3, and 15.1%. In this direct comparison using these particular samples both pulse durations demonstrated near equivalent data can be produced on either system with respect to accuracy and precision. There is no question that either LA-ICP-MS method offers the potential for rapid, accurate and precise isotopic measurements of U10Mo materials whether DU, LEU or HEU. The LA-ICP-MS equipment used for this work is commercially available. The program is in the process of validating this work for large samples using center samples strips from Y-12 MP-1 LEU-Mo Casting #1.

  18. Empirical Correction for Differences in Chemical Exchange Rates in Hydrogen Exchange-Mass Spectrometry Measurements.

    Science.gov (United States)

    Toth, Ronald T; Mills, Brittney J; Joshi, Sangeeta B; Esfandiary, Reza; Bishop, Steven M; Middaugh, C Russell; Volkin, David B; Weis, David D

    2017-09-05

    A barrier to the use of hydrogen exchange-mass spectrometry (HX-MS) in many contexts, especially analytical characterization of various protein therapeutic candidates, is that differences in temperature, pH, ionic strength, buffering agent, or other additives can alter chemical exchange rates, making HX data gathered under differing solution conditions difficult to compare. Here, we present data demonstrating that HX chemical exchange rates can be substantially altered not only by the well-established variables of temperature and pH but also by additives including arginine, guanidine, methionine, and thiocyanate. To compensate for these additive effects, we have developed an empirical method to correct the hydrogen-exchange data for these differences. First, differences in chemical exchange rates are measured by use of an unstructured reporter peptide, YPI. An empirical chemical exchange correction factor, determined by use of the HX data from the reporter peptide, is then applied to the HX measurements obtained from a protein of interest under different solution conditions. We demonstrate that the correction is experimentally sound through simulation and in a proof-of-concept experiment using unstructured peptides under slow-exchange conditions (pD 4.5 at ambient temperature). To illustrate its utility, we applied the correction to HX-MS excipient screening data collected for a pharmaceutically relevant IgG4 mAb being characterized to determine the effects of different formulations on backbone dynamics.

  19. Dissolved atmospheric gas in xylem sap measured with membrane inlet mass spectrometry.

    Science.gov (United States)

    Schenk, H Jochen; Espino, Susana; Visser, Ate; Esser, Bradley K

    2016-04-01

    A new method is described for measuring dissolved gas concentrations in small volumes of xylem sap using membrane inlet mass spectrometry. The technique can be used to determine concentrations of atmospheric gases, such as argon, as reported here, or for any dissolved gases and their isotopes for a variety of applications, such as rapid detection of trace gases from groundwater only hours after they were taken up by trees and rooting depth estimation. Atmospheric gas content in xylem sap directly affects the conditions and mechanisms that allow for gas removal from xylem embolisms, because gas can dissolve into saturated or supersaturated sap only under gas pressure that is above atmospheric pressure. The method was tested for red trumpet vine, Distictis buccinatoria (Bignoniaceae), by measuring atmospheric gas concentrations in sap collected at times of minimum and maximum daily temperature and during temperature increase and decline. Mean argon concentration in xylem sap did not differ significantly from saturation levels for the temperature and pressure conditions at any time of collection, but more than 40% of all samples were supersaturated, especially during the warm parts of day. There was no significant diurnal pattern, due to high variability between samples. © 2015 John Wiley & Sons Ltd.

  20. Application of simulated standard spectra in natural radioactivity measurements using gamma spectrometry

    International Nuclear Information System (INIS)

    Narayani, K.; Pant, A.D.; Bhosle, Nitin; Anilkumar, S.; Singh, Rajvir; Pradeepkumar, K.S.

    2014-01-01

    Gamma ray spectrometry is one of the well known analytical techniques for environmental radioactivity measurements. Gamma spectrometer based on NaI(Tl) scintillation detectors is very popular since it offers high efficiency, low cost and case in handling. The poor energy resolution of the NaI(TI) detector is the major disadvantage making tile analysis of complex gamma ray spectra difficult. Least square method or the full spectrum analysis method is widely used for the analysis of complex spectra from scintillation detectors. The main requirement of this method is that the individual standard spectra of all nuclides expected in the complex spectrum in the same measurement geometry must be available. It is not always possible and feasible to have all the standards of nuclides in the desired geometry. A methodology based on the use of simulated standard spectra generated by Monte Carlo technique was proposed for analysis of complex spectra of nuclides. In the present work, for the analysis of 238 U, 233 Th and 40 K in soil samples, the same methodology was applied by using the simulated standard spectra in soil matrix. The details of the simulation method and results analysis of 238 U, 232 Th and 40 K in environmental samples are discussed in this paper

  1. Study of principle error sources in gamma spectrometry. Application to cross sections measurement

    International Nuclear Information System (INIS)

    Majah, M. Ibn.

    1985-01-01

    The principle error sources in gamma spectrometry have been studied in purpose to measure cross sections with great precision. Three error sources have been studied: dead time and pile up which depend on counting rate, and coincidence effect that depends on the disintegration scheme of the radionuclide in question. A constant frequency pulse generator has been used to correct the counting loss due to dead time and pile up in cases of long and short disintegration periods. The loss due to coincidence effect can reach 25% and over, depending on the disintegration scheme and on the distance source-detector. After establishing the correction formula and verifying its validity for four examples: iron 56, scandium 48, antimony 120 and gold 196 m, an application has been done by measuring cross sections of nuclear reactions that lead to long disintegration periods which need short distance source-detector counting and thus correcting the loss due to dead time effect, pile up and coincidence effect. 16 refs., 45 figs., 25 tabs. (author)

  2. A high-throughput mass spectrometry assay to simultaneously measure intact insulin and C-peptide.

    Science.gov (United States)

    Taylor, Steven W; Clarke, Nigel J; Chen, Zhaohui; McPhaul, Michael J

    2016-04-01

    Measurements of fasting levels of insulin and C-peptide are useful in documenting insulin resistance and may help predict development of diabetes mellitus. However, the specific insulin and C-peptide levels associated with specific degrees of insulin resistance have not been defined, owing to marked variability among immunoassays and lack of standardization. Herein, we describe a multiplexed liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay for intact insulin and C-peptide. Insulin and C-peptide were enriched from patient sera using monoclonal antibodies immobilized on magnetic beads and processed on a robotic liquid handler. Eluted peptides were analyzed by LC-MS/MS. Bovine insulin and a stable isotopically-labeled (13C/15N) C-peptide were utilized as internal standards. The assay had an analytical measurement range of 3 to 320 μIU/ml (18 to 1920 pmol/l) for insulin and 0.11 to 27.2 ng/ml (36 to 9006 pmol/l) for C-peptide. Intra- and inter-day assay variation was less than 11% for both peptides. Of the 5 insulin analogs commonly prescribed to treat diabetes, only the recombinant drug insulin lispro caused significant interference for the determination of endogenous insulin. There were no observed interferences for C-peptide. We developed and validated a high-throughput, quantitative, multiplexed LC-MS/MS assay for intact insulin and C-peptide. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. High-precision lead isotope ratio measurement by inductively coupled plasma multiple collector mass spectrometry

    International Nuclear Information System (INIS)

    Walder, A.J.; Furuta, Naoki.

    1993-01-01

    An inductively coupled plasma (ICP) ion source coupled to a magnetic sector mass analyser equipped with seven Faraday detectors has been used to measure the lead isotope ratios in solutions of Sanshiro Pond sediment collected at the University of Tokyo, airborne particulates collected at Shinjuku in Tokyo and Merck multielement standard product number 97279494. A thallium correction technique was utilized to allow a simultaneous correction for mass bias. This work followed an earlier interlaboratory comparison study of the above-mentioned solutions using ICP quadrupole mass spectrometry, and has demonstrated a considerable improvement in analytical precision. The following isotope ratio measurements were recorded. Pond sediment solution containing 82 ng ml -1 lead: 206 Pb/ 204 Pb=17.762±0.014; 206 Pb/ 207 Pb=1.1424±0.0009; 208 Pb/ 204 Pb=37.678±0.034. Airborne particulate solution containing 45 ng ml -1 lead: 206 Pb/ 204 Pb=17.969±0.006; 206 Pb/ 207 Pb=1.1528±0.0003; 208 Pb/ 204 Pb=37.915±0.021. Merck multielement standard solution containing 100 ng ml -1 lead: 206 Pb/ 204 Pb=19.255±0.015; 206 Pb/ 207 Pb=1.2238±0.0004; 208 Pb/ 204 Pb=38.476±0.021 (All errors are given as ±2 standard deviations). (author)

  4. High-precision measurements of seawater Pb isotope compositions by double spike thermal ionization mass spectrometry.

    Science.gov (United States)

    Paul, Maxence; Bridgestock, Luke; Rehkämper, Mark; van DeFlierdt, Tina; Weiss, Dominik

    2015-03-10

    A new method for the determination of seawater Pb isotope compositions and concentrations was developed, which combines and optimizes previously published protocols for the separation and isotopic analysis of this element. For isotopic analysis, the procedure involves initial separation of Pb from 1 to 2L of seawater by co-precipitation with Mg hydroxide and further purification by a two stage anion exchange procedure. The Pb isotope measurements are subsequently carried out by thermal ionization mass spectrometry using a (207)Pb-(204)Pb double spike for correction of instrumental mass fractionation. These methods are associated with a total procedural Pb blank of 28±21 pg (1sd) and typical Pb recoveries of 40-60%. The Pb concentrations are determined by isotope dilution (ID) on 50 mL of seawater, using a simplified version of above methods. Analyses of multiple aliquots of six seawater samples yield a reproducibility of about ±1 to ±10% (1sd) for Pb concentrations of between 7 and 50 pmol/kg, where precision was primarily limited by the uncertainty of the blank correction (12±4 pg; 1sd). For the Pb isotope analyses, typical reproducibilities (±2sd) of 700-1500 ppm and 1000-2000 ppm were achieved for (207)Pb/(206)Pb, (208)Pb/(206)Pb and (206)Pb/(204)Pb, (207)Pb/(204)Pb, (208)Pb/(204)Pb, respectively. These results are superior to literature data that were obtained using plasma source mass spectrometry and they are at least a factor of five more precise for ratios involving the minor (204)Pb isotope. Both Pb concentration and isotope data, furthermore, show good agreement with published results for two seawater intercomparison samples of the GEOTRACES program. Finally, the new methods were applied to a seawater depth profile from the eastern South Atlantic. Both Pb contents and isotope compositions display a smooth evolution with depth, and no obvious outliers. Compared to previous Pb isotope data for seawater, the (206)Pb/(204)Pb ratios are well correlated

  5. Airborne gamma spectrometry measurements in the context of the exercise ARM02

    International Nuclear Information System (INIS)

    Bucher, B.; Rybach, L.; Schwarz, G.; Baerlocher, C.

    2003-05-01

    The international exercise under the European Union project ECCOMAGS (European Coordination and Calibration of Mobile and Airborne Gamma Spectrometry) stood in the centre of the yearly airborne gamma spectrometry measurement flights which were carried out in the time of 27 -31 May 2002. The exercise was held in Southwest Scotland in the region of Dumfries and Galloway. Unfortunately due to difficulties with flight approvals for military aircrafts data could be taken in the exercise area only on the flight back to Switzerland. Immediately after returning to Switzerland the regular measurements around the nuclear power plants Beznau (KKB) and Leibstadt (KKL), around the intermediate storage facilities for radioactive waste (ZWILAG) and around the research facility Paul Scherrer Institute were performed. The flights took place in the context of the exercise ARM02 and were lead by the Swiss National Emergency Operations Centre (NAZ). Unfortunately just a few measurements in the common intercalibration areas could be taken on the flight back from the international exercise. Nevertheless comparisons of the results with those of other European teams could be made. These comparisons proved the good calibration of our equipment. On the flight back measurements were also carried out at great altitude above the sea. This data allowed to determine very well the background of the aircraft and the cosmic stripping ratios. In the context of the regular measurements in the environs of the nuclear facilities in Switzerland the areas around the nuclear power plants Beznau and Leibstadt and around the nuclear research facility Paul Scherrer Institute were measured. The results were very similar to the results of earlier measurements in the last years. The nuclear power plant Beznau couldn't be recognised on the activity maps. But the nuclear power plant Leibstadt could be identified by its direct radiation which is specific for this type of reactor (BWR). At the site of the Paul

  6. Assessment of measurement result uncertainty in determination of 210Pb with the focus on matrix composition effect in gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Iurian, A.R.; Pitois, A.; Kis-Benedek, G.; Migliori, A.; Padilla-Alvarez, R.; Ceccatelli, A.

    2016-01-01

    Reference materials were used to assess measurement result uncertainty in determination of 210 Pb by gamma-ray spectrometry, liquid scintillation counting, or indirectly by alpha-particle spectrometry, using its daughter 210 Po in radioactive equilibrium. Combined standard uncertainties of 210 Pb massic activities obtained by liquid scintillation counting are in the range 2–12%, depending on matrices and massic activity values. They are in the range 1–3% for the measurement of its daughter 210 Po using alpha-particle spectrometry. Three approaches (direct computation of counting efficiency and efficiency transfer approaches based on the computation and, respectively, experimental determination of the efficiency transfer factors) were applied for the evaluation of 210 Pb using gamma-ray spectrometry. Combined standard uncertainties of gamma-ray spectrometry results were found in the range 2–17%. The effect of matrix composition on self-attenuation was investigated and a detailed assessment of uncertainty components was performed. - Highlights: • Confirmed 210 Pb certified values by LSC and alpha-particle spectrometry ( 210 Po). • Assessed 210 Po measurement result uncertainty by alpha-particle spectrometry. • Matrix composition effect on gamma-ray spectrometry measurement result uncertainty. • Assessment of 210 Pb measurement result uncertainty by gamma-ray spectrometry. • Comparison of techniques and approaches: ‘fit-for-purpose’ considerations.

  7. Simultaneous measurement of the concentrations of soot particles and gas species in light hydrocarbon flames using mass spectrometry

    International Nuclear Information System (INIS)

    Li, Qingxun; Liu, Fang; Wang, Dezheng; Wang, Tiefeng

    2014-01-01

    Besides gas species concentrations, soot volume fractions are also important data in the study of flames. This work describes the simultaneous measurement of the concentrations of soot and gas species in light hydrocarbon flames by in situ sampling and mass spectrometry (MS).The reaction medium was frozen by sampling into a very low-pressure tube, and the soot selectivity (proportion of carbon atoms in the reactant converted to soot) was determined from the C and H mass balances using the measured concentrations of the gas species and the mass of soot present per unit gas volume. The H/C ratio of the soot was measured by a thermogravimetry–mass spectrometry combination. The soot volume fraction was calculated from the soot selectivity and density of the soot. The soot selectivity measured by this reduced pressure sampling mass spectrometry (RPSMS) method was verified by measurements using the gravimetric sampling technique where the mass of soot collected in a volume of gas was weighed by a high precision balance. For most of the measurements, the uncertainty in the soot volume fraction was ±5%, but this would be larger when the soot volume fractions are less than 1 ppm. For demonstration, the RPSMS method was used to study a methane fuel-rich flame where the soot volume fractions were 1–5 ppm. The simultaneous measurement of concentrations of soot and gas species is useful for the quantitative study of flames. (paper)

  8. Reactions of nitrite with hemoglobin measured by membrane inlet mass spectrometry

    Science.gov (United States)

    Tu, Chingkuang; Mikulski, Rose; Swenson, Erik R.; Silverman, David N.

    2010-01-01

    Membrane inlet mass spectrometry was used to observe nitric oxide in the well-studied reaction of nitrite with hemoglobin. The membrane inlet was submerged in the reaction solutions and measured NO in solution via its flux across a semipermeable membrane leading to the mass spectrometer detecting the mass-to-charge ratio m/z 30. This method measures NO directly in solution and is an alternate approach compared with methods that purge solutions to measure NO. Addition to deoxy-Hb(FeII) (near 38 µM heme concentration) of nitrite in a range of 80 µM to 16 mM showed no accumulation of either NO or N2O3 on a physiologically relevant time scale with a sensitivity near 1 nM. The addition of nitrite to oxy-Hb(FeII) and met-Hb(FeIII) did not accumulate free NO to appreciable extents. These observations show that for several minutes after mixing nitrite with hemoglogin, free NO does not accumulate to levels exceeding the equilibrium level of NO. The presence of cyanide ions did not alter the appearance of the data; however, the presence of 2 mM mercuric ions at the beginning of the experiment with deoxy-Hb(FeII) shortened the initial phase of NO accumulation and increased the maximal level of free, unbound NO by about twofold. These experiments appear consistent with no role of met-Hb(FeIII) in the generation of NO and an increase in nitrite reductase activity caused by the presumed binding of mercuric to cysteine residues. These results raise questions about the ability of reduction of nitrite mediated by deoxy-Hb(FeII) to play a role in vasodilation. PMID:18848984

  9. Quantitative images of metals in plant tissues measured by laser ablation inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Becker, J.S.; Dietrich, R.C.; Matusch, A.; Pozebon, D.; Dressler, V.L.

    2008-01-01

    Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was used for quantitative imaging of toxic and essential elements in thin sections (thickness of 30 or 40 μm) of tobacco plant tissues. Two-dimensional images of Mg, Fe, Mn, Zn, Cu, Cd, Rh, Pt and Pb in leaves, shoots and roots of tobacco were produced. Sections of the plant tissues (fixed onto glass slides) were scanned by a focused beam of a Nd:YAG laser in a laser ablation chamber. The ablated material was transported with argon as carrier gas to the ICP ion source at a quadrupole ICP-MS instrument. Ion intensities of the investigated elements were measured together with 13 C + , 33 S + and 34 S + within the entire plant tissue section. Matrix matching standards (prepared using powder of dried tobacco leaves) were used to constitute calibration curves, whereas the regression coefficient of the attained calibration curves was typically 0.99. The variability of LA-ICP-MS process, sample heterogeneity and water content in the sample were corrected by using 13 C + as internal standard. Quantitative imaging of the selected elements revealed their inhomogeneous distribution in leaves, shoots and roots

  10. A mass spectrometry-based assay for improved quantitative measurements of efflux pump inhibition.

    Directory of Open Access Journals (Sweden)

    Adam R Brown

    Full Text Available Bacterial efflux pumps are active transport proteins responsible for resistance to selected biocides and antibiotics. It has been shown that production of efflux pumps is up-regulated in a number of highly pathogenic bacteria, including methicillin resistant Staphylococcus aureus. Thus, the identification of new bacterial efflux pump inhibitors is a topic of great interest. Existing assays to evaluate efflux pump inhibitory activity rely on fluorescence by an efflux pump substrate. When employing these assays to evaluate efflux pump inhibitory activity of plant extracts and some purified compounds, we observed severe optical interference that gave rise to false negative results. To circumvent this problem, a new mass spectrometry-based method was developed for the quantitative measurement of bacterial efflux pump inhibition. The assay was employed to evaluate efflux pump inhibitory activity of a crude extract of the botanical Hydrastis Canadensis, and to compare the efflux pump inhibitory activity of several pure flavonoids. The flavonoid quercetin, which appeared to be completely inactive with a fluorescence-based method, showed an IC50 value of 75 μg/mL with the new method. The other flavonoids evaluated (apigenin, kaempferol, rhamnetin, luteolin, myricetin, were also active, with IC50 values ranging from 19 μg/mL to 75 μg/mL. The assay described herein could be useful in future screening efforts to identify efflux pump inhibitors, particularly in situations where optical interference precludes the application of methods that rely on fluorescence.

  11. Isotopic abundance measurements on solid nuclear-type samples by glow discharge mass spectrometry

    International Nuclear Information System (INIS)

    Betti, M.; Rasmussen, G.; Koch, L.

    1996-01-01

    A double-focusing glow discharge mass spectrometer (GDMS) installed in a glovebox for nuclear sample screening has been employed for isotopic measurements. Isotopic compositions of zirconium, silicon, lithium, boron, uranium and plutonium which are elements of nuclear concern have been determined. Interferences arising from the matrix sample and the discharge gas (Ar) for each of these elements are discussed. The GDMS results are compared with those from thermal ionization mass spectrometry (TIMS). For boron and lithium at μg/g-ng/g levels, the two methods gave results in good agreement. In samples containing uranium the isotopic composition obtained by GDMS was in agreement with those from TIMS independently of the enrichment. Attempts for the determination of plutonium isotopic composition were also made. In this case, due to the interferences of uranium at mass 238 and americium at mass 241, the GDMS raw data are complementary with those values obtained from physical non-destructive techniques. (orig.). With 2 figs., 4 tabs

  12. Fluoride sample matrices and reaction cells — new capabilities for isotope measurements in accelerator mass spectrometry

    Directory of Open Access Journals (Sweden)

    Eliades J.

    2012-04-01

    Full Text Available Two new techniques, which extend the range of elements that can be analyzed by Accelerator Mass Spectrometry (AMS, and which increase its isobar selection capabilities, have been recently introduced. The first consists of embedding the sample material in a fluoride matrix (e.g. PbF2, which facilitates the production, in the ion source, of fluoride molecular anions that include the isotope of interest. In addition to forming anions with large electron binding energies and thereby increasing the range of analysable elements, in many cases by selection of a molecular form with a particular number of fluorine atoms, some isobar discrimination can be obtained. The second technique, for the significant reduction of atomic isobar interferences, is used following mass selection of the rare isotope. It consists of the deceleration, cooling and reaction of the rare mass beam with a gas, selected so that unwanted isobars are greatly attenuated in comparison with the isotope of interest. Proof of principle measurements for the analysis of 36C1 and 41Ca have provided encouraging results and work is proceeding on the integration of these techniques in a new AMS system planned for installation in late 2012 at the University of Ottawa.

  13. The measurement of abundance and content of 148Nd monitor for the determination of burnup with mass spectrometry

    International Nuclear Information System (INIS)

    Gao Shuqin; Li Silin

    1992-09-01

    The abundance and content of nuclide 148 Nd, which is used as monitor to determine reactor element burnup, were measured by mass spectrometry, and the burnup can be calculated from measured results. The distribution of 148 Nd abundance and content in the axial direction are consistent with the theoretical calculation. The burnup values agree with the data obtained from heavy isotope ratio and radiochemistry methods within the errors of 4.0% and 2.8% respectively

  14. Alternatives to isotope ratio mass spectrometry for the measurement of deuterium content of body water

    International Nuclear Information System (INIS)

    Bluck, L.J.C.

    2000-01-01

    The measurement of breast milk intake using the isotope dilution techniques is now well established. The methodology involves the administration of a bolus of tracer followed by observation of the kinetics of its passage though the system. For example in the popular 'dose to the mother' method a dose of labeled water is administered to the mother, and over the following days samples of body fluids are taken and the concentration of tracer determined in order to establish the rate of loss of tracer from her body. Likewise samples are taken from the breast fed infant in order to determine the rates of tracer intake and subsequent loss. Deuterium is the tracer of choice for these experiments since it is non-radioactive, and therefore suitable for use in these vulnerable subject groups, and also because of its relative cheapness. Conventionally isotope ratio mass spectrometry (IRMS) has been used for the determination of the amount of deuterium in the body fluids. However this methodology is expensive (an instrument might typically cost US$ 150,000), and it requires a considerable amount of dedicated technical expertise for its operation. Consequently such instrumentation is not widely available, and this has limited the number and scope of studies using this technique. Recently there have been reports of possible alternative technologies for the determination of deuterium in body water which appear attractive because of the wider general availability of the equipment required. It is the purpose of this report to assess these reported methods for their suitability for breast milk intake measurements

  15. Eddy covariance flux measurements of ammonia by high temperature chemical ionisation mass spectrometry

    Directory of Open Access Journals (Sweden)

    J. Sintermann

    2011-03-01

    Full Text Available A system for fast ammonia (NH3 measurements with chemical ionisation mass spectrometry (CIMS based on a commercial Proton Transfer Reaction-Mass Spectrometer (PTR-MS is presented. It uses electron transfer reaction as ionisation pathway and features a drift tube of polyetheretherketone (PEEK and silica-coated steel. Heating the instrumental inlet and the drift tube to 180 °C enabled an effective time resolution of ~1 s and made it possible to apply the instrument for eddy covariance (EC measurements. EC fluxes of NH3 were measured over two agricultural fields in Oensingen, Switzerland, following fertilisations with cattle slurry. Air was aspirated close to a sonic anemometer at a flow of 100 STP L min−1 and was directed through a 23 m long 1/2" PFA tube heated to 150 °C to an air-conditioned trailer where the gas was sub-sampled from the large bypass stream. This setup minimised damping of fast NH3 concentration changes between the sampling point and the actual measurement. High-frequency attenuation loss of the NH3 fluxes of 20 to 40% was quantified and corrected for using an empirical ogive method. The instrumental NH3 background signal showed a minor interference with H2O which was characterised in the laboratory. The resulting correction of the NH3 flux after slurry spreading was less than 1‰. The flux detection limit of the EC system was about 5 ng m−2 s−1 while the accuracy of individual flux measurements was estimated 16% for the high-flux regime during these experiments. The NH3 emissions after broad spreading of the slurry showed an initial maximum of 150 μg m−2 s−1 with a fast decline in the following hours.

  16. Use of on-ground gamma-ray spectrometry to measure plant-available potassium and other topsoil attributes

    International Nuclear Information System (INIS)

    Wong, M.T.F.; Harper, R.J.

    1999-01-01

    The incidence of potassium (K) deficiency is increasing in crops, pastures, and forestry in south-western Australia. Although soil K can be measured using soil sampling and analysis, γ-ray spectrometry offers a potentially cheaper and spatially more precise alternative. This could be particularly useful in precision agriculture, where inputs are applied according to need rather than by general prescription. In a study of topsoils near Jerramungup, Western Australia, strong relationships (r 2 = 0.9) were found between on-ground counts of γ-rays derived from 40 K (γ-K) and both total K and plant-available K. The success of γ-ray spectrometry in predicting available K relied on a strong relationship (r 2 0.9) between total K and available K which may not hold in all areas. Although the relationship between γ-K and available K held over the range of 36-1012 mg/kg, crop response to K fertilisers is only expected when the available K content is 2 = 0.9) were also found between γ-K and a range of other soil attributes, including clay, silt, and organic carbon content. These relationships depended on the locally strong relationship between total K and these soil attributes. Since such relationships do not hold everywhere, the utility of γ-ray spectrometry will likewise be limited. Site-specific calibrations are required if γ-ray spectrometry is to be used for soil property mapping. Copyright (1999) CSIRO Publishing

  17. Increasing of MERARG experimental performances: on-line fission gas release measurement by mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Pontillon, Y.; Capdevila, H.; Clement, S. [CEA, DEN, DEC, SA3C, LAMIR, F-13108 Saint Paul lez Durance, (France); Guigues, E.; Janulyte, A.; Zerega, Y.; Andre, J. [Aix-Marseille Universite, LISA EA 4672, 13397 MARSEILLE cedex 20, (France)

    2015-07-01

    The MERARG device - implemented at the LECASTAR Hot Laboratory, at the CEA Cadarache - allows characterizing nuclear fuels with respect to the behaviour of fission gases during thermal transients representative of normal or off normal operating nuclear power plant conditions. The fuel is heated in order to extract a part or the total gas inventory it contains. Fission Gas Release (FGR) is actually recorded by mean of both on-line gamma spectrometry station and micro gas chromatography. These two devices monitor the quantity and kinetics of fission gas release rate. They only address {sup 85}Kr radioactive isotope and the elemental quantification of Kr, Xe and He (with a relatively low detection limit in the latter case, typically 5-10 ppm). In order to better estimate the basic mechanisms that promote fission gas release from irradiated nuclear fuels, the CEA fuel study department decided to improve its experimental facility by modifying MERARG to extend the studies of gamma emitter fission gases to all gases (including Helium) with a complete isotopic distribution capability. To match these specifications, a Residual Gas Analyser (RGA) has been chosen as mass spectrometer. This paper presents a review of the main aspects of the qualification/calibration phase of the RGA type analyser. In particular, results recorded over three mass ranges 1-10 u, 80-90 u and 120-140 u in the two classical modes of MERARG, i.e. on-line and off-line measurements are discussed. Results obtained from a standard gas bottle show that the quantitative analysis at a few ppm levels can be achieved for all isotopes of Kr and Xe, as well as masses 2 and 4 u. (authors)

  18. Neutron spectrometry around the VENUS reactor using Monte Carlo simulations and Bonner spheres measurements

    International Nuclear Information System (INIS)

    Coeck, M.; Lacoste, V.; Muller, H.

    2005-01-01

    Full text: Reliable determination of neutron doses in workplaces is still an issue in the field of radiation protection. The EVIDOS project ('evaluation of individual dosimetry in mixed neutron and photon radiation fields', 5FP supported by the EC) aims to evaluate different methods for individual dosimetry in mixed neutron-photon workplaces in nuclear industry, and focuses on the neutron component. This objective cannot be reached on the basis of investigations in calibration fields only, but requires studies in representative workplaces of the nuclear industry. The VENUS reactor, a zero-power research reactor established by the SCK·CEN, was chosen as one of these workplaces. This paper presents the assessment of the neutron field near the VENUS reactor, particularly in areas near the reactor shielding and in the control room where operators are frequently present during a reactor run. From the neutron spectrum, an evaluation of H*(10) can be made. MCNPX simulations were performed to obtain a reference spectrum at the two areas of interest. Using a k eff calculation the source term was acquired which was subsequently used in a fixed source MCNPX model of the complete shielding geometry of the reactor hall. Reference spectrometry was also performed using a Bonner spheres system. The unfolding spectra were obtained using the NUBAY and GRAVEL codes. The NUBAY program, based on Bayesian parameter estimation methods, assumes a parameterized spectrum and provides posterior probability distributions for both the set of parameters and a set of integral quantities. The code GRAVEL, an iterative algorithm based on SAND-II, was used with various default spectra, among them the NUBAY solution. Bonner spheres data GRAVEL unfolding was also performed using the MCNPX spectra as an initial guess. In this paper the outcome of both calculations and measurements is compared. (author)

  19. A Comparison between HPGe and NaI(Tl) detectors performance for gamma-spectrometry of low level measurement

    International Nuclear Information System (INIS)

    Poursiamy, N. H.; Tajikahmadi, H.; Mirshojaei, S. F.

    2005-01-01

    According to progressive usage of nuclear technology, it's important to prevent the contamination of the environment by man-made radioisotopes and exposures of human being. Radioisotopes can enter the human body by inhalation and ingestion which are the most important ways to internal exposures. Measurement of radiation level in foodstuff is one of the most important parameters in environmental safety which is performed according to constitution and standard tests in most countries such as Iran. Gamma spectrometry is carried out by NaI(Tl) and HPGe detector systems for foodstuffs. In this research operation of HPGe and NaI(Tl) detectors in gamma spectrometry with a standard radioactive source are investigated and compared. Also the result of NaI superiority in foodstuff radiation measurement given

  20. Self-attenuation correction factors for bioindicators measured by γ spectrometry for energies <100keV

    International Nuclear Information System (INIS)

    Manduci, L.; Tenailleau, L.; Trolet, J.L.; De Vismes, A.; Lopez, G.; Piccione, M.

    2010-01-01

    The mass attenuation coefficients for a number of marine and terrestrial bioindicators were measured using γ spectrometry for energies between 22 and 80 keV. These values were then used to find the correction factor k for the apparent radioactivity. The experimental results were compared with a Monte Carlo simulation performed using PENELOPE in order to evaluate the reliability of the simplified calculation and to determine the correction factors.

  1. Measurements of natural levels of 14C in human's and rat's tissues by accelerator mass spectrometry in Korea

    International Nuclear Information System (INIS)

    Cho, S.Y.; Khu, H.J.; Kang, J.H.; Yoon, M.Y.; Kim, J.C.

    2005-01-01

    Accelerator mass spectrometry (AMS) is the most sensitive, safe and precise analytical method for quantifying long-lived isotope in biomedical research with animals as well as human beings. In Korea, AMS Laboratory has been operating successfully for years measuring especially archaeological samples for 14 C dating. In this year, a biological sample pretreatment facility was setup to work on biomedical applications. As a preliminary study, we have measured the natural background levels of 14 C in tissues and blood of humans and rats have been measured. The results were agreed with the other reported levels and gave stable and reproducible results within 1-2%. (author)

  2. The participation of ATOMKI in the G-2 international intercomparison of high precision gamma-ray spectrometry measurements

    International Nuclear Information System (INIS)

    Gaspar, A.; Lakatos, T.; Sulik, B.; Toeroek, I.

    1981-01-01

    International intercomparison had been organized by the IAEA in high precision gamma spectrometry. Five mixed-spectrum sources were prepared and sent to the participants by the IAEA for relative gamma emission rate measurements. This source type enables the whole measuring method and procedure to be tested. Measurements were carried out using two independent methods: a.) simple normalization to an additional radioactive source; b.) using a time variant pulse processor and random pulse generator for correction of dead-time and pile-up losses. The results agreed in most cases within +-1% with the IAEA results. (R.J.)

  3. An improved mass spectrometry-based measurement of NO metabolites in biological fluids.

    Science.gov (United States)

    Yang, Xingbin; Bondonno, Catherine P; Indrawan, Adeline; Hodgson, Jonathan M; Croft, Kevin D

    2013-03-01

    Assessment of NO metabolism in vivo relies on the accurate measurement of its metabolites nitrite (NO(2)(-)), nitrate (NO(3)(-)), and nitrosothiols (RSNOs) in biological fluids. We report a sensitive method to simultaneously determine NO(2)(-) and NO(3)(-) in biological matrixes. Tetraoctylammonium was used to catalyze the complete conversion of NO(2)(-) and NO(3)(-) to stable pentafluorobenzyl (PFB) derivatives directly from aqueous acetone medium before gas chromatography and negative-ion chemical ionization mass spectrometry (GC/NICI/MS). This catalyst dramatically improved the yield of PFB derivatives for NO(2)(-) (4.5 times) and NO(3)(-) (55 times) compared to noncatalyzed derivatization methods. Analysis was performed using (15)N-labeled internal standards by selected-ion monitoring at m/z 46 for fragment NO(2)(-) and m/z 47 for its isotope analogue, (15)NO(2)(-), and m/z 62 for NO(3)(-) and m/z 63 for (15)NO(3)(-). This method allowed specific detection of both PFB derivatives over a wide dynamic range with a limit of detection below 4.5 pg for NO(2)(-) and 2.5 pg for NO(3)(-). After the specific conversion of RSNOs by HgCl(2) to NO(2)(-), this GC/NICI/MS analysis was used to measure RSNOs in plasma. A further comparison with the widely used tri-iodide chemiluminescence (I(3)(-)-CL) assay indicated that the GC/MS assay validated the lower physiological RSNO and nitrite levels reported using I(3)(-)-CL detection compared with values obtained using UV-photolysis methods. Plasma levels of RSNOs determined by GC/MS and I(3)(-)-CL were well correlated (r = 0.8). The improved GC/MS method was successfully used to determine the changes in plasma, urinary, and salivary NO(2)(-) and NO(3)(-) as well as plasma RSNOs in humans after either a low-NO(3)(-) or a high-NO(3)(-) meal. Copyright © 2012 Elsevier Inc. All rights reserved.

  4. Isotope dilution mass spectrometry for nuclear material accountability measurements: dreams and reality

    International Nuclear Information System (INIS)

    Deron, S.; )

    1996-01-01

    Gravimetry, titration, coulometry and isotope dilution mass spectrometry are alternative techniques which can be used to obtain elemental assays of the desirable accuracy. The communication briefly describes the characteristics of the procedure and summarizes a wealth of experience accumulated during actual accountability verification activities

  5. Stable isotope ratio measurements on highly enriched water samples by means of laser spectrometry

    NARCIS (Netherlands)

    van Trigt, R; Kerstel, E.R.T.; Visser, GH; Meijer, H.A.J.

    2001-01-01

    We demonstrate the feasibility of using laser spectrometry (LS) to analyze isotopically highly enriched water samples (i.e., delta H-2 less than or equal to 15000 parts per thousand, delta O-18 less than or equal to 1200 parts per thousand), as often used in the biomedical doubly labeled water (DLW)

  6. Measurement of ambient aerosols in northern Mexico City by single particle mass spectrometry

    Directory of Open Access Journals (Sweden)

    R. C. Moffet

    2008-08-01

    Full Text Available Continuous ambient measurements with aerosol time-of-flight mass spectrometry (ATOFMS were made in an industrial/residential section in the northern part of Mexico City as part of the Mexico City Metropolitan Area-2006 campaign (MCMA-2006. Results are presented for the period of 15–27 March 2006. The submicron size mode contained both fresh and aged biomass burning, aged organic carbon (OC mixed with nitrate and sulfate, elemental carbon (EC, nitrogen-organic carbon, industrial metal, and inorganic NaK inorganic particles. Overall, biomass burning and aged OC particle types comprised 40% and 31%, respectively, of the submicron mode. In contrast, the supermicron mode was dominated by inorganic NaK particle types (42% which represented a mixture of dry lake bed dust and industrial NaK emissions mixed with soot. Additionally, aluminosilicate dust, transition metals, OC, and biomass burning contributed to the supermicron particles. Early morning periods (2–6 a.m. showed high fractions of inorganic particles from industrial sources in the northeast, composed of internal mixtures of Pb, Zn, EC and Cl, representing up to 73% of the particles in the 0.2–3μm size range. A unique nitrogen-containing organic carbon (NOC particle type, peaking in the early morning hours, was hypothesized to be amines from local industrial emissions based on the time series profile and back trajectory analysis. A strong dependence on wind speed and direction was observed in the single particle types that were present during different times of the day. The early morning (3:30–10 a.m. showed the greatest contributions from industrial emissions. During mid to late mornings (7–11 a.m., weak northerly winds were observed along with the most highly aged particles. Stronger winds from the south picked up in the late morning (after 11 a.m., resulting in a decrease in the concentrations of the major aged particle types and an increase in the number fraction of fresh

  7. Direct isotope ratio measurement of uranium metal by emission spectrometry on a laser-produced plasma

    International Nuclear Information System (INIS)

    Pietsch, W.; Petit, A.; Briand, A.

    1995-01-01

    The method of Optical Emission Spectrometry on a Laser-Produced Plasma (OES/LPP) at reduced pressure has been studied for the determination of the uranium isotope ratio ( 235 U/ 238 U). Spectral profiles of the investigated transition U-II 424.437 nm show the possibility to obtain an isotopic spectral resolution in a laser-produced plasma under exactly defined experimental conditions. Spectroscopic data and results are presented. (author)

  8. Measurement parameter selection for quantitative isotope dilution gas chromatography/mass spectrometry

    International Nuclear Information System (INIS)

    Colby, B.N.; Rosecrance, A.E.; Colby, M.E.

    1981-01-01

    By use of the two-isotope model of isotope dilution, selection criteria were developed for identifying optimum m/z's for quantitation of compounds by gas chromatography/mass spectrometry. In addition, it was possible to predict the optimum ratio of naturally abundant to labeled compound and to identify appropriate data reduction methods. The validity of these predictions was confirmed by using experimental GC/MS data for several organic compounds

  9. Gas Chromatography and Mass Spectrometry Measurements and Protocols for Database and Library Development Relating to Organic Species in Support of the Mars Science Laboratory

    Science.gov (United States)

    Misra, P.; Garcia, R.; Mahaffy, P. R.

    2010-04-01

    An organic contaminant database and library has been developed for use with the Sample Analysis at Mars (SAM) instrumentation utilizing laboratory-based Gas Chromatography-Mass Spectrometry measurements of pyrolyzed and baked material samples.

  10. Comparative Analysis of Mass Spectral Similarity Measures on Peak Alignment for Comprehensive Two-Dimensional Gas Chromatography Mass Spectrometry

    Science.gov (United States)

    2013-01-01

    Peak alignment is a critical procedure in mass spectrometry-based biomarker discovery in metabolomics. One of peak alignment approaches to comprehensive two-dimensional gas chromatography mass spectrometry (GC×GC-MS) data is peak matching-based alignment. A key to the peak matching-based alignment is the calculation of mass spectral similarity scores. Various mass spectral similarity measures have been developed mainly for compound identification, but the effect of these spectral similarity measures on the performance of peak matching-based alignment still remains unknown. Therefore, we selected five mass spectral similarity measures, cosine correlation, Pearson's correlation, Spearman's correlation, partial correlation, and part correlation, and examined their effects on peak alignment using two sets of experimental GC×GC-MS data. The results show that the spectral similarity measure does not affect the alignment accuracy significantly in analysis of data from less complex samples, while the partial correlation performs much better than other spectral similarity measures when analyzing experimental data acquired from complex biological samples. PMID:24151524

  11. 40 K, 137 Cs and 232 Th activities in Brazilian milk samples measured by gamma ray spectrometry

    International Nuclear Information System (INIS)

    Melquiades, Fabio L.; Appoloni, Carlos R.

    2000-01-01

    This work deals with the measurement of radioactive activities in powdered milk, with high resolution gamma-ray spectrometry, using a HPGe detector coupled to a standard electronic nuclear chain and a multichannel card of 8192 channels. Preliminary measurements were accomplished to define the kind of the system shield, the geometry of the sample recipient, the size of the sampling and the self absorption correction. It was possible to measure the radionuclides 40 K, 137 Cs and 208 Tl, whose activities were calculated according to the International Atomic Energy Agency norms. The detector efficiency was measured employing calibrated samples, prepared with IAEA certificate standards mixed with powdered milk. Tukey's average comparison test was used to check the repeatability of the measurements and the absence of significant systematic deviation. (author)

  12. The Simultaneous measurement of serum testosterone and 5α-dihydrotestosterone by gas chromatography-mass spectrometry (GC-MS).

    Science.gov (United States)

    Kannenberg, Frank; Fobker, Manfred; Schulte, Erhard; Pierściński, Grzegorz; Kelsch, Reinhard; Zitzmann, Michael; Nofer, Jerzy-Roch; Schüring, Andreas N

    2018-01-01

    Simultaneous measurement of testosterone (T) and 5α-dihydrotestosterone (DHT) is important for diagnosing androgen deficiency states and hyperandrogenism in males and females, respectively. However, immunoassays used for T and DHT determination suffer from inadequate specificity and sensitivity, while tandem mass spectrometry is expensive and demanding in use. We developed a selective gas chromatography-mass spectrometry (GC-MS) method for parallel T and DHT measurement. The assay showed a linear response up to 46.5nmol/L, intra- and interassay imprecision and inaccuracy 90% for both analytes. The limit of quantitation was 0.117nmol/L for T and 0.168nmol/L for DHT. Comparison with immunoassays revealed good agreement for T in males, but a bias in favour of immunoassays at low concentrations for T in females and DHT in both sexes. We established reference ranges for T and DHT and suggest interval partitioning for T according to age in men and menstrual cycle in women. Assay validation in a clinical setting suggests that measuring DHT or T/DHT ratio may help identify patients with polycystic ovary syndrome. We developed a selective, simple and inexpensive GC-MS method for parallel measurement of T and DHT with potential use in the clinical laboratory. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Measuring protein synthesis using metabolic ²H labeling, high-resolution mass spectrometry, and an algorithm.

    Science.gov (United States)

    Kasumov, Takhar; Ilchenko, Serguey; Li, Ling; Rachdaoui, Nadia; Sadygov, Rovshan G; Willard, Belinda; McCullough, Arthur J; Previs, Stephen

    2011-05-01

    We recently developed a method for estimating protein dynamics in vivo with heavy water ((2)H(2)O) using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) [16], and we confirmed that (2)H labeling of many hepatic free amino acids rapidly equilibrated with body water. Although this is a reliable method, it required modest sample purification and necessitated the determination of tissue-specific amino acid labeling. Another approach for quantifying protein kinetics is to measure the (2)H enrichments of body water (precursor) and protein-bound amino acid or proteolytic peptide (product) and to estimate how many copies of deuterium are incorporated into a product. In the current study, we used nanospray linear trap Fourier transform ion cyclotron resonance mass spectrometry (LTQ FT-ICR MS) to simultaneously measure the isotopic enrichment of peptides and protein-bound amino acids. A mathematical algorithm was developed to aid the data processing. The most notable improvement centers on the fact that the precursor/product labeling ratio can be obtained by measuring the labeling of water and a protein (or peptide) of interest, thereby minimizing the need to measure the amino acid labeling. As a proof of principle, we demonstrate that this approach can detect the effect of nutritional status on albumin synthesis in rats given (2)H(2)O. Copyright © 2011 Elsevier Inc. All rights reserved.

  14. Measurement of small ion beams by thermal ionisation mass spectrometry using new 1013 Ohm resistors

    International Nuclear Information System (INIS)

    Koornneef, J.M.; Bouman, C.; Schwieters, J.B.; Davies, G.R.

    2014-01-01

    Highlights: • First data are presented using 10 13 Ohm resistors connected to Faraday collectors. • 5 prototype 10 13 Ohm resistors were installed in a TRITON-Plus TIMS. • Performance was tested by measuring Sr and Nd isotope ratios on  13 Ohm resistors perform better than ion counting and 10 11 Ohm resistors. • Fourth decimal variability can be resolved for Nd isotope ratios on 10 pg samples. - Abstract: We tested 5 newly manufactured – prototype – 10 13 Ohm resistors in the feedback loop of Faraday cup amplifiers to measure small ion beams by Thermal Ionisation Mass Spectrometry (TIMS). The high Ohmic resistors installed in the TRITON Plus at the VU University Amsterdam theoretically have 10 times lower noise levels relative to the default 10 11 Ohm resistors. To investigate the precision and accuracy of analyses using these new amplifiers we measured Sr and Nd isotopes of reference standards at a range of ion currents (3.2 × 10 −16 to 1 × 10 −12 A, corresponding to intensities of 32 μV to 100 mV on a default 10 11 Ohm amplifier) and on small amounts of material (100 and 10 pg). Internal precision and external reproducibility for Sr and Nd isotope ratios are both better when collected on 10 13 compared 10 12 Ohm resistors and to the default 10 11 Ohm resistors. At an 87 Sr ion current of 3 × 10 −14 A (3 mV on a 10 11 Ohm amplifier) the internal precision (2 SE) of 87 Sr/ 86 Sr is 5 times better for 10 13 Ohm resistors compared to 10 11 Ohm resistors. The external reproducibility (2 SD) at this beam intensity is 9 times better. Multiple 100 and 10 pg Sr standards, ran to exhaustion, yielded low 87 Sr/ 86 Sr compared to the long term average (e.g. 10 pg average = 0.710083 ± 164 (n = 11) instead of 0.710244 ± 12, n = 73). The average off-set for 10 pg standards can be explained by a loading blank contribution of 1.3 pg. In contrast, Nd data on 100 pg and 10 pg samples are accurate suggesting that Nd loading blanks do not compromise the

  15. In Situ Analytical Characterization of Contaminated Sites Using Nuclear Spectrometry Techniques. Review of Methodologies and Measurements

    International Nuclear Information System (INIS)

    2017-01-01

    Past and current human activities can result in the contamination of sites by radionuclides and heavy metals. The sources of contamination are various. The most important sources for radionuclide release include global fallout from nuclear testing, nuclear and radiological accidents, waste production from nuclear facilities, and activities involving naturally occurring radioactive material (NORM). Contamination of the environment by heavy metals mainly originates from industrial applications and mineralogical background concentration. Contamination of sites by radionuclides and heavy metals can present a risk to people and the environment. Therefore, the estimation of the contamination level and the identification of the source constitute important information for the national authorities with the responsibility to protect people and the environment from adverse health effects. In situ analytical techniques based on nuclear spectrometry are important tools for the characterization of contaminated sites. Much progress has been made in the design and implementation of portable systems for efficient and effective monitoring of radioactivity and heavy metals in the environment directly on-site. Accordingly, the IAEA organized a Technical Meeting to review the current status and trends of various applications of in situ nuclear spectrometry techniques for analytical characterization of contaminated sites and to support Member States in their national environmental monitoring programmes applying portable instrumentation. This publication represents a comprehensive review of the in situ gamma ray spectrometry and field portable X ray fluorescence analysis techniques for the characterization of contaminated sites. It includes papers on the use of these techniques, which provide useful background information for conducting similar studies, in the following Member States: Argentina, Australia, Brazil, Czech Republic, Egypt, France, Greece, Hungary, Italy, Lithuania

  16. Near-optimum procedure for half-life measurement by high-resolution gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Parker, J.L.

    1989-01-01

    A near-optimum procedure for using high-resolution γ-ray spectrometry to measure the half-lives of appropriate γ-ray- emitting-nuclides is presented. Among the important points of the procedure are the employment of the reference source method for implicit correction of pileup and deadtime losses; the use of full-energy peak-area ratios as the fundamental measured quantities; and continuous, high-rate data acquisition to obtain good results in a fraction of a half-life if desired. Equations are given for estimating the precision of the computed half-lives in terms of total measurement time, number of spectral acquisitions, and the precision of peak-area ratios. Results of 169 Yb half-life measurements are given as an example of the procedure's application. 3 refs., 2 tabs

  17. Measurement of total acid number (TAN) and TAN boiling point distribution in petroleum products by electrospray ionization mass spectrometry.

    Science.gov (United States)

    Qian, Kuangnan; Edwards, Kathleen E; Dechert, Gary J; Jaffe, Stephen B; Green, Larry A; Olmstead, William N

    2008-02-01

    We report a new method for rapid measurement of total acid number (TAN) and TAN boiling point (BP) distribution for petroleum crude and products. The technology is based on negative ion electrospray ionization mass spectrometry (ESI-MS) for selective ionization of petroleum acid and quantification of acid structures and molecular weight distributions. A chip-based nanoelectrospray system enables microscale (boiling point distributions of TAN values can be calculated from the composition. The rapid measurement of TAN BP distributions by ESI is demonstrated for a series of high-TAN crudes and distillation cuts. TAN values determined by the technique agree well with those by the titration method. The distributed properties compare favorably with those measured by distillation and measurement of TAN of corresponding cuts.

  18. Electrostatic ion trap and Fourier transform measurements for high-resolution mass spectrometry

    International Nuclear Information System (INIS)

    Bhushan, K. G.; Gadkari, S. C.; Yakhmi, J. V.; Sahni, V. C.

    2007-01-01

    We report on the development of an electrostatic ion trap for high-resolution mass spectrometry. The trap works on purely electrostatic fields and hence trapping and storing of ions is not mass restrictive, unlike other techniques based on Penning, Paul, or radio frequency quadrupole ion traps. It allows simultaneous trapping and studying of multiple mass species over a large mass range. Mass spectra were recorded in ''dispersive'' and ''self-bunching'' modes of ions. Storage lifetimes of about 100 ms and mass resolving power of about 20 000 could be achieved from the fifth harmonic Fourier transform spectrum of Xe ions recorded in the self-bunching mode

  19. Evaluation of an automated assay system to measure soil radionuclides by L x-ray and gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Nyhan, J.W.; Drennon, B.J.; Crowell, J.M.

    1982-08-01

    An automated radionuclide assay system for conducting soil radioassays using L x-ray and gamma-ray spectrometry was evaluated. Wet chemistry assay procedures were shown to be considerably more time consuming than similar analyses of soil on this radionuclide assay system. The detection limits of 241 Am and plutonium were determined, as well as the reproducibility of radionuclide assay results. The L x-ray spectrometric measurements were compared with radiochemical analyses on several tuff samples. The assay system's intrinsic germanium detector was found to respond linearly to varying low concentrations of 241 Am and plutonium, both of which were easily detected in the presence of elevated concentrations of 137 Cs

  20. Nuclear energy - Waste-packages activity measurement - Part.1: high-resolution gamma spectrometry in integral mode with open geometry

    International Nuclear Information System (INIS)

    2004-01-01

    ISO 14850:2004 describes a procedure for measurements of gamma-emitting radionuclide activity in homogeneous objects such as unconditioned waste (including process waste, dismantling waste, etc.), waste conditioned in various matrices (bitumen, hydraulic binder, thermosetting resins, etc.), notably in the form of 100 L, 200 L, 400 L or 800 L drums, and test specimens or samples, (vitrified waste), and waste packaged in a container, notably technological waste. It also specifies the calibration of the gamma spectrometry chain. The gamma energies used generally range from 0,05 MeV to 3 MeV. (authors)

  1. Measurement of natural gamma radiation in building materials from Thellar of Tiruvannamalai Dist, Tamilnadu, India by gamma ray spectrometry

    International Nuclear Information System (INIS)

    Raghu, Y.; Ravisankar, R.; Chandrasekararn, A.; Vijayagopal, P.; Venkatraman, B.

    2016-01-01

    The knowledge of natural radioactivity in building materials is an important aspect of or determining the amount of public exposure because people spend most of their time (about 80%) indoors. Further, the knowledge of this radioactivity is useful in setting the standards and national guidelines in regard to the international recommendations and in assessing the associated radiation hazard. In the present work, the concentrations of natural radionuclides were measured in four types of building materials from Thellar of Tiruvannamalai district, Tamilnadu, India using gamma-ray spectrometry and associated radiological hazards are calculated

  2. Validation of methods to measure uranium isotopes using magnetic sector mass spectrometry with inductively coupled plasma source

    International Nuclear Information System (INIS)

    Hernandez M, H.; Rios L, M. J.; Romero G, E. T.

    2017-10-01

    The mass spectrometry technique with inductively coupled plasma source (Icp-Ms) has been widely used to measure isotopic ratios of elements toxic to human health. Reason for which, in this work several measurement methods for the analysis of uranium isotopes in different matrices were implemented using magnetic sector mass spectrometry with inductively coupled plasma source (Icp-SFMS). Groundwater, sediment, soil and urine were the matrices analyzed, which were supplied by intercomparison tests conducted by the IAEA and Association for the Promotion of Quality Control of Medical Biology Analysis in Radio-toxicology. The procedures used in the treatment of soil, sediment and water samples were based on US EPA methods. In the case of the urine sample, the preparation was rapid (1:20 dilution). The average of the results obtained in yield of each matrix was 94, 71, 72 and 78% for water, urine, soil and sediment respectively. In addition, the precision in terms of standard relative deviation was less than 5% and the accuracy was less than 4%. In conclusion, the Icp-SFMS is a very sensitive technique for measuring isotopes of U in different matrices. However, careful tuning is necessary, especially in the mass regions of interest 234, 235 and 238 if an external quantification is considered using natural U solutions. (Author)

  3. Comparison of in-situ gamma ray spectrometry measurements with conventional methods in determination natural and artificial nuclides in soil

    International Nuclear Information System (INIS)

    Al-Masri, M. S.; Doubal, A. W.

    2010-12-01

    Two nuclear analytical techniques (In-Situ Gamma ray spectrometry and laboratory gamma ray spectrometry) for determination of natural and artificial radionuclides in soil have been validated. The first technique depends on determination of radioactivity content of representative samples of the studied soil after laboratory preparation, while the second technique is based on direct determination of radioactivity content of soil using in-situ gamma-ray spectrometer. Analytical validation parameter such as detection limits, repeatability, reproducibility in addition to measurement uncertainties were estimated and compared for both techniques. Comparison results have shown that the determination of radioactivity in soil should apply the two techniques together where each of techniques is characterized by its low detection limit and uncertainty suitable for defined application of measurement. Radioactive isotopes in various locations were determined using the two methods by measuring 40 k, 238 U,and 137 Cs. The results showed that there are differences in attenuation factors due to soil moisture content differences; wet weight corrections should be applied when the two techniques are compared. (author)

  4. Iodine 129 measurements by gamma spectrometry in biological samples. Results in seaweeds (Fucus serratus et laminaria digitata)

    International Nuclear Information System (INIS)

    Maro, D.; Hebert, D.; Gandon, R.; Solier, L.

    1999-01-01

    A iodine selective radiochemistry method was developed to measure 129 I(period 1,57 x 10 10 7 years) by gamma spectrometry in biological samples. This method avoids using neutron activation analysis or accelerator mass spectrometry. The method is based on iodine extraction from samples in order to obtain an aqueous matrix with no attenuation agent except 127 I(stable isotope). The parallel determination of 127 I allows to correct 129 I measurements for self attenuation and also monitor seasonal changes in iodine metabolism in biological species. Measurements were performed in two seaweed species (Fucus serratus and Laminaria digitata) samples in the area of La Hague reprocessing plant discharge between January and February 1997). Samples from stations close to the point of release (Goury and Herquemoulin), showed 129 I activities around 60 Bq kg -1 dry weight in Fucus serratus and around 300 Bq kg -1 dry weight in Laminaria digitata. 300 km away from the realize point, 129 I activities were 10 Bq kg -1 dry weight in Fucus serratus and 171 Bq kg -1 dry weight in Laminaria digitata. 127 I concentrations were between 547 and 1,232 mg kg -1 dry weight in Fucus serratus and between 6,624 and 14,296 mg kg -1 dry weight in Laminaria digitata. (authors)

  5. Catch and measure-mass spectrometry-based immunoassays in biomarker research.

    Science.gov (United States)

    Weiß, Frederik; van den Berg, Bart H J; Planatscher, Hannes; Pynn, Christopher J; Joos, Thomas O; Poetz, Oliver

    2014-05-01

    Mass spectrometry-based (MS) methods are effective tools for discovering protein biomarker candidates that can differentiate between physiological and pathophysiological states. Promising candidates are validated in studies comprising large patient cohorts. Here, targeted protein analytics are used to increase sample throughput. Methods involving antibodies, such as sandwich immunoassays or Western blots, are commonly applied at this stage. Highly-specific and sensitive mass spectrometry-based immunoassays that have been established in recent years offer a suitable alternative to sandwich immunoassays for quantifying proteins. Mass Spectrometric ImmunoAssays (MSIA) and Stable Isotope Standards and Capture by Anti-Peptide Antibodies (SISCAPA/iMALDI) are two prominent types of MS-based immunoassays in which the capture is done either at the protein or the peptide level. We present an overview of these emerging types of immunoassays and discuss their suitability for the discovery and validation of protein biomarkers. This article is part of a Special Issue entitled: Biomarkers: A Proteomic Challenge. © 2013.

  6. Measuring conditions for second order X-ray Bragg-spectrometry

    International Nuclear Information System (INIS)

    Dellith, J; Scheffel, A; Wendt, M

    2014-01-01

    The KL 2,3 (α) 1,2 -lines of 19 K, the L 3 M 4,5 (α) 1,2 -lines of 48 Cd, and the M 5 N 6,7 (α) 1,2 -lines of 92 U are lines of comparable energy in the region of approximately 3 keV. In none of these cases were we able to resolve the three doublets when recording the spectra in first order Bragg spectrometry using a PET crystal as the dispersing element. For the purpose of enhancing the resolving power of the spectrometer, the three α spectra were recorded in second order reflection, thereby transferring the lines into another spectral region dominated by X-ray quanta of half the energy. In order to achieve high net peak intensities as well as a high peak-to-background ratio and, consequently, a high level of detection capability, the discriminator settings should be optimized quite carefully. In this manner, we were able to resolve the three α doublets and estimate α 2 /α 1 intensity ratios. Inexplicably, current monographs, e.g., by Goldstein et al, do not contain any indications about the rational use of high order spectrometry. Only a few rather old monographs contain some hints in this regard

  7. Decision Threshold and Detection Limit in Spectrometric Measurements. Part 1: Application to Gamma Spectrometry

    International Nuclear Information System (INIS)

    Perez, C.; Gasco, C.; Lopez, M. A.

    2010-01-01

    This report summarised the author's lecture of the advanced gamma spectrometry course organised by CIEMAT. The characteristic limits determination in gamma spectrometry generally is obtained through the programming that the trade marks offers to the client with the objective of the automatic calculation of the activity concentrations existing in a sample. In this report, the examples shown in the ISO 11929 standard are compared to the programming realised by Genie 2k for determining characteristic limits. The main difference of both is located in the uncertainty calculations due to the efficiency calibration that is considered by ISO and not by Genie 2K. Through implementation in the software developed by trade marks will be possible to introduce this uncertainty and to assimilate to the calculation done by ISO 11929. In the second part of this report will be analyzed the more complicated samples of this application as counting in a whole body counter (following ISO-28218 about Performance Criteria for radio bioassay), multiplet, overlapping, addition of several peaks for obtaining the activity concentration, etc. (Author) 19 refs.

  8. Rapid method for the sequential measurement of isotopes of Am and Pu in liquid matrices by alpha spectrometry

    International Nuclear Information System (INIS)

    Mantero Cabrera, J.

    2014-01-01

    : In radiological emergencies it's necessary a fast response from the laboratories in the quantification of certain radionuclides, in order to take decisions. In these cases, is the reaction time the key parameter to consider (without neglecting the quality of the measurement). In this work, it is shown a method for aqueous matrices that generates Pu and Am isotopes sources in one single day of work, to be measured subsequently by alpha spectrometry. The developed methodology has been validated through its application to reference samples and also taking part intercom- parison exercises, having in both cases, satisfactory results. This way, we check the validity of this fast method that let us generate in 24 hours (since the sample arrives our laboratory), one measurement with a Minimun Detectable Activity (MDA) of about 0.004Bq/L for Pu and Am isotopes in liquid matrices. [es

  9. Reactor gamma spectrometry: status

    International Nuclear Information System (INIS)

    Gold, R.; Kaiser, B.J.

    1979-01-01

    Current work is described for Compton Recoil Gamma-Ray Spectrometry including developments in experimental technique as well as recent reactor spectrometry measurements. The current status of the method is described concerning gamma spectromoetry probe design and response characteristics. Emphasis is given to gamma spectrometry work in US LWR and BR programs. Gamma spectrometry in BR environments are outlined by focussing on start-up plans for the Fast Test Reactor (FTR). Gamma spectrometry results are presented for a LWR pressure vessel mockup in the Poolside Critical Assembly (PCA) at Oak Ridge National Laboratory

  10. Optimization of measure parameters for an X- and gamma-ray spectrometry portable system

    International Nuclear Information System (INIS)

    Fernandes, Jaquiel S.; Appoloni, Carlos R.

    2008-01-01

    In order to optimize the use of a system for in situ gamma (γ)- and X-ray spectrometry composed of a 3x3x1 mm 3 Cadmium Telluride (CdTe) detector with respect to the detection of low-activity radioactive sources, a two level factorial planning was accomplished, involving three factors that could modify the system response. This planning was made with a 137 Cs punctual source, analyzing the X-ray energy line of 32 keV from 137m Ba. It was concluded that, for the system optimization, the best configuration for the involved parameters was to work with the detector at temperature of -22 o C, shaping time of 3 μs and rise time discrimination (RTD) with value 3

  11. The use of difference spectra with a filtered rolling average background in mobile gamma spectrometry measurements

    International Nuclear Information System (INIS)

    Cresswell, A.J.; Sanderson, D.C.W.

    2009-01-01

    The use of difference spectra, with a filtering of a rolling average background, as a variation of the more common rainbow plots to aid in the visual identification of radiation anomalies in mobile gamma spectrometry systems is presented. This method requires minimal assumptions about the radiation environment, and is not computationally intensive. Some case studies are presented to illustrate the method. It is shown that difference spectra produced in this manner can improve signal to background, estimate shielding or mass depth using scattered spectral components, and locate point sources. This approach could be a useful addition to the methods available for locating point sources and mapping dispersed activity in real time. Further possible developments of the procedure utilising more intelligent filters and spatial averaging of the background are identified.

  12. Microprecipitation of barium sulfate as a suitable source for measurements of 226Ra by alpha spectrometry

    International Nuclear Information System (INIS)

    Fernandez-Cata, Geyser; Isaac-Olive, Keila : E-mail. geyser@instec.cu

    2007-01-01

    One of the most hazardous radionuclides released into the environment is the uranium's daughter 226 Ra. This nuclide behaves similar to calcium, therefore is highly toxic for humans. One of the suitable methods for its determination is alpha spectrometry. This technique, however, has as main drawback the source preparation which should be infinitely thin and massless, of regular, known, and reproducible shape, smaller in area than the active area of the detector and new (no sputtering or recoil losses). Among the various ways of preparing an alpha source are the electrodeposition and microprecipitation. Radium electrodeposition is not suitable to carry out because of the high reduction potential of this element, therefore non aqueous media is required and the chemical yield is not good. Radium however can be precipitated with barium sulfate and our previous work has shown that the precipitation is selective to this element in the presence of other alpha emitters such as uranium and polonium but divalent cations are incorporated to it. At the same time, manganese dioxide also precipitates radium free of divalent cations but alpha emitters such as uranium are present as well. The objective of this work was to establish a chemical procedure for the determination of 226 Ra in natural water by alpha spectrometry. The general methodology includes a preconcentration using a non selective coprecipitation via manganese dioxide (where cations are not included but alpha emitters do). Once the manganese dioxide is filtrated, it is re-dissolved and a selective microprecipitation using barium sulphate is carried out (where the only alpha emitter is radium). Details of the procedure, separation methods, source quality and discussion of the results will be given in the paper. (Author)

  13. Study of the matrix specific mass discrimination effects during inductively coupled plasma mass spectrometry isotope ratio measurements

    International Nuclear Information System (INIS)

    Vassileva, E.; Quetel, Ch.R.

    2004-01-01

    Sample matrix related effects on mass discrimination during inductively coupled plasma mass spectrometry (ICP-MS) isotope ratio measurements have only been rarely reported. However, they can lead to errors larger than the uncertainty claimed on the ratio results when not properly taken into account or corrected for. These matrix specific affects were experienced during an Isotope Dilution Mass Spectrometry (IDMS) campaign we carried out for the certification of the Cd amount content in some food digest samples (7% acidity and salts content around 450μg g -1 ). Dilution was not possible for Cd only present at the low ng g -1 level. Up to 1% difference was observed on Cd isotope ratio results between measurements performed directly or after matrix separation. This was a significant difference considering that less than 1.5% relative combined uncertainty was eventually estimated for these IDMS measurements. Similar results could be obtained either way after the implementation of necessary corrections. The direct measurement approach associated to a correction for mass discrimination effects using the food digest sample itself (and the IUPAC table values as reference for the natural Cd isotopic composition) was preferred as it was the easiest. Consequently, the impact of matrix effects on mass discrimination during isotope ratio measurements with two types of ICP- MS (quadrupole and magnetic sector instruments) was studied for 4 elements (Li, Cu, Cd and Tl). Samples of varying salinity (up to 0.25%) and acidity (up to 7%) characteristics were prepared using isotopic certified reference materials of these elements. The long term and short-term stability, respectively reproducibility and repeatability, of the results, as well as the evolution of the difference to certified ratio values were monitored. As expected the 13 investigated isotopic ratios were all sensitive to variations in salt and acid concentrations. Our experiments also showed that simultaneous variation

  14. Simultaneous aerosol mass spectrometry and chemical ionisation mass spectrometry measurements during a biomass burning event in the UK: insights into nitrate chemistry

    Directory of Open Access Journals (Sweden)

    E. Reyes-Villegas

    2018-03-01

    Full Text Available Over the past decade, there has been an increasing interest in short-term events that negatively affect air quality such as bonfires and fireworks. High aerosol and gas concentrations generated from public bonfires or fireworks were measured in order to understand the night-time chemical processes and their atmospheric implications. Nitrogen chemistry was observed during Bonfire Night with nitrogen containing compounds in both gas and aerosol phases and further N2O5 and ClNO2 concentrations, which depleted early next morning due to photolysis of NO3 radicals and ceasing production. Particulate organic oxides of nitrogen (PONs concentrations of 2.8 µg m−3 were estimated using the m ∕ z 46 : 30 ratios from aerosol mass spectrometer (AMS measurements, according to previously published methods. Multilinear engine 2 (ME-2 source apportionment was performed to determine organic aerosol (OA concentrations from different sources after modifying the fragmentation table and it was possible to identify two PON factors representing primary (pPON_ME2 and secondary (sPON_ME2 contributions. A slight improvement in the agreement between the source apportionment of the AMS and a collocated AE-31 Aethalometer was observed after modifying the prescribed fragmentation in the AMS organic spectrum (the fragmentation table to determine PON sources, which resulted in an r2 =  0.894 between biomass burning organic aerosol (BBOA and babs_470wb compared to an r2 =  0.861 obtained without the modification. Correlations between OA sources and measurements made using time-of-flight chemical ionisation mass spectrometry with an iodide adduct ion were performed in order to determine possible gas tracers to be used in future ME-2 analyses to constrain solutions. During Bonfire Night, strong correlations (r2 were observed between BBOA and methacrylic acid (0.92, acrylic acid (0.90, nitrous acid (0.86, propionic acid, (0.85 and hydrogen cyanide (0

  15. Simultaneous aerosol mass spectrometry and chemical ionisation mass spectrometry measurements during a biomass burning event in the UK: insights into nitrate chemistry

    Science.gov (United States)

    Reyes-Villegas, Ernesto; Priestley, Michael; Ting, Yu-Chieh; Haslett, Sophie; Bannan, Thomas; Le Breton, Michael; Williams, Paul I.; Bacak, Asan; Flynn, Michael J.; Coe, Hugh; Percival, Carl; Allan, James D.

    2018-03-01

    Over the past decade, there has been an increasing interest in short-term events that negatively affect air quality such as bonfires and fireworks. High aerosol and gas concentrations generated from public bonfires or fireworks were measured in order to understand the night-time chemical processes and their atmospheric implications. Nitrogen chemistry was observed during Bonfire Night with nitrogen containing compounds in both gas and aerosol phases and further N2O5 and ClNO2 concentrations, which depleted early next morning due to photolysis of NO3 radicals and ceasing production. Particulate organic oxides of nitrogen (PONs) concentrations of 2.8 µg m-3 were estimated using the m / z 46 : 30 ratios from aerosol mass spectrometer (AMS) measurements, according to previously published methods. Multilinear engine 2 (ME-2) source apportionment was performed to determine organic aerosol (OA) concentrations from different sources after modifying the fragmentation table and it was possible to identify two PON factors representing primary (pPON_ME2) and secondary (sPON_ME2) contributions. A slight improvement in the agreement between the source apportionment of the AMS and a collocated AE-31 Aethalometer was observed after modifying the prescribed fragmentation in the AMS organic spectrum (the fragmentation table) to determine PON sources, which resulted in an r2 = 0.894 between biomass burning organic aerosol (BBOA) and babs_470wb compared to an r2 = 0.861 obtained without the modification. Correlations between OA sources and measurements made using time-of-flight chemical ionisation mass spectrometry with an iodide adduct ion were performed in order to determine possible gas tracers to be used in future ME-2 analyses to constrain solutions. During Bonfire Night, strong correlations (r2) were observed between BBOA and methacrylic acid (0.92), acrylic acid (0.90), nitrous acid (0.86), propionic acid, (0.85) and hydrogen cyanide (0.76). A series of oxygenated species

  16. Investigation of a measure of robustness in inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Makonnen, Yoseif; Beauchemin, Diane

    2015-01-01

    In industrial/commercial settings where operators often have minimal expertise in inductively coupled plasma (ICP) mass spectrometry (MS), there is a prevalent need for a response factor indicating robust plasma conditions, which is analogous to the Mg II/Mg I ratio in ICP optical emission spectrometry (OES), whereby a Mg II/Mg I ratio of 10 constitutes robust conditions. While minimizing the oxide ratio usually corresponds to robust conditions, there is no specific target value that is widely accepted as indicating robust conditions. Furthermore, tuning for low oxide ratios does not necessarily guarantee minimal matrix effects, as they really address polyatomic interferences. From experiments, conducted in parallel for both MS and OES, there were some element pairs of similar mass and very different ionization potential that were exploited for such a purpose, the rationale being that, if these elements were ionized to the same extent, then that could be indicative of a robust plasma. The Be II/Li I intensity ratio was directly related to the Mg II/Mg I ratio in OES. Moreover, the 9Be+/7Li+ ratio was inversely related to the CeO+/Ce+ and LaO+/La+ oxide ratios in MS. The effects of different matrices (i.e. 0.01-0.1 M Na) were also investigated and compared to a conventional argon plasma optimized for maximum sensitivity. The suppression effect of these matrices was significantly reduced, if not eliminated in the case of 0.01 M Na, when the 9Be+/7Li+ ratio was around 0.30 on the Varian 820 MS instrument. Moreover, a very similar ratio (0.28) increased robustness to the same extent on a completely different ICP-MS instrument (PerkinElmer NEXION). Much greater robustness was achieved using a mixed-gas plasma with nitrogen in the outer gas and either nitrogen or hydrogen as a sheathing gas, as the 9Be+/7Li+ ratio was then around 1.70. To the best of our knowledge, this is the first report on using a simple analyte intensity ratio, 9Be+/7Li+, to gauge plasma robustness.

  17. Current perspectives of 14C-isotope measurement in biomedical accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Lappin, Graham; Garner, R.Colin

    2004-01-01

    Accelerator mass spectrometry (AMS) is an extremely sensitive nuclear physics technique developed in the mid-70's for radiocarbon dating of historical artefacts. The technique centres round the use of a tandem Van de Graaff accelerator to generate the potential energy to permit separation of elemental isotopes at the single atom level. AMS was first used in the early 90's for the analysis of biological samples containing enriched 14 C for toxicology and cancer research. Since that time biomedical AMS has been used in the study of (1) metabolism of xenobiotics in animals and humans (2) pathways of drug metabolism (3) biomarkers (4) metabolism of endogenous molecules including vitamins (5) DNA and protein binding studies and (6) clinical diagnosis. A new drug development concept which relies on the ultrasensitivity of AMS known as human microdosing (Phase 0) is being used to obtain early human metabolism information of candidate drugs arising out of discovery. These various aspects of AMS are reviewed in this article and a perspective on future applications of AMS provided. (orig.)

  18. Current perspectives of 14C-isotope measurement in biomedical accelerator mass spectrometry.

    Science.gov (United States)

    Lappin, Graham; Garner, R Colin

    2004-01-01

    Accelerator mass spectrometry (AMS) is an extremely sensitive nuclear physics technique developed in the mid-70's for radiocarbon dating of historical artefacts. The technique centres round the use of a tandem Van de Graaff accelerator to generate the potential energy to permit separation of elemental isotopes at the single atom level. AMS was first used in the early 90's for the analysis of biological samples containing enriched 14C for toxicology and cancer research. Since that time biomedical AMS has been used in the study of (1) metabolism of xenobiotics in animals and humans (2) pathways of drug metabolism (3) biomarkers (4) metabolism of endogenous molecules including vitamins (5) DNA and protein binding studies and (6) clinical diagnosis. A new drug development concept which relies on the ultrasensitivity of AMS known as human microdosing (Phase 0) is being used to obtain early human metabolism information of candidate drugs arising out of discovery. These various aspects of AMS are reviewed in this article and a perspective on future applications of AMS provided.

  19. Development of a liquid chromatography tandem mass spectrometry method for iothalamate measurement to assess renal function for potential kidney donation.

    Science.gov (United States)

    Rhea, Jeanne M; Ritchie, James C; Molinaro, Ross J

    2013-05-01

    Chronic kidney disease often goes undetected due to the insensitivity of current methods to accurately assess glomerular filtration rate (GFR) in early stages of renal dysfunction. The clearance of exogenously introduced iothalamate, a commonly used radiopaque agent, is an alternative to inulin clearance for the assessment of renal function and its use in calculating GFR can serve as a screening tool for kidney transplant donors. A method was developed to measure iothalamate in plasma and urine samples by HPLC combined with electrospray positive ionization tandem mass spectrometry (MS/MS). Iothalamate is isolated from plasma by methanol extraction and urine using a quick-spin filtration approach, then monitored by multiple reaction monitoring using the hydrogen adduct mass transitions. Iohexol was used as an internal standard. Iothalamate was measured within an analytical run time of 5 min, with a lower limit of quantification of 18.75 ng/ml. The intraassay and interassay variations of the plasma and urine iothalamate assays were both calculated using the patient's urine flow rate and plasma and urine iothalamate values. Linear correlations tested by LC-MS/MS and an accepted capillary electrophoresis (CE) assay showed similar results (GFR, r=0.92, Sy/x=10.3). We developed and validated an LC-MS/MS method for quantitating iothalamate in plasma and urine to calculate GFR used for screening potential kidney donors in our hospital system. A less sensitive mass spectrometry system does not sacrifice analytical or clinical sensitivity for measuring GFR. Copyright © 2012 Elsevier B.V. All rights reserved.

  20. Simultaneous measurement of total Estradiol and Testosterone in human serum by isotope dilution liquid chromatography tandem mass spectrometry

    Science.gov (United States)

    Zhou, Hui; Wang, Yuesong; Gatcombe, Matthew; Farris, Jacob; Botelho, Julianne C.; Caudill, Samuel P.; Vesper, Hubert W.

    2017-01-01

    Reliable measurement of total testosterone and estradiol is critical for their use as biomarkers of hormone related disorders in patient care and translation research. We developed and validated a mass spectrometry method to simultaneously quantify these analytes in human serum without chemical derivatization. Serum is equilibrated with isotopic internal standards and treated with acidic buffer to release hormones from their binding proteins. Lipids are isolated and polar impurities are removed by two serial liquid-liquid extraction steps. Total testosterone and estradiol are measured using liquid chromatography tandem mass spectrometry (LC-MS/MS) in combination of positive and negative electrospray ionization modes. The method shows broad analytical measurement range for both testosterone 0.03–48.5 nM (0.75–1400 ng/dL) and estradiol 11.0–5138 pM (2.99–1400 pg/mL) and excellent agreement with certified reference materials (mean bias less than 2.1% to SRM 971, BCR 576, 577, and 578) and a high order reference method (mean bias 1.25% for testosterone and −0.84% for estradiol). The high accuracy of the method was monitored and certified by CDC Hormone Standardization (HoSt) Program for two years with mean bias −0.7% (95%CI: −1.6% to 0.2%) for testosterone and 0.1% (95%CI: −2.2% to 2.3%) for estradiol. The method precision over a 2-year period for Quality Control pools at low, medium and high concentrations was 2.7–2.9% for testosterone and 3.3–5.3% for estradiol. With the consistently excellent accuracy and precision, this method is readily applicable for high-throughput clinical and epidemiological studies. PMID:28801832

  1. Concentration of Radon Progeny in Air by Alpha Spectrometry Measurement; Medida de los descendientes del radon en aire por Espectrometria Alfa

    Energy Technology Data Exchange (ETDEWEB)

    Acena, M L; Crespo, M T

    1989-07-01

    The concentration of radon progeny in air has been determined by alpha spectrometry measurement of 214 Po and 318 Po. A known volume of air was passed through a filter, then the alpha activity was directly measured on this filter. (Author) 15 refs.

  2. [Measurement of sialic acid from lipoproteins and human plasma by liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Guo, Shoudong; Sang, Hui; Yang, Nana; Kan, Yujie; Li, Fuyu; Li, Yu; Li, Fangyuan; Qin, Shucun

    2014-11-01

    A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was established to quantify sialic acid (N-acetylneuraminic acid, NANA) from lipoproteins and human plasma. The method was used to investigate the different contents of NANA from lipoproteins between diabetic with an average age of 51.6 years and healthy participants with an average age of 50.7 years. The NANA from lipoprotein samples was hydrolyzed by acetic acid (pH = 2) at 80 °C for 2 h and analyzed by the optimized LC-MS/MS method after high speed centrifugation and filtration. The limits of detection and quantification of NANA were 7.4 and 24.5 pg, respectively. The linear range was 2.5-80 ng/mL for NANA and the correlation coefficient (R2) was more than 0.998. The levels of NANA in the plasma of type II diabetics and healthy participants were (548.3 ± 88.9) and (415.3 ± 55.5) mg/L, respectively; and the levels of NANA from very low density lipoproteins (VLDL), low density lipoproteins (LDL), and high density lipoproteins (HDL) of the type II diabetics and the healthy participants were (4.91 ± 0.19), (6.95 ± 0.28), (3.61 ± 0.22) μg/mg and (2.90 ± 0.27), (7.03 ± 0.04), (2.40 ± 0.09) μg/mg, respectively. The sialic acid levels of VLDL and HDL from the type II diabetics were markedly higher than those of the corresponding healthy participants with the similar ages (P lipoproteins, and is reproducible and time saving.

  3. Comparative and Absolute Measurements of 11 Inorganic Constituents of 38 Human Tooth Samples with Gamma-ray Spectrometry

    International Nuclear Information System (INIS)

    Samsahl, K.; Soeremark, R.

    1961-12-01

    The mean concentrations of the following elements have been simultaneously determined in normal human dentine, enamel and dental calculus with gamma-ray spectrometry; Na, P, Cl, Ca, Mn, Cu, Zn, Br, Sr, W and Au. In a typical run one sample each of dentine, enamel and dental calculus were irradiated together with standards of the elements to be determined in a thermal neutron flux of 2 x 10 12 n/cm/sec for 20 hours. The chemical elements were separated into nine groups with ion exchange technique before the subsequent gamma spectrometric measurements. One man can manage the chemical separations and take the necessary gamma spectra from a run in one day. In a few samples of dentine, enamel and dental calculus which had been irradiated in a thermal neutron flux of 7 x 10 13 n/cm/sec for one week the additional long lived trace elements were qualitatively determined Cr, Fe, Co, Rb, Ag, Sb, Cs and Ba

  4. Geochemical and radiometric surveys of Sabkhet Al-Jaboul area by investigating trace elements, radon measurements and gamma spectrometry

    International Nuclear Information System (INIS)

    Jubeli, Y.; Aissa, M.; Al-Hilal, M.

    1999-08-01

    Radiometric and geochemical surveys were carried out over various geological formations in Sabkhet Al-Jaboul and its surrounding environment for evaluating the levels of radioactivity in the area. Therefore, a number of exploration techniques were used in this study such as gamma ray spectrometry, geochemical exploration and soil radon measurements. Although the results of this survey indicate some slight variations of which might be useful to distinguish between various lithological units, most of the obtained data do not reveal any significant radiometric values that could be considered important from the exploration point of view. However, these data were successfully handled to estimate the natural background of radioactivity throughout the geological units of the region. The results also showed the importance of the sedimentary transition contact zone where the continental fresh and salt favourable geochemical environment for uranium precipitation when other fundamental geological requirements for developing such concentrations are available. (author)

  5. Neutron spectrometry with proton recoil proportional counters at the research and measurement reactor Braunschweig - status of the technique

    International Nuclear Information System (INIS)

    Knauf, K.; Wittstock, J.

    1987-07-01

    This status report is concerned with the facilities set up for neutron spectrometry at the Research and Measurement Reactor Braunschweig, based on proton recoil proportional counters. Cylindrical counters for irradiation by a neutron beam normal to the counter wire and commercial spherical counters are employed. They can be filled with hydrogen or a hydrogeneous gas up to a pressure of 1 MPa depending on their use. The filling method and the electronic pulse processing are described. The pulse analysis system includes a pulse shape discrimination branch in order to separate γ-ray induced pulses. Finally, experimental investigations with spherical counters are discussed regarding the region of proportionality and the influence of the counter voltage on the shape of the response function. (orig./HP) [de

  6. Measuring the radium quartet ({sup 228}Ra, {sup 226}Ra, {sup 224}Ra, {sup 223}Ra) in seawater samples using gamma spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Beek, P. van, E-mail: vanbeek@legos.obs-mip.f [LEGOS, Laboratoire d' Etudes en Geophysique et Oceanographie Spatiales (CNRS/CNES/IRD/UPS), Observatoire Midi Pyrenees, 14 Avenue Edouard Belin, 31400 Toulouse (France); Souhaut, M. [LEGOS, Laboratoire d' Etudes en Geophysique et Oceanographie Spatiales (CNRS/CNES/IRD/UPS), Observatoire Midi Pyrenees, 14 Avenue Edouard Belin, 31400 Toulouse (France); Reyss, J.-L. [LSCE, Laboratoire des Sciences du Climat et de l' Environnement (CNRS/CEA/UVSQ), Avenue de la Terrasse, 91198 Gif-sur-Yvette (France)

    2010-07-15

    Radium isotopes are widely used in marine studies (eg. to trace water masses, to quantify mixing processes or to study submarine groundwater discharge). While {sup 228}Ra and {sup 226}Ra are usually measured using gamma spectrometry, short-lived Ra isotopes ({sup 224}Ra and {sup 223}Ra) are usually measured using a Radium Delayed Coincidence Counter (RaDeCC). Here we show that the four radium isotopes can be analyzed using gamma spectrometry. We report {sup 226}Ra, {sup 228}Ra, {sup 224}Ra, {sup 223}Ra activities measured using low-background gamma spectrometry in standard samples, in water samples collected in the vicinity of our laboratory (La Palme and Vaccares lagoons, France) but also in seawater samples collected in the plume of the Amazon river, off French Guyana (AMANDES project). The {sup 223}Ra and {sup 224}Ra activities determined in these samples using gamma spectrometry were compared to the activities determined using RaDeCC. Activities determined using the two techniques are in good agreement. Uncertainties associated with the {sup 224}Ra activities are similar for the two techniques. RaDeCC is more sensitive for the detection of low {sup 223}Ra activities. Gamma spectrometry thus constitutes an alternate method for the determination of short-lived Ra isotopes.

  7. First multispacecraft ion measurements in and near the Earth’s magnetosphere with the identical Cluster ion spectrometry (CIS experiment

    Directory of Open Access Journals (Sweden)

    H. Rème

    2001-09-01

    Full Text Available On board the four Cluster spacecraft, the Cluster Ion Spectrometry (CIS experiment measures the full, three-dimensional ion distribution of the major magnetospheric ions (H+, He+, He++, and O+ from the thermal energies to about 40 keV/e. The experiment consists of two different instruments: a COmposition and DIstribution Function analyser (CIS1/CODIF, giving the mass per charge composition with medium (22.5° angular resolution, and a Hot Ion Analyser (CIS2/HIA, which does not offer mass resolution but has a better angular resolution (5.6° that is adequate for ion beam and solar wind measurements. Each analyser has two different sensitivities in order to increase the dynamic range. First tests of the instruments (commissioning activities were achieved from early September 2000 to mid January 2001, and the operation phase began on 1 February 2001. In this paper, first results of the CIS instruments are presented showing the high level performances and capabilities of the instruments. Good examples of data were obtained in the central plasma sheet, magnetopause crossings, magnetosheath, solar wind and cusp measurements. Observations in the auroral regions could also be obtained with the Cluster spacecraft at radial distances of 4–6 Earth radii. These results show the tremendous interest of multispacecraft measurements with identical instruments and open a new area in magnetospheric and solar wind-magnetosphere interaction physics.Key words. Magnetospheric physics (magnetopause, cusp and boundary layers; magnetopheric configuration and dynamics; solar wind - magnetosphere interactions

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

    Science.gov (United States)

    Swart, D J; Simeonsson, J B

    1999-11-01

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

  9. Real-time measurement of plutonium in air by direct-inlet surface ionization mass spectrometry. Status report

    International Nuclear Information System (INIS)

    Stoffels, J.J.

    1980-04-01

    A new technique is being developed for monitoring low-level airborne plutonium on a real-time basis. The technique is based on surface ionization mass spectrometry of airborne particles. It will be capable of measuring plutonium concentrations below the maximum permissible concentration (MPC) level. A complete mass spectrometer was designed and constructed for this purpose. Major components which were developed and made operational for the instrument include an efficient inlet for directly sampling particles in air, a wide dynamic range ion detector and a minicomputer-based ion-burst measurement system. Calibration of the direct-inlet mass spectrometer (DIMS) was initiated to establish the instrument's response to plutonium dioxide as a function of concentration and particle size. This work revealed an important problem - bouncing of particles upon impact with the ionizing filament. Particle bounce results in a significant loss of measurement sensitivity. The feasibility of using an oven ionizer to overcome the particle bounce problem has been demonstrated. A rhenium oven ionizer was designed and constructed for the purpose of trapping particles which enter via the direct inlet. High-speed particles were trapped in the oven yielding a measurement sensitivity comparable to that for particles which are preloaded. Development of the Pu DIMS can now be completed by optimizing the oven design and calibrating the instrument's performance with UO 2 and CeO 2 particles as analogs to PuO 2 particles

  10. Correcting the effects of the matrix using capture gamma-ray spectrometry: Application to measurement by Active Neutron Interrogation

    International Nuclear Information System (INIS)

    Baudry, G.

    2003-11-01

    In the field of the measurement of low masses of fissile material ( 235 U, 239 Pu, 241 Pu) in radioactive waste drums, the Active Neutron Interrogation is a non-destructive method achieving good results. It does however remain reliant upon uncertainties related to the matrix effects on interrogation and fission neutrons. The aim of this thesis is to develop a correction method able to take into account these matrix effects by quantifying the amount of absorbent materials (chlorine and hydrogen) in a 118- liter homogeneous matrix. The main idea is to use the gamma-ray spectrometry of gamma emitted by neutron captures to identify and quantify the composition of the matrix. An indicator from its chlorine content is then deduced in order to choose the calibration coefficient which best represents the real composition of the matrix. This document firstly presents the needs of control and characterization of radioactive objects, and the means used in the field of nuclear measurement. Emphases is put in particular on the Active Neutron Interrogation method. The matrices of interest are those made of light technological waste (density ≤ 0,4 g/cm 3 ) containing hydrogenated and chlorinated materials. The advantages of gamma-rays emitted by neutron captures for the determination of a chlorine content indicator of the matrices and the principles of the correction method are then explained. Measurements have been firstly realized with an existing Neutron Interrogation device (PROMETHEE 6). Such measurements have proven its inadequacy: no signal from the matrix hydrogen was detected, due to an intense signal from the polyethylene contained in some cell elements. Moreover, the matrix chlorine content appeared difficult to be measured. A new and specific device, named REGAIN and dedicated to active gamma-rays spectrometry, was defined with the Monte-Carlo N-Particle (MCNP) code. The experiments conducted with this new device made it possible to detect the hydrogen from the

  11. Certification measurement of the cadmium, copper and lead contents in rice using isotope dilution inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Vassileva, Emilia; Quetel, Christophe R.

    2004-01-01

    This paper describes the certification of the Cd, Cu and Pb amount contents in a rice material, that were used as reference values for round 19 of the international measurement evaluation programme (IMEP). The protocol developed in this study was based on isotope dilution associated to inductively coupled plasma mass spectrometry (ID-ICP-MS). A multiple spiking approach was applied to reduce significantly the number of analytical steps. For the decomposition of the sample, three different microwave assisted digestion procedures were tested and compared. The use of hydrofluoric acid was found necessary to ensure full solubilisation and complete isotopic equilibration. Estimation of the combined uncertainty attached to the measurement results was performed according to the ISO guidelines. Contributions from the correction for moisture content, sample homogeneity, procedural blank, spike impurities, spectral interferences, instrumental background and dead-time effects were evaluated. SI-traceable values with less than 2% combined uncertainty (k = 2) were obtained for Cd, Cu and Pb, respectively, (14.39 ± 0.21) x 10 -6 mol kg -1 , (44.31 ± 0.42) x 10 -6 mol kg -1 and (2.034 ± 0.034) x 10 -6 mol kg -1 . The rice powder was observed to be highly hygroscopic and a second series of isotope dilution mass spectrometry measurements was carried out on samples in equilibrium with the ambient moisture conditions ('saturated' samples). The Comite Consultatif pour la Quantite de Matiere (CCQM) requested this approach for the participation to the key comparison 24 on the same rice test material. The excellent agreement for Cd between the IMEP-19 reference value, the value submitted by the institute for reference materials and measurements (IRMM) to CCQM-K24 and the corresponding reference value obtained as the arithmetic mean from the results of the 11 participating National Measurement Institutes (less than 0.27% difference) further validated this work. Eventually, this series

  12. Measurement of electro-sprayed 238 and 239+240 plutonium isotopes using 4π-alpha spectrometry. Application to environmental samples

    International Nuclear Information System (INIS)

    Charmoille-Roblot, M.

    1999-01-01

    A new protocol for plutonium deposition using the electro-spray technique coupled with 4π-α spectrometry is proposed to improve the detection limit, shorten the counting time. In order to increase the detection efficiency, it was proposed to measure 238 and 239+240 plutonium isotopes electro-sprayed deposit simultaneously on both sides of the source support, that must be as transparent as possible to alpha-emissions, in a two-alpha detectors chamber. A radiochemical protocol was adapted to electro-spray constraints and a very thin carbon foil was selected for 4π -alpha spectrometry. The method was applied to a batch of sediment samples and gave the same results as an electrodeposited source measured using conventional alpha spectrometry with a 25 % gain on counting time and 10 % on plutonium 238 detection limit. Validation and application of the technique have been made on reference samples. (author)

  13. Measurement of ²²⁶Ra in soil from oil field: advantages of γ-ray spectrometry and application to the IAEA-448 CRM.

    Science.gov (United States)

    Ceccatelli, A; Katona, R; Kis-Benedek, G; Pitois, A

    2014-05-01

    The analytical performance of gamma-ray spectrometry for the measurement of (226)Ra in TENORM (Technically Enhanced Naturally Occurring Radioactive Material) soil was investigated by the IAEA. Fast results were obtained for characterization and certification of a new TENORM Certified Reference Material (CRM), identified as IAEA-448 (soil from oil field). The combined standard uncertainty of the gamma-ray spectrometry results is of the order of 2-3% for massic activity measurement values ranging from 16500 Bq kg(-1) to 21500 Bq kg(-1). Methodologies used for the production and certification of the IAEA-448 CRM are presented. Analytical results were confirmed by alpha spectrometry. The "t" test showed agreement between alpha and gamma results at 95% confidence level. © 2013 Published by Elsevier Ltd.

  14. Airborne radon-222 measurement by active sampling with charcoal adsorption and gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Shizuma, Kiyoshi; Wen, Xiao-qiong; Fukami, Kenji; Iwatani, Kazuo; Hamanaka, Shun-ichi

    1998-01-01

    A simple method for measuring radon concentration in air is presented. Airborne radon is adsorbed in a charcoal bed by an active air sampling. In time, the adsorbed radon comes to attain radioactive equilibrium with its short-lived progeny 214 Pb. Utilizing this fact, radon concentration is derived from γ-ray measurement of 214 Pb. This method is estimated to be capable of detecting radon concentration in air down to 0.79 Bq·m -3 . The adsorption coefficient obtained with the method is compared with what is obtainable with passive sampling. Applications of this method to indoor and outdoor radon measurements are described. (author)

  15. Aircraft-borne spectrometry - a fast method for nuclide-specific measurement of soil contamination

    International Nuclear Information System (INIS)

    Winkelmann, I.; Schweiger, M.; Thomas, M.; Endrulat, H.J.

    1991-01-01

    An airworthy gamma spectrometer system for fast and large-area, nuclide-specific measurement of the soil contamination is described. The system encompasses an ultrapure germanium detector combined with a computer-controlled multichannel analyser system. The development from the laboratory system to an industrial-scale measuring system is explained. The practical testing is explained and first results are reported, obtained from measuring flights for the nuclide-specific determination of the soil contamination in the free State of Bavaria. (orig.) [de

  16. Measurement of airborne concentrations of radon-220 daughter products by alpha-particle spectrometry

    International Nuclear Information System (INIS)

    Kerr, G.D.; Ryan, M.T.; Perdue, P.T.

    1978-01-01

    The decay of naturally occurring uranium-238 and thorium-232 produces radon-222 and radon-220 isotopes which can escape into the atmosphere. If these radon gases become concentrated in air, their daughter products may present an inhalation hazard to man. The airborne concentrations of radon-222 can usually be measured very accurately in the presence of normal airborne concentrations of radon-220 and its daughters. In contrast, the measurements of the airborne concentrations of radon-220 daughters are usually complicated by the presence of radon-222 and its daughters even at normally occurring airborne concentrations. The complications involved in these measurements can be overcome in most situations by using an alpha particle spectrometer to distinguish the activity of radon-222 daughters from that due to radon-220 daughters collected on a filter. A practical spectrometer for field measurements of alpha particle activity on a filter is discussed

  17. Accelerator-based ultrasensitive mass spectrometry

    International Nuclear Information System (INIS)

    Gove, H.E.

    1985-01-01

    This chapter describes a new mass spectrometry technique involving charged particle accelerators normally used for basic research in nuclear science. Topics considered include the limitations of conventional mass spectrometry, the limitations of the direct measurement of radioactive decay, mass spectrometry using a tandem electrostatic accelerator, mass spectrometry using a cyclotron, how accelerator mass spectrometry circumvents the limitations of conventional mass spectrometry, measurements of stable isotopes, nuclear physics and astrophysics applications, modifications to existing accelerators, descriptions of dedicated systems, and future applications

  18. New measurement capabilities of mass spectrometry in the nuclear fuel cycle

    International Nuclear Information System (INIS)

    Perrin, R.E.

    1979-01-01

    Three recent developments, when combined, have the potential for greatly improving accountability measurements in the nuclear fuel cycle. The techniques are particularly valuable when measuring the contents of vessels which are difficult to calibrate by weight or volume. Input dissolver accountability measurements, inparticular, benefit from the application of these techniques. Los Alamos Scientific Laboratory has developed the capability for isotopic analysis of U and Pu samples at the nanogram level with an accuracy of 0.1 relative %. The Central Bureau for Nuclear Materials Measurement in Geel, Belgium has developed the capability of preparing mixed, solid metal U and Pu spikes with an accuracy of better than 0.1 relative %. Idaho Nuclear Energy Laboratory and C.K. Mathews at Bhabha Atomic Research have demonstrated a technique for determining the ratio of sample size to total solution measured which is independent of both the weight and the volume of the solution being measured. The advantages and limitations of these techniques are discussed. An analytical scheme which takes advantage of the special features of these techniques is proposed. 4 refs

  19. Measurement of total and free docetaxel concentration in human plasma by ultra-performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Rigo-Bonnin, Raül; Cobo-Sacristán, Sara; Gonzalo-Diego, Núria; Colom, Helena; Muñoz-Sánchez, Carmen; Urruticoechea, Ander; Falo, Catalina; Alía, Pedro

    2016-01-05

    Docetaxel is a semi-synthetic taxane with cytotoxic anti-neoplastic activity and, currently used as anticancer agent in several types of cancer. Docetaxel is highly bound to plasma proteins, and this significantly determines its clearance and activity. Therefore, measurement of free docetaxel in plasma is pharmacologically important when pharmacokinetics is investigated. We developed and validated chromatographic methods by ultra-performance liquid chromatography-tandem mass spectrometry to measure total and free docetaxel concentration in human plasma. The final validated methods involved liquid-liquid extraction followed by dryness under nitrogen evaporation. To measure free docetaxel concentration, sample preparation was preceded by ultrafiltration. Chromatographic separation was achieved using an Acquity(®) UPLC(®) BEH™ (2.1×100 mm id, 1.7 μm) reverse-phase C18 column at a flow rate of 0.4 mL/min, using isocratic elution mode containing ammonium acetate/formic acid in water/methanol (30:70 v/v) as mobile phase. Docetaxel and its internal standard (paclitaxel) were detected by electrospray ionization mass spectrometry in positive ion multiple reaction monitoring mode using mass-to-charge (m/z) transitions of 808.3→527.0 (quantifier) and 808.3→509.0 (qualifier); and 854.3→569.0 (quantifier) and 854,3→509,0 (qualifier), respectively. The run time per sample was 3.5 min. The limits of quantification were 1,95 and 0.42 μg/L and linearity was observed between 1.95 and 1000 and 0.42-100 μg/L for total and free docetaxel, respectively. Coefficients of variation and absolute relative biases were less than 13.8% and 10.0%. Recovery values were greater than 79.4%. Evaluation of the matrix effect showed ion suppression and no carry-over was observed. The validated methods could be useful for both therapeutic drug monitoring and pharmacokinetic studies. They could be applied to daily clinical laboratory practice to measure the concentration of total and free

  20. Field GE gamma spectrometry for on site measurements of some parameters characterizing radon-222 exhalation rates from soils and covers

    International Nuclear Information System (INIS)

    Zettwoog, P.; Kobal, I.; Pineau, J.F.

    1997-01-01

    We describe a new method based on differential gamma spectrometry for on site determination of some of the parameters which are relevant for the production of radon 222 in soil gas and its transfer from soil to indoor and outdoor atmospheres. This method is investigated in the context of a 3-year Slovenian-French cooperation programme, the PROTEUS project. We are currently using a germanium detector of 100 cm 3 . The height of the 20 deg. C collimated detector above the soil surface is from 1.5 to 3 m when using a tripod. This arrangement provides results which are representative of soil areas ranging from 1 to 4 square metres. Routine measurements would require larger detector volumes. The main objective is to provide technology and methodology for an efficient mapping of zones with potential for being the source of a high level of indoor radon, eliminating the need for soil sampling followed by laboratory analysis. The feasibility of an airborne mapping laboratory flying at low altitude will be investigated. Another objective is the rapid measurement of radon profiles across covers used to reduce exhalation rates from the surface of a pile of tailings, with characterisation of the influence of humidity content of the top layer. Airborne survey would allow for measuring exhalations from surfaces of slurries not otherwise accessible. (author)

  1. High-precision measurement of variations in calcium isotope ratios in urine by multiple collector inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Morgan, J.L.L.; Gordon, G.W.; Arrua, R.C.; Skulan, J.L.; Anbar, A.D.; Bullen, T.D.

    2011-01-01

    We describe a new chemical separation method to isolate Ca from other matrix elements in biological samples, developed with the long-term goal of making high-precision measurement of natural stable Ca isotope variations a clinically applicable tool to assess bone mineral balance. A new two-column procedure utilizing HBr achieves the purity required to accurately and precisely measure two Ca isotope ratios (44Ca/42Ca and 44Ca/43Ca) on a Neptune multiple collector inductively coupled plasma mass spectrometer (MC-ICPMS) in urine. Purification requirements for Sr, Ti, and K (Ca/Sr > 10000; Ca/Ti > 10000000; and Ca/K > 10) were determined by addition of these elements to Ca standards of known isotopic composition. Accuracy was determined by (1) comparing Ca isotope results for samples and standards to published data obtained using thermal ionization mass spectrometry (TIMS), (2) adding a Ca standard of known isotopic composition to a urine sample purified of Ca, and (3) analyzing mixtures of urine samples and standards in varying proportions. The accuracy and precision of δ44/42Ca measurements of purified samples containing 25 μg of Ca can be determined with typical errors less than ±0.2‰ (2σ).

  2. Measurement of radon concentration in ground water at Saijo sake brewery by means of γ-ray spectrometry

    International Nuclear Information System (INIS)

    Takenaka, Kodai; Takatori, Hiroshi; Kojima, Yasuaki; Shizuma, Kiyoshi

    2008-01-01

    Recently, natural water such as ground water and/or spring water of various places is popular for the environmental preservation and safety of food. Measurement of the radon concentration in ground water is important for risk estimate of drinking water and whether the water can be authorized as the mineral spring (74 Bq/L). In this work, radon concentration is ground water from eight places which were utilized for Saijo sake breweries was measured by means of γ-ray spectrometry. Radon concentration in each well was measured every month for two years. The variation in the radon concentration was investigated for seasonal variation, difference between the type of well, correlations with pH, water temperature and atmospheric temperature. The results are as follows: An average value of the radon concentration was 160 Bq/L which meant most of ground water satisfies the mineral spring standard. The radon concentration of the drilling well was higher than that of the punched well. The variation in the radon concentration shows no seasonal variations, nor depends on the water temperature, the atmospheric temperature and the pH. (author)

  3. Beta spectrometry

    International Nuclear Information System (INIS)

    Dryak, P.; Zderadicka, J.; Plch, J.; Kokta, L.; Novotna, P.

    1977-01-01

    For the purpose of beta spectrometry, a semiconductor spectrometer with one Si(Li) detector cooled with liquid nitrogen was designed. Geometrical detection efficiency is about 10% 4 sr. The achieved resolution for 624 keV conversion electrons of sup(137m)Ba is 2.6 keV (FWHM). A program was written in the FORTRAN language for the correction of the deformation of the measured spectra by backscattering in the analysis of continuous beta spectra. The method permits the determination of the maximum energy of the beta spectrum with an accuracy of +-5 keV. (author)

  4. Measurement of 235U enrichment in UF6 by passive gamma spectrometry

    International Nuclear Information System (INIS)

    Sawai, Hideo; Ochiai, Ken-ichi; Kaya, Akira

    1979-01-01

    For the assay of UF 6 , a single-channel analyzer (SCA) system of a passive gamma spectrometer has been developed. Basic measuring conditions were studied: such as the effects of sample density and heterogeneity and the effects of cylinder material and wall thickness. Called ''enrichment analyzer'', the system is operated to carry out the measurement and calculation of 235 U enrichment by a directive of the program in a calculator. The resulting data are available in real time output. Measurements were carried out in two modes: ''all way'' mode which measured in the rotation of the cylinder and the up-and-down motion of the detector, and ''spot'' mode which measured at one point on the cylinder. The average accuracy was about 1.8% in case of the former, and 3.2% in case of the latter. It was shown that the ''all way'' mode is preferable, but the ''spot'' mode is also necessary for the assay of large cylinders such as 30 A type. (J.P.N.)

  5. Measurement of Muscle Protein Fractional Synthetic Rate by Capillary Gas Chromatography/Combustion Isotope Ratio Mass Spectrometry

    Science.gov (United States)

    Yarasheski, Kevin E.; Smith, Kenneth; Rennie, Michael J.; Bier, Dennis M.

    2014-01-01

    The measurement of skeletal muscle protein fractional synthetic rate using an infusion of (1-13C)leucine and measuring the isotopic abundance of the tracer in skeletal muscle protein by preparative gas chromatography (GC)/ninhydrin isotope ratio mass spectrometry (IRMS) is laborious and subject to errors owing to contamination by 12C. The purpose of this study was to compare muscle (13C)leucine enrichment measured with the conventional preparative GC/ninhydrin IRMS approach to a new, continuous-flow technique using capillary GC/combustion IRMS. Quadriceps muscles were removed from four Sprague–Dawley rats after each was infused at a different rate with (1-13C)leucine for 6–8 h. Muscle leucine enrichment (at.% excess) measured by both methods differed by less than 4%, except at low (13C)leucine enrichments (IRMS was used to assess muscle (13C)leucine enrichment and fractional muscle protein synthesis rate in ten normal young men and women infused with (1,2-13C2)leucine for 12–14 h. This approach reduced the variability of the isotope abundance measure and gave estimates of muscle protein synthesis rate (0.050 ± 0.011% h−1 (mean ± SEM); range = 0.023–0.147% h−1) that agree with published values determined using the standard analytical approach. The measurement of (13C)leucine enrichment from skeletal muscle protein by capillary GC/combustion IRMS provides a simple, acceptable and practical alternative to preparative GC/ninhydrin IRMS. PMID:1420371

  6. Real-time ultrafast dynamics of dense, hot matter measured by pump-probe Doppler spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Lad, Amit D; Mondal, S; Narayanan, V; Ahmed, Saima; Kumar, G Ravindra; Rajeev, P P; Robinson, A P L [Central Laser Facility, Rutherford-Appleton Laboratory, Chilton, Oxfordshire (United Kingdom); Pasley, J, E-mail: amitlad@tifr.res.i [Department of Physics, University of York, Heslington, York (United Kingdom)

    2010-08-01

    A detailed understanding of the critical surface motion of high intensity laser produced plasma is very crucial for understanding the interaction. We employ the two colour pump-probe technique to report the first ever femtosecond scale ultrafast dynamics measurement of the critical surface of a solid plasma produced by a relativistically intense, femtosecond pump laser beam (10{sup 18} W/cm{sup 2}, 30 fs, 800 nm) on an aluminium target. We observe the Doppler shift of a time delayed probe laser beam (10{sup 12} W/cm{sup 2}, 80 fs, 400 nm) up to delays of 30 ps. Such unravelling of dynamics has not been possible in earlier measurements, which typically used the self reflection of a powerful pump pulse. We observe time dependent red and blue shifts and measure their magnitudes to infer plasma expansion velocity and acceleration and thereby the plasma profile. Our results are very well reproduced by 1D hydrodynamic simulation (HYADES code).

  7. In-situ-gamma ray spectrometry for measurements of environmental radioactivity

    Energy Technology Data Exchange (ETDEWEB)

    Winkelmann, I

    1994-12-31

    A detailed description of the method is presented. The range of application is shown. The calibration of the in-situ gamma ray spectrometer with a HPGe semiconductor detector and the evaluation of the spectra are described. A measuring time of about 15-30 min is sufficient to determine the specific natural and man-made radioactivity of the soil of some ten Bq/m{sup 2}. The results of soil contamination measurements in Germany after the Chernobyl accident are reported. A total of 22 nuclides are detected. The measured contamination for the first days after the accident was as follows: {sup 132}Te/{sup 132}I - 100 kBq/m{sup 2}, and {sup 131}I - 70 kBq/m{sup 2}. 6 figs., 4 tabs. (orig.).

  8. Studies on the true coincidence correction in measuring filter samples by gamma spectrometry

    CERN Document Server

    Lian Qi; Chang Yong Fu; Xia Bing

    2002-01-01

    The true coincidence correction in measuring filter samples has been studied by high efficiency HPGe gamma detectors. The true coincidence correction for a specific three excited levels de-excitation case has been analyzed, and the typical analytical expressions of true coincidence correction factors have been given. According to the measured relative efficiency on the detector surface with 8 'single' energy gamma emitters and efficiency of filter samples, the peak and total efficiency surfaces are fitted. The true coincidence correction factors of sup 6 sup 0 Co and sup 1 sup 5 sup 2 Eu calculated by the efficiency surfaces agree well with experimental results

  9. Atmospheric carbonyl sulfide (OCS measured remotely by FTIR solar absorption spectrometry

    Directory of Open Access Journals (Sweden)

    G. C. Toon

    2018-02-01

    Full Text Available Atmospheric OCS abundances have been retrieved from infrared spectra measured by the Jet Propulsion Laboratory (JPL MkIV Fourier transform infra-red (FTIR spectrometer during 24 balloon flights and during nearly 1100 days of ground-based observations since 1985. Our spectral fitting approach uses broad windows to enhance the precision and robustness of the retrievals. Since OCS has a vertical profile similar in shape to that of N2O, and since tropospheric N2O is very stable, we reference the OCS observations to those of N2O, measured simultaneously in the same air mass, to remove the effects of stratospheric transport, allowing a clearer assessment of secular changes in OCS. Balloon measurements reveal less than 5 % change in stratospheric OCS amounts over the past 25 years. Ground-based measurements reveal a springtime peak of tropospheric OCS, followed by a rapid early-summer decrease, similar to the behavior of CO2. This results in a peak-to-peak seasonal cycle of 5–6 % of the total OCS column at northern mid-latitudes. In the long-term tropospheric OCS record, a 5 % decrease is seen from 1990 to 2002, followed by a 5 % increase from 2003 to 2012.

  10. Measurement of the neutron spectrum of the Big Ten critical assembly by lithium-6 spectrometry

    International Nuclear Information System (INIS)

    De Leeuw-Gierts, G.; De Leeuw, S.; Hansen, G.E.; Helmick, H.H.

    1979-01-01

    The central neutron-flux spectrum of the Los Alamos Scientific Laboratory's critical assembly, Big Ten, was measured with a 6 Li spectrometer and techniques developed at the Centre d'Etude de L'Energie Nucleaire, Mol, as part of an experimental program to establish the characteristics of Big Ten

  11. HO2 measurements at atmospheric concentrations using a chemical ionization mass spectrometry

    Science.gov (United States)

    Albrecht, S.; Novelli, A.; Hofzumahaus, A.; Kang, S.; Baker, Y.; Mentel, T. F.; Fuchs, H.

    2017-12-01

    Correct and precise measurements of atmospheric radical species are necessary for a better understanding of the oxidative capacity of the atmosphere. Due to the reactivity of radicals, and their consequent low concentrations, direct measurements of these species are particularly challenging and have been proven in the past to be affected by interfering species. Here we present a chemical ionization source coupled to an APi-HR-TOF-MS (Aerodyne Research Inc.), which has a limit of detection for HO2 radicals well below its atmospheric concentrations ( 1 x 108 molecules cm-3). The instrument was calibrated with a well-established and characterized HO2 calibration source in use for the laser induced fluorescence instrument in the Forschungszentrum Jülich. Within the source, a well characterized amount of HO2 radicals is produced after photolysis of water by a mercury lamp. In addition, several experiments were performed in the atmosphere simulation chamber SAPHIR at the Forschungszentrum Jülich to test for potential interferences. Measurements of HO2 radicals were concurrently detected by a laser induced fluorescence instrument allowing for the comparison of measurements within the two different and independent techniques for various atmospheric conditions regarding concentrations of O3, NOx and VOCs. Results from the intercomparison together with the calibration procedure of the instrument and laboratory characterization will be presented.

  12. Measurement of trace elements in KH2PO4 crystals by x-ray fluorescence spectrometry

    International Nuclear Information System (INIS)

    Ryon, R.W.; Duewer, T.I.

    1981-02-01

    A non-destructive method is described for the quantitative measurement of impurities in KDP (KH 2 PO 4 ) crystals. Part per million concentrations of impurities can be determined with good accuracy in about one hour of instrument time. An energy dispersive x-ray spectrometer is used. Both the crystals and the solutions from which they are grown may be analyzed

  13. Eddy covariance flux measurements of biogenic VOCs during ECHO 2003 using proton transfer reaction mass spectrometry

    Directory of Open Access Journals (Sweden)

    C. Spirig

    2005-01-01

    Full Text Available Within the framework of the AFO 2000 project ECHO, two PTR-MS instruments were operated in combination with sonic anemometers to determine biogenic VOC fluxes from a mixed deciduous forest site in North-Western Germany. The measurement site was characterised by a forest of inhomogeneous composition, complex canopy structure, limited extension in certain wind directions and frequent calm wind conditions during night time. The eddy covariance (EC technique was applied since it represents the most direct flux measurement approach on the canopy scale and is, therefore, least susceptible to these non-ideal conditions. A specific flux calculation method was used to account for the sequential multi-component PTR-MS measurements and allowing an individual delay time adjustment as well as a rigorous quality control based on cospectral analysis. The validated flux results are consistent with light and temperature dependent emissions of isoprene and monoterpenes from this forest, with average daytime emissions of 0.94 and 0.3µg m-2s-1, respectively. Emissions of methanol reached on average 0.087µg m-2s-1 during daytime, but fluxes were too small to be detected during night time. Upward fluxes of the isoprene oxidation products methyl vinyl ketone (MVK and methacrolein (MACR were also found, being two orders of magnitude lower than those of isoprene. Calculations with an analytical footprint model indicate that the observed isoprene fluxes correlate with the fraction of oaks within the footprints of the flux measurement.

  14. Measurement of the neutron spectrum of the Big Ten critical assembly by lithium-6 spectrometry

    International Nuclear Information System (INIS)

    Leeuw-Gierts, G. de; Leeuw, S. de

    1980-01-01

    The central neutron-flux spectrum of the Los Alamos Scientific Laboratory's critical assembly, Big Ten, was measured with a 6 Li spectrometer and techniques developed at the Centre d'Etude de l'Energie Nucleaire, Mol, as part of an experimental program to establish the characteristics of Big Ten

  15. Direct measurement of burn up monitor by Pulsed Laser Deposition (PLD) followed by Isotopic Dilution Mass Spectrometry

    International Nuclear Information System (INIS)

    Sajimol, R.; Manoravi, P.; NaIini, S.; Balasubramanian, R.; Joseph, M.

    2012-01-01

    Burn-up measurement is an important aspect in the assessment of fuel performance especially for experimental nuclear fuels. Conventional mass spectrometric technique offer the best accuracy for determination of burn-up but they suffer from the labour intensive and time consuming chemical separation procedures followed by mass spectrometric analysis. Our laboratory has reported a potential laser mass spectrometric technique with advantages of (i) direct and fast measurement of ion intensities of selected rare earth element and residual heavy element atoms to deduce burn up and (ii) adaptability to remote handling of radioactive samples. Direct quantification of burn up monitor element in fuel in the form of pellet as well as liquid was probed by pulsed laser deposition followed by Isotopic Dilution Mass Spectrometric technique (IDMS). The procedure involving laser ablation of heavy element (namely U and Pu) and fission product (Nd, La etc) from a simulated spent fuel matrix followed by isotopic dilution mass spectrometry using thermal ionization mass spectrometry (TIMS) has been presently attempted to arrive at the rare earth element to heavy element ratio to deduce burn up using the methodology described in our earlier work. The details of IDMS technique has been reviewed by Heumann et al. Accurately weighed amounts of major rare earth fission products such as Nd, La, Ce and Sm in solution form were mixed with known quantity of uranium solution (all the weights are corresponding to their fission yields and the residual heavy element atoms after a given burn up) and mixed together to attain uniformity. The solution is then dried and resulting powder was pelletized and sintered. Subsequently, the pellet was ablated with pulsed laser (8 ns, 532 nm, Nd-YAG) and the plume was deposited on a glass plate. This deposit was dissolved in minimum amount of nitric acid. A known volume of the solution was mixed with spike (for e.g., 150 Nd/ 142 Nd, 233 U/ 238 U in this study

  16. Methods of neutron spectrometry

    International Nuclear Information System (INIS)

    Doerschel, B.

    1981-01-01

    The different methods of neutron spectrometry are based on the direct measurement of neutron velocity or on the use of suitable energy-dependent interaction processes. In the latter case the measuring effect of a detector is connected with the searched neutron spectrum by an integral equation. The solution needs suitable unfolding procedures. The most important methods of neutron spectrometry are the time-of-flight method, the crystal spectrometry, the neutron spectrometry by use of elastic collisions with hydrogen nuclei, and neutron spectrometry with the aid of nuclear reactions, especially of the neutron-induced activation. The advantages and disadvantages of these methods are contrasted considering the resolution, the measurable energy range, the sensitivity, and the experimental and computational efforts. (author)

  17. Measurements of Volatile Organic Compounds Using Proton Transfer Reaction – Mass Spectrometry during the MILAGRO 2006 Campaign

    Directory of Open Access Journals (Sweden)

    E. C. Fortner

    2009-01-01

    Full Text Available Volatile organic compounds (VOCs were measured by proton transfer reaction – mass spectrometry (PTR-MS on a rooftop in the urban mixed residential and industrial area North Northeast of downtown Mexico City as part of the Megacity Initiative – Local and Global Research Observations (MILAGRO 2006 field campaign. Thirty eight individual masses were monitored during the campaign and many species were quantified including methanol, acetaldehyde, toluene, the sum of C2 benzenes, the sum of C3 benzenes, acetone, isoprene, benzene, and ethyl acetate. The VOC measurements were analyzed to gain a better understanding of the type of VOCs present in the MCMA, their diurnal patterns, and their origins. Diurnal profiles of weekday and weekend/holiday aromatic VOC concentrations showed the influence of vehicular traffic during the morning rush hours and during the afternoon hours. Plumes including elevated toluene as high as 216 parts per billion (ppb and ethyl acetate as high as 183 ppb were frequently observed during the late night and early morning hours, indicating the possibility of significant industrial sources of the two compounds in the region. Wind fields during those peak episodes revealed no specific direction for the majority of the toluene plumes but the ethyl acetate plumes arrived at the site when winds were from the Southwest or West. The PTR-MS measurements combined with other VOC measuring techniques at the field site as well as VOC measurements conducted in other areas of the Mexico City Metropolitan Area (MCMA will help to develop a better understanding of the spatial pattern of VOCs and its variability in the MCMA.

  18. Spatially-Dependent Measurements of Surface and Near-Surface Radioactive Material Using In situ Gamma Ray Spectrometry (ISGRS) For Final Status Surveys

    Energy Technology Data Exchange (ETDEWEB)

    J. A. Chapman, A. J. Boerner, E. W. Abelquist

    2006-11-15

    In-situ, high-resolution gamma-ray spectrometry (ISGRS) measurements were conducted at the Oak Ridge Institute for Science and Education (ORISE) field laboratory in Oak Ridge, Tennessee. The purpose of these tests was to provide analytical data for assessing how “fit for use” this technology is for detecting discrete particles in soil.

  19. Spatially-Dependent Measurements of Surface and Near-Surface Radioactive Material Using In situ Gamma Ray Spectrometry (ISGRS) For Final Status Surveys

    International Nuclear Information System (INIS)

    J. A. Chapman, A. J. Boerner, E. W. Abelquist

    2006-01-01

    In-situ, high-resolution gamma-ray spectrometry (ISGRS) measurements were conducted at the Oak Ridge Institute for Science and Education ORISE field laboratory in Oak Ridge, Tennessee. The purpose of these tests was to provide analytical data for assessing how 'fit for use' this technology is for detecting discrete particles in soil

  20. Ultra-high-performance liquid chromatography-tandem mass spectrometry measurement of climbazole deposition from hair care products onto artificial skin and human scalp

    NARCIS (Netherlands)

    Chen, G.; Hoptroff, M.; Fei, X.; Su, Y.; Janssen, H.-G.

    2013-01-01

    A sensitive and specific ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed and validated for the measurement of climbazole deposition from hair care products onto artificial skin and human scalp. Deuterated climbazole was used as the internal

  1. Measurement of low radioactivity in underground laboratories by means of many-dimensional spectrometry; Messung geringer Radioaktivitaet in Untertagelaboratorien mit Hilfe mehrdimensionaler Spektrometrie

    Energy Technology Data Exchange (ETDEWEB)

    Niese, Siegfried

    2008-01-15

    In this contribution beside the possibilities for the measurements in underground laboratories also the application of the many-dimensional spectrometry is considered, under which coincidence, anticoincidence, and time-resolving spectrometric are to be understood. Very extensively the interaction of cosmic radiation with matter is considered.

  2. Measuring stable isotopes of hydrogen and oxygen in ice by means of laser spectrometry : The Bolling transition in the Dye-3 (south Greenland) ice core

    NARCIS (Netherlands)

    Trigt, R. van; Meijer, H.A.J.; Sveinbjornsdottir, A.E.; Johnsen, S.J.; Kerstel, E.R.Th.

    2002-01-01

    We report on the first application of a new technique in ice-core research, based on direct absorption infrared laser spectrometry (LS), for measuring H-2 O-17 and O-18 isotope ratios. The data are used to calculate the deuterium excess d (defined as delta(2)H - 8delta(18)O) for a section of the

  3. Uranium enrichment measurement by X- and γ-ray spectrometry with the 'URADOS' process

    International Nuclear Information System (INIS)

    Morel, Jean; Etcheverry, Michel; Riazuelo, Gilles

    1998-01-01

    The methods used for the uranium enrichment measurement require in general prior instrument calibration with several standards. Thus, it is possible to avoid the constraints involved in calibration by considering the complex spectral region called XK α . This spectral region is sufficiently limited so that the variation of the detector efficiency response is small enough to facilitate a self-calibration. Processing this region is critical and requires taking into account 3 elemental images, one corresponding to 235 U, one to 238 U and one to the X-ray fluorescence induced in the sample by radiation above 100 keV. A process called 'URADOS' based on this principle has been developed. Six uranium oxide standards with different enrichments and infinite thicknesses were counted several times to test this process; other samples, some highly enriched, were also used. The results obtained are compared to the declared values. From these measurements, it has been possible to improve the photon emission probability values

  4. Measurement of natural radioactivity: Calibration and performance of a high-resolution gamma spectrometry facility

    DEFF Research Database (Denmark)

    Murray, A. S.; Helsted, L. M.; Autzen, M.

    2018-01-01

    Murray et al. (2015) described an international inter-comparison of dose rate measurements undertaken using a homogenised beach ridge sand from Jutland, Denmark. The measured concentrations for 226Ra, 232Th and 40K from different laboratories varied considerably, with relative standard deviations...... of 26% (n=8), 59% (n=23) and 15% (n=23), respectively. In contrast, the relative standard deviations observed internally within our laboratory were 9%, 11% and 7%, respectively (n=20), and in addition our mean values were consistent with the global 40K mean, but significantly different from the 232Th...... mean. These problems in both accuracy and precision have led us to examine both the long term performance of our analytical facility, and its calibration. Our approach to the preparation of new absolute 238U, 232Th and 40K standards is outlined and tested against international standards. We also report...

  5. Ultra-Performance Liquid Chromatography Tandem Mass Spectrometry Measurement of Caffeine in Caffeine-Laced Pants and in Urine and Skin of a Pants User

    OpenAIRE

    Pellegrini, Manuela; Orsi, Daniela De; Guarino, Carmine; Rotolo, Maria; Giovannandrea, Rita di; Pacifici, Roberta; Pichini, Simona

    2014-01-01

    A fast and sensitive ultra-performance liquid chromatography tandem mass spectrometry method was developed for the measurement of caffeine in caffeine-laced pants and in urine and skin of a pants user. The substance and its internal standard (N-ethylnorcotinine) were separated by reversed phase chromatography with 5 mM ammonium formate pH 3.0 and 0.3% formic acid in acetonitrile mobile phase (83:17 v/v) by isocratic elution and detected by tandem mass spectrometry operated in multiple reacti...

  6. Alpha liquid-scintillation spectrometry used for the measurement of uranium/thorium-disequilibria in soil samples

    International Nuclear Information System (INIS)

    Fueeg, B.; Tschachtli, T.; Kraehenbuehl, U.

    1997-01-01

    For the measurements of low-level radioactivity of natural samples. It is of interest to have a system with high counting efficiency. Alpha liquid-scintillation spectrometry is attractive, because it offers a 4 π geometry. Some chemical separation can be obtained using extractive scintillators. Due to quenching problems for natural samples, additional separation power is needed. A new sample preparation method was developed employing extraction chromatographic resin for measuring 238 U, 234 U, 232 Th, 230 Th, 228 Th and 226 Ra in soil samples, without using any uranium- or thorium-tracer for determining the chemical yields. This method was tested by analyzing the two different reference materials, IAEA-375, soil from Tschernobyl, as well as IAEA SDA-1, a deep-sea sediment with a high calcium content. For all analyzed radionuclides the recoveries were better than 90% with errors (confidence level of 95%) smaller than 5%. The minimal detectable concentration ranges between 0.2 and 0.8 Bq/kg, based on a one gram aliquot of sample and 80'000 seconds counting time. (orig.)

  7. A rapid liquid chromatography tandem mass spectrometry-based method for measuring propranolol on dried blood spots.

    Science.gov (United States)

    Della Bona, Maria Luisa; Malvagia, Sabrina; Villanelli, Fabio; Giocaliere, Elisa; Ombrone, Daniela; Funghini, Silvia; Filippi, Luca; Cavallaro, Giacomo; Bagnoli, Paola; Guerrini, Renzo; la Marca, Giancarlo

    2013-05-05

    Propranolol, a non-selective beta blocker drug, is used in young infants and newborns for treating several heart diseases; its pharmacokinetics has been extensively evaluated in adult patients using extrapolation to treat pediatric population. The purpose of the present study was to develop and validate a method to measure propranolol levels in dried blood spots. The analysis was performed by using liquid chromatography/tandem mass spectrometry operating in multiple reaction monitoring mode. The calibration curve in matrix was linear in the concentration range of 2.5-200 μg/L with correlation coefficient r=0.9996. Intra-day and inter-day precisions and biases were less than 8.0% (n=10) and 11.5% (n=10) respectively. The recoveries ranged from 94 to 100% and the matrix effect did not result in a severe signal suppression. Propranolol on dried blood spot showed a good stability at three different temperatures for one month. This paper describes a micromethod for measuring propranolol levels on dried blood spot, which determines a great advantage in neonates or young infants during pharmacokinetic studies because of less invasive sampling and small blood volume required. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Continuous-flow isotope ratio mass spectrometry method for carbon and hydrogen isotope measurements on atmospheric methane

    Directory of Open Access Journals (Sweden)

    M. Brass

    2010-12-01

    Full Text Available We describe a continuous-flow isotope ratio mass spectrometry (CF-IRMS technique for high-precision δD and δ13C measurements of atmospheric methane on 40 mL air samples. CH4 is separated from other air components by utilizing purely physical processes based on temperature, time and mechanical valve switching. Chemical agents are avoided. Trace amounts of interfering compounds can be separated by gas chromatography after pre-concentration of the CH4 sample. The purified sample is then either combusted to CO2 or pyrolyzed to H2 for stable isotope measurement. Apart from connecting samples and refilling liquid nitrogen as coolant the system is fully automated and allows an unobserved, continuous analysis of samples. The analytical system has been used for analysis of air samples with CH4 mixing ratios between ~100 and ~10 000 ppb, for higher mixing ratios samples usually have to be diluted.

  9. Measurement of volatile plant compounds in field ambient air by thermal desorption-gas chromatography-mass spectrometry.

    Science.gov (United States)

    Cai, Xiao-Ming; Xu, Xiu-Xiu; Bian, Lei; Luo, Zong-Xiu; Chen, Zong-Mao

    2015-12-01

    Determination of volatile plant compounds in field ambient air is important to understand chemical communication between plants and insects and will aid the development of semiochemicals from plants for pest control. In this study, a thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) method was developed to measure ultra-trace levels of volatile plant compounds in field ambient air. The desorption parameters of TD, including sorbent tube material, tube desorption temperature, desorption time, and cold trap temperature, were selected and optimized. In GC-MS analysis, the selected ion monitoring mode was used for enhanced sensitivity and selectivity. This method was sufficiently sensitive to detect part-per-trillion levels of volatile plant compounds in field ambient air. Laboratory and field evaluation revealed that the method presented high precision and accuracy. Field studies indicated that the background odor of tea plantations contained some common volatile plant compounds, such as (Z)-3-hexenol, methyl salicylate, and (E)-ocimene, at concentrations ranging from 1 to 3400 ng m(-3). In addition, the background odor in summer was more abundant in quality and quantity than in autumn. Relative to previous methods, the TD-GC-MS method is more sensitive, permitting accurate qualitative and quantitative measurements of volatile plant compounds in field ambient air.

  10. Techniques of tandem accelerator mass spectrometry and their applications to 14C measurements

    International Nuclear Information System (INIS)

    Nakamura, Toshio; Nakai, Nobuyuki; Furukawa, Michiaki

    1990-01-01

    A tandem accelerator mass spectrometer, named Tandetron was installed at Nagoya University in 1982 for 14 C measurement. The Tandetron spectrometer consists of a Cs sputter ion source to produce negative carbon ions, a Schenkel-type 2.2 MV tandem accelerator, an ion-beam analyzing apparatus with a charge-energy selector and mass spectrometer, and a heavy ion detector to identify and count 14 C 3+ ions from various background ions. The 14 C concentrations in pine needles, sampled at the Higashiyama Campus of Nagoya University, have been measured since 1984. The present article describes some of the measurements of 14 C in pine needles, focusing on the annual changes in the Δ 14 C value of atmospheric CO 2 , and on the effect upon 14 C concentrations for pine needles of a local 14 CO 2 emission from incineration of radioactive organic solvent wastes containing 14 C, at the Radioisotope Center in the Higashiyama Campus. The pine needles at some locations seemed to be influenced by local artificial CO 2 emission. The Δ 14 C values increased noticeably from 1956 to 1964 as a result of artificial 14 C produced in nuclear weapon tests. (N.K.)

  11. Near infrared spectrometry for faecal fat measurement: comparison with conventional gravimetric and titrimetric methods.

    Science.gov (United States)

    Benini, L; Caliari, S; Guidi, G C; Vaona, B; Talamini, G; Vantini, I; Scuro, L A

    1989-01-01

    This investigation was aimed at comparing a new method for measuring faecal fat excretion, carried out with a semi-automated instrument by using near infrared analysis (NIRA), with the traditional titrimetric (Van de Kamer) and gravimetric (Sobel) methods. Near infrared analysis faecal fat was assayed on the three day stool collection from 118 patients (68 chronic pancreatitis, 19 organic diseases of the gastrointestinal tract, 19 alcoholic liver disease, 12 functional gastrointestinal disorders). A strict linear correlation was found between NIRA and both the titrimetric (r = 0.928, p less than 0.0001) and the gravimetric (r = 0.971, p less than 0.0001) methods. On homogenised faeces, a mean coefficient of variation of 2.1 (SD 1.71)% was found. Before homogenisation (where a mean coefficient of variation of 7% was found) accurate results were obtained when the mean of five measurements was considered. In conclusion, the assay of faecal fat excretion by the near infrared reflessometry appears a simple, rapid and reliable method for measuring steatorrhoea. PMID:2583563

  12. Measurements of {beta} or {alpha} emitter long lived radionuclides using inductively coupled plasma mass spectrometry; Dosage a tres bas niveau de radionucleides a longue periode emetteurs {beta} ou {alpha} par spectrometrie de masse a couplage plasma inductif

    Energy Technology Data Exchange (ETDEWEB)

    Provitina, O

    1993-10-18

    The measurement of long-lived radionuclides is highly important for characterizing nuclear wastes for their later storage. The main techniques are {alpha} spectrometry, {beta} counting and {gamma} spectrometry. The large period of these isotopes leads to low specific activity needing time consuming measurements. Moreover, the radiometric techniques are often limited by problems of interferences involving several steps of pretreatments. Among these steps, the specific extraction with crown ethers is highly selective for the separation of {sup 99}Tc, {sup 129}I and {sup 135}Cs. The radiometric techniques are here replaced by inductively coupled plasma mass spectroscopy (ICP-MS) the advantages of which are: few interferences, sensitivity which does not depend on the radiologic period as compared to radiochemistry. ICP-MS can then measure {sup 237}Np in enriched uranium matrix and reduce by a factor of 4 the sample pretreatment and the duration of the analysis usually performed by {alpha} spectrometry. Another technique, electrothermal vaporization (ETV), is consequently used. Crown ether extraction-ETV-ICP-MS is employed for measuring the long lived radionuclides {sup 99}Tc and {sup 129}I. The conditions of the extraction and the parameters of the ETV and the ICP-MS are studied and optimized. The methods optimized (extraction, electrothermal vaporization) are validated in the case of {sup 99}Tc, in real samples. The spike method is required to quantify technetium, the quantification with calibration leading to bad results. The results obtained are in good agreement with the expected values. Extraction of technetium on anionic resin and its measurement by the spike method with pneumatic nebulization-ICP-MS is also performed on other samples. Measured values are also in agreement with expected values, but the method of extraction is more time consuming (half a day) than the extraction with crown ether (one hour). (author). 54 figs., 38 tabs.

  13. Improved environmental and forensics measurements using multiple ion counters in isotope ratio mass spectrometry

    International Nuclear Information System (INIS)

    Goldberg, S.A.; Richter, S.; Schwieters, H.

    2002-01-01

    Full text: A new detector system designed for isotope ratio mass spectrometers provides improved precision on measurements of samples with very low amounts ( -11 grams) of analyte. An array of continuous dynode electron multipliers has been installed on a new ThermoFinnigan MAT Triton thermal ionization mass spectrometer acquired by the New Brunswick Laboratory. These ion counters are modifications of miniaturized, commercially-available continuous dynode electron multipliers. They can be readily installed to replace individual Faraday cups in a multi-detector mass spectrometer or bundled together and located along the detector plane with a set of Faraday cups. On the New Brunswick Laboratory mass spectrometer, nine Faraday cups, one conventional discrete dynode electron multiplier, and seven miniaturized ion counters were installed. Six of the small ion counters were bundled together and positioned on the high mass side of the Low 4 Faraday cup. One additional ion counter was positioned on the low mass side of the Low 4 Faraday cup. This arrangement allows for the simultaneous measurement of all uranium (including 233 U) or plutonium (including 244 Pu) isotopes, and allows for the measurement of larger 238 U intensities on the Faraday cup if needed. Unit mass spacing of U, Pu, or other actinides is readily achieved by the use of a mass dispersion zoom lens. The advantage of multiple ion counting is the simultaneous collection of isotopes. It overcomes many of the problems such as transient signal variation in sample emission and ionization. For a given sample, multiple ion counting generates a greater number of counts for each isotope relative to single detector ion counting and provides improved counting statistics by a factor of two or more. Initial tests indicate that the multiple ion counters exhibit high counting efficiency, a dark noise of less than 10 counts per minute and typically less than 1 count per minute, and show linear response characteristics over

  14. Measurement of 14C time scale of the rings of a tree by accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Oda, Hirotaka; Furukawa, Michiaki; Yonenobu, Hitoshi; Ikeda, Akiko; Nakamura, Toshio.

    1996-01-01

    14 C time scale is different from a histrical data in order that it is calculated by assuming that the concentration of 14 C in the sample has not been changed by age. The object of this work is to make clear the errors in measurement of 14 C time scale of the ring of a tree known the tree age. The every year ring of a Hinoki in Kiso, 950 years old, was used as a sample. The most external ring is determined as 1923 years old on the basis of the dendrochronology. The rings after 1120 years were used as the samples. α-cellulose, the most stable component in the structural components of cell of tree, was prepared from each ring. About 8 mg of α-cellulose was reduced to graphite to be measured by the tandem thoron analytic meter. The results obtained showed that 14 C time scale was older than that of the histrical data in the twelfth and thirteenth century, but it was more new than that of the histrical data from the late seventeenth to the middle of eighteenth century. The results were agreement with that of Stuiver and Pearson (1933). (S.Y.)

  15. An automated measuring system based on gamma spectrometry with HPGe detectors

    International Nuclear Information System (INIS)

    Mala, Helena; Rulik, Petr; Hyza, Miroslav; Dragounova, Lenka; Helebrant, Jan; Hroznicek, Marek; Jelinek, Pavel; Zak, Jan

    2016-01-01

    An automatic system for unattended gamma spectrometric measurements of bulk samples ( “Gamma Automat”, GA) was developed by the National Radiation Protection Institute and Nuvia, Inc. as a part of a research project. The basic parts include a detection system with two HPGe detectors in the lead shielded chambers, sample changer, sample tray and a control unit. The GA enables counting in two geometries: (i) with cylindrical containers (200 ml) either one placed at the detector face or 2-6 placed around the detector or (II) with Marinelli beakers (600 ml). The shelf can accommodate 180 cylindrical containers or 54 Marinelli beakers. Samples are changed by a robotic arm. The sample data and the analysis required are passed to the GA by a matrix code (generated within the laboratory system) located on the lid of a sample container, whence the GA reads information. Spectrometric analysis is performed automatically after the counting. Current status of GA can be remotely monitored. Information about the activities of the GA, measurement completion or failures of the equipment are automatically generated and sent to a mobile phone and the operator PC. A presentation of the GA is available at https://youtu.be/1lQhfo0Fljo. (orig.)

  16. Measurement uncertainty in single, double and triple isotope dilution mass spectrometry.

    Science.gov (United States)

    Vogl, Jochen

    2012-02-15

    Triple IDMS has been applied for the first time to the quantification of element concentrations. It has been compared with single and double IDMS obtained on the same sample set in order to evaluate the advantages and disadvantages of triple IDMS over single and double IDMS as an analytical reference procedure. The measurement results of single, double and triple IDMS are indistinguishable, considering rounding due to the individual measurement uncertainties. As expected, the relative expanded uncertainties (k = 2) achieved with double IDMS (0.08%) are dramatically smaller than those obtained with single IDMS (1.4%). Triple IDMS yields the smallest relative expanded uncertainties (k = 2, 0.077%) unfortunately at the expense of a much higher workload. Nevertheless triple IDMS has the huge advantage that the isotope ratio of the spike does not need to be determined. Elements with high memory effects, highly enriched spikes or highest metrological requirements may be typical applications for triple IDMS. Copyright © 2011 John Wiley & Sons, Ltd.

  17. Airborne gamma spectrometry measurements in the context of the exercise ARM02; Aeroradiometrische Messungen im Rahmen der Uebung ARM02

    Energy Technology Data Exchange (ETDEWEB)

    Bucher, B.; Rybach, L. [ETH Zuerich (Switzerland); Schwarz, G. [Swiss Nuclear Safety Authority, Villigen (Switzerland); Baerlocher, C. [ETH Zuerich (Switzerland)

    2003-05-01

    The international exercise under the European Union project ECCOMAGS (European Coordination and Calibration of Mobile and Airborne Gamma Spectrometry) stood in the centre of the yearly airborne gamma spectrometry measurement flights which were carried out in the time of 27 -31 May 2002. The exercise was held in Southwest Scotland in the region of Dumfries and Galloway. Unfortunately due to difficulties with flight approvals for military aircrafts data could be taken in the exercise area only on the flight back to Switzerland. Immediately after returning to Switzerland the regular measurements around the nuclear power plants Beznau (KKB) and Leibstadt (KKL), around the intermediate storage facilities for radioactive waste (ZWILAG) and around the research facility Paul Scherrer Institute were performed. The flights took place in the context of the exercise ARM02 and were lead by the Swiss National Emergency Operations Centre (NAZ). Unfortunately just a few measurements in the common intercalibration areas could be taken on the flight back from the international exercise. Nevertheless comparisons of the results with those of other European teams could be made. These comparisons proved the good calibration of our equipment. On the flight back measurements were also carried out at great altitude above the sea. This data allowed to determine very well the background of the aircraft and the cosmic stripping ratios. In the context of the regular measurements in the environs of the nuclear facilities in Switzerland the areas around the nuclear power plants Beznau and Leibstadt and around the nuclear research facility Paul Scherrer Institute were measured. The results were very similar to the results of earlier measurements in the last years. The nuclear power plant Beznau couldn't be recognised on the activity maps. But the nuclear power plant Leibstadt could be identified by its direct radiation which is specific for this type of reactor (BWR). At the site of the Paul

  18. International intercomparison of dose measurements using EPR spectrometry of tooth enamel

    International Nuclear Information System (INIS)

    Wieser, A.; Chumak, V.; Pasalskaya, L.; Pavlenko, J.; Sholom, S.; Bailiff, I.; Baran, N.; Bougai, A.; Kolesnik, S.; Maksimenko, V.; Brik, A.; Matyash, M.; Scherbina, O.; Dubovsky, S.; Kirillov, V.; Minenko, V.; Finin, V.; Haskell, E.; Hayes, R.; Kenner, G.; Ivannikov, A.; Skvortsov, V.; Stepanenko, V.; Liidja, G.; Lippmaa, E.; Past, J.; Puskar, J.; Meijer, A.; Radchuk, V.; Vaher, Ue.

    1996-01-01

    Electron paramagnetic resonance (EPR) dosimetry with teeth is the only solid state dosimetry method that allows for direct measurement of the individual dose. It is considered to be a very promising tool for retrospective individual dosimetry after accidental radioactive releases. It will help to make a reliable assessment of the radiation risk. A number of laboratories are engaged in retrospective EPR dosimetry with teeth. There is consequently a need to develop a programme of intercalibration and intercomparison to check whether the results produced by different laboratories are either consistent or accurate. The Commission of the European Communities has initiated the project ECP10 entitled, Retrospective Dosimetry and Dose reconstruction. Within the joint Eu/CIS project the 1st International Intercomparison of EPR Dosimetry with Teeth' was started in 1994. Nine research laboratories were involved from Germany, Russia, Belarus, Ukraine, Estonia and USA

  19. Experimental testing of the digital multichannel analyzer for gamma spectrometry measurements

    International Nuclear Information System (INIS)

    Novkovic, D.; Nadjdjerdj, L.; Kandic, A.; Vukanac, I.; Djurasevic, M.

    2008-01-01

    The results of experimental testing of the digital multichannel analyzer which digitalizes the signal after a preamplifier are presented. The recordings of some of the characteristics of the spectrometer containing a digital MCA, such as full-peak efficiency, net-area ratio of the two peaks and the stability of the peak position, were carried out under different input counting rates, with different radioactive sources. The tested MCA has shown some excellent features, like the stability of the peak position over a long-term period and flexibility in the adjusting of optimum measurement conditions. However, the performed tests have also shown some serious and unexpected disadvantages of the digital MCA when it operates under certain circumstances, one of them having to do with the automatic tuning of live-time correction at low-input counting rates. (author)

  20. Contribution to the study of luminous sources for uranium isotope measurements by emission spectrometry

    International Nuclear Information System (INIS)

    Leichnam, J.P.; Capitini, R.

    1964-01-01

    After a brief summary of results obtained with different hollow cathode luminous sources, the reasons for which they cannot be more widely used are given: an insufficient luminosity when uranium oxides are used in the cathode hollow; the large amount of sample required when it is metallic; the impossibility of effecting a chemical purification of the sample. Electrode-less discharge tubes excited by high frequency whose qualities (luminosity, stability, rapidity of preparation starting from small amounts of sample in various chemical forms, in particular iron) satisfy the conditions laid down for the measurement of uranium 235 by interferometry are used. Tho production process for such lamps is given together with the method of excitation. Examples of recordings obtained with an interferometer of the 'HYPEAC' type and a small grating spectrometer give an idea of the spectral qualities of these sources. (authors) [fr

  1. Twenty-five new mass values from measurements performed with isochronous mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Diwisch, Marcel [Justus-Liebig-Universitaet Giessen (Germany); Knoebel, Ronja; Geissel, Hans; Plass, Wolfgang R.; Scheidenberger, Christoph [Justus-Liebig-Universitaet Giessen (Germany); GSI, Darmstadt (Germany); Patyk, Zygmunt [National Centre for Nuclear Research, NCBJ Swierk, Warszawa (Poland); Weick, Helmut [GSI, Darmstadt (Germany); Collaboration: FRS-ESR-Collaboration

    2016-07-01

    Masses of uranium fission fragments have been measured with the FRS-ESR facility at GSI. In order to increase the mass resolving power and particle identification for non-isochronous particles, Bρ-tagging was applied in one out of two experiments. A new method of data analysis, using a correlation matrix for the combined data set from the two experiments, has provided reliable experimental mass values for 25 different neutron-rich isotopes for the first time. The new masses were obtained for nuclides in the element range from Ge to Ce. The results have been compared with theoretical predictions. At the neutron shell N=82 the comparison of experimental data for tin and cadmium isotopes show both strong shell effects in agreement with spectroscopy experiments and modern shell-model calculations.

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

    Science.gov (United States)

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

    2014-01-01

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

  3. Hyperfine structure measurements of neutral iodine atom (127I) using Fourier Transform Spectrometry

    Science.gov (United States)

    Ashok, Chilukoti; Vishwakarma, S. R.; Bhatt, Himal; Ankush, B. K.; Deo, M. N.

    2018-01-01

    We report the hyperfine Structure (hfs) splitting observations of neutral iodine atom (II) in the 6000 - 10,000 cm-1 near infrared spectral region. The measurements were carried out using a high-resolution Fourier Transform Spectrometer (FTS), where an electrodeless discharge lamp (EDL), excited using microwaves, was employed as the light source and InGaAs as the light detector. A specially designed setup was used to lower the plasma temperature of the medium so as to reduce the Doppler width and consequently to increase the spectral resolution of hfs components. A total of 183 lines with hfs splitting have been observed, out of which hfs in 53 spectral lines are reported for the first time. On the basis of hfs analysis, we derived the magnetic dipole and electric quadrupole coupling constants, A and B respectively for 30 even and 30 odd energy levels and are compared with the values available in the literature. New hfs values for 5 even and 4 odd levels are also reported here for the first time.

  4. A clinical assay for the measurement of milrinone in plasma by HPLC mass spectrometry.

    Science.gov (United States)

    Chihoho, B; Sage, A B; Smolenski, R T; Vazir, A; Rose, M L; Banner, N R; Leaver, N V

    2012-05-01

    Milrinone is a bipyridine phosphodiesterase inhibitor with positive inotropic and vasodilatory effects. As interest in longer term use of intravenous therapy increases, it becomes essential to monitor its plasma concentration owing to a narrow therapeutic range, an increased half-life in renal failure and toxicity associated with high levels. A high-performance liquid chromatography (HPLC) method with mass (MS) detection using a triple quadrupole mass spectrometer is presented. The method was compared with the UV/HPLC method and validated according to current international guidelines. Coefficients of variation of less than 7.5% were obtained across the therapeutic range and 18.3% at 2.4 ng/mL, the lower limit of quantitation. Plasma from 13 cardiac surgery patients receiving standard intravenous doses of milrinone were measured. Eight patients achieved therapeutic milrinone levels within 3-4 h post start of infusion, one was borderline sub-therapeutic and four patients achieved levels that were above the upper limit of the therapeutic range and potentially toxic. This method offers high sensitivity, is rapid, easy to use and requires minimal amount of sample. We believe this method could become the reference procedure for clinical monitoring of milrinone and help to improve the safety of the use of this drug in patients with cardiac failure. Copyright © 2011 John Wiley & Sons, Ltd.

  5. Measurement of radiation levels in soil samples by γ-ray spectrometry

    International Nuclear Information System (INIS)

    Sontakke, C.V.; Thamke, A.N.; Devika, K.; Srikanth, S.; Jayachandran, N.; Chander, Harish

    2016-01-01

    The natural terrestrial gamma radiation dose rate is an important contribution to the average dose rate received by the world's population. Estimation of the radiation dose distribution is important in assessing the health risk to a population and serve as the reference in documenting changes to environmental radioactivity in soil due to anthropogenic activities. Human beings are exposed outdoors to the natural terrestrial radiation that originates predominantly from the upper 30 cm of the soil. Only radionuclides with half-lives comparable with the age of the earth or their corresponding decay products existing in terrestrial material such as 238 U, 232 Th and 40 K are of great interest. Since these radionuclides are not uniformly distributed, the knowledge of their distribution in soil and rock play an important role in radiation protection and measurement. Gamma radiation from these represents the main external source of irradiation to the human body and the concentrations of these radionuclides in soil are determined by the radioactivity of the rock and also nature of the process of the formation of the soils. Therefore, radionuclides in soil generate a significant component of the background radiation exposure to the population

  6. Mass Spectrometry Method to Measure Membrane Proteins in Dried Blood Spots for the Detection of Blood Doping Practices in Sport.

    Science.gov (United States)

    Cox, Holly D; Eichner, Daniel

    2017-09-19

    The dried blood spot (DBS) matrix has significant utility for applications in the field where venous blood collection and timely shipment of labile blood samples is difficult. Unfortunately, protein measurement in DBS is hindered by high abundance proteins and matrix interference that increases with hematocrit. We developed a DBS method to enrich for membrane proteins and remove soluble proteins and matrix interference. Following a wash in a series of buffers, the membrane proteins are digested with trypsin and quantitated by parallel reaction monitoring mass spectrometry methods. The DBS method was applied to the quantification of four cell-specific cluster of differentiation (CD) proteins used to count cells by flow cytometry, band 3 (CD233), CD71, CD45, and CD41. We demonstrate that the DBS method counts low abundance cell types such as immature reticulocytes as well as high abundance cell types such as red blood cells, white blood cells, and platelets. When tested in 82 individuals, counts obtained by the DBS method demonstrated good agreement with flow cytometry and automated hematology analyzers. Importantly, the method allows longitudinal monitoring of CD protein concentration and calculation of interindividual variation which is difficult by other methods. Interindividual variation of band 3 and CD45 was low, 6 and 8%, respectively, while variation of CD41 and CD71 was higher, 18 and 78%, respectively. Longitudinal measurement of CD71 concentration in DBS over an 8-week period demonstrated intraindividual variation 17.1-38.7%. Thus, the method may allow stable longitudinal measurement of blood parameters currently monitored to detect blood doping practices.

  7. The use of aluminum nitride to improve Aluminum-26 Accelerator Mass Spectrometry measurements and production of Radioactive Ion Beams

    Science.gov (United States)

    Janzen, Meghan S.; Galindo-Uribarri, Alfredo; Liu, Yuan; Mills, Gerald D.; Romero-Romero, Elisa; Stracener, Daniel W.

    2015-10-01

    We present results and discuss the use of aluminum nitride as a promising source material for Accelerator Mass Spectrometry (AMS) and Radioactive Ion Beams (RIBs) science applications of 26Al isotopes. The measurement of 26Al in geological samples by AMS is typically conducted on Al2O3 targets. However, Al2O3 is not an ideal source material because it does not form a prolific beam of Al- required for measuring low-levels of 26Al. Multiple samples of aluminum oxide (Al2O3), aluminum nitride (AlN), mixed Al2O3-AlN as well as aluminum fluoride (AlF3) were tested and compared using the ion source test facility and the stable ion beam (SIB) injector platform at the 25-MV tandem electrostatic accelerator at Oak Ridge National Laboratory. Negative ion currents of atomic and molecular aluminum were examined for each source material. It was found that pure AlN targets produced substantially higher beam currents than the other materials and that there was some dependence on the exposure of AlN to air. The applicability of using AlN as a source material for geological samples was explored by preparing quartz samples as Al2O3 and converting them to AlN using a carbothermal reduction technique, which involved reducing the Al2O3 with graphite powder at 1600 °C within a nitrogen atmosphere. The quartz material was successfully converted to AlN. Thus far, AlN proves to be a promising source material and could lead towards increasing the sensitivity of low-level 26Al AMS measurements. The potential of using AlN as a source material for nuclear physics is also very promising by placing 26AlN directly into a source to produce more intense radioactive beams of 26Al.

  8. Comparative and Absolute Measurements of 11 Inorganic Constituents of 38 Human Tooth Samples with Gamma-ray Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Samsahl, K [AB Atomenergi, Stockholm (Sweden); Soeremark, R [The Clinical Laboratory and the Dept. of Prosthetics of the Royal School of Dentistry, Stockholm (Sweden)

    1961-12-15

    The mean concentrations of the following elements have been simultaneously determined in normal human dentine, enamel and dental calculus with gamma-ray spectrometry; Na, P, Cl, Ca, Mn, Cu, Zn, Br, Sr, W and Au. In a typical run one sample each of dentine, enamel and dental calculus were irradiated together with standards of the elements to be determined in a thermal neutron flux of 2 x 10{sup 12} n/cm/sec for 20 hours. The chemical elements were separated into nine groups with ion exchange technique before the subsequent gamma spectrometric measurements. One man can manage the chemical separations and take the necessary gamma spectra from a run in one day. In a few samples of dentine, enamel and dental calculus which had been irradiated in a thermal neutron flux of 7 x 10{sup 13} n/cm/sec for one week the additional long lived trace elements were qualitatively determined Cr, Fe, Co, Rb, Ag, Sb, Cs and Ba.

  9. Measurement of opioid peptides with combinations of reversed phase high performance liquid chromatography, radioimmunoassay, radioreceptorassay, and mass spectrometry

    International Nuclear Information System (INIS)

    Fridland, G.H.; Desiderio, D.M.

    1987-01-01

    As the first step, RP-HPLC gradient elution is performed of a Sep-Pak treated peptide-rich fraction from a tissue extract, and the eluent is monitored by a variety of post-HPLC detectors. In an effort to maximize the structural information that can be obtained from the analysis, UV provides the analog absorption trace; receptorassay analysis (RRA) data of all fractions that are collected are used to construct the profile of opioid-receptoractive peptides; radioimmunoassay (RIA) of selected HPLC fractions at retention times corresponding to the retention time of standards, or in some special cases of all 90-fractions, provides immunoreactivity information; and fast atom bombardment mass spectrometry (FAB-MS) in two modes - corroboration of the (M + H) + of the expected peptide, or MS/MS to monitor an amino acid sequence-determining fragment ion unique to that peptide in the selected ion monitoring (SIM) mode - provides structural information. As a demonstration of the level of quantification sensitivity that can be attained by these novel MS methods, FAB-MS-MS-SIM of solutions of synthetic leucine enkephalin was sensitive to the 70 femtomole level. This paper discusses RIA versus RRA data, and recent MS measurements of peptides in human tissues. 4 references, 1 figure

  10. Online Measurement of Exhaled NO Concentration and Its Production Sites by Fast Non-equilibrium Dilution Ion Mobility Spectrometry

    Science.gov (United States)

    Peng, Liying; Jiang, Dandan; Wang, Zhenxin; Liu, Jiwei; Li, Haiyang

    2016-03-01

    Exhaled nitric oxide (NO) is one of the most promising breath markers for respiratory diseases. Its profile for exhalation and the respiratory NO production sites can provide useful information for medical disease diagnosis and therapeutic procedures. However, the high-level moisture in exhaled gas always leads to the poor selectivity and sensitivity for ion spectrometric techniques. Herein, a method based on fast non-equilibrium dilution ion mobility spectrometry (NED-IMS) was firstly proposed to directly monitor the exhaled NO profile on line. The moisture interference was eliminated by turbulently diluting the original moisture to 21% of the original with the drift gas and dilution gas. Weak enhancement was observed for humid NO response and its limit of detection at 100% relative humidity was down to 0.58 ppb. The NO concentrations at multiple exhalation flow rates were measured, while its respiratory production sites were determined by using two-compartment model (2CM) and Högman and Meriläinen algorithm (HMA). Last but not the least, the NO production sites were analyzed hourly to tentatively investigate the daily physiological process of NO. The results demonstrated the capacity of NED-IMS in the real-time analysis of exhaled NO and its production sites for clinical diagnosis and assessment.

  11. Measurement of radionuclide activities of uranium-238 series in soil samples by gamma spectrometry: case of Vinaninkarena

    International Nuclear Information System (INIS)

    Randrianantenaina, F.R.

    2017-01-01

    The aim of this work is to determine the activity level of radionuclides of uranium-238 series. Eight soil samples are collected at Rural Commune of Vinaninkarena. After obtaining secular equilibrium, these samples have been measured using gamma spectrometry system in the Nuclear Analyses and Techniques Department of INSTN-Madagascar, with HPGe detector (30 % relative efficiency) and a Genie 2000 software. Activities obtained vary from (78±2)Bq.kg -1 to (49 231 ± 415)Bq.kg -1 . Among these eight samples, three activity levels are shown. Low activity is an activity which has value lower or equal to (89±3)Bq.kg -1 . Average activity is an activity which has value between (186± 1)Bq.kg -1 and (1049 ±7)Bq.kg -1 . And high activity is an activity which has value higher or equal to (14501±209)Bq.kg -1 . According to UNSCEAR 2000, these value are all higher than the world average value which is 35 Bq.kg -1 .It is due to the localities of sampling points. The variation of the activity level depends on radionuclide concentration of uranium-238 series in the soil. [fr

  12. Determination of Pb-210 and U-238 in environment samples by direct measurement using low energy γ spectrometry

    International Nuclear Information System (INIS)

    Godoy, J.M. de; Mendonca, A.H.; Sachett, I.A.

    1985-01-01

    The determination of Pb-210 and U-238 by γ spectrometry in environmental samples was carried out using the 47 KeV (4%) line for Pb-210 and the 63 KeV (3,9%) line from Th-234 to U-238. An intrinsic Ge detector with 0,8 KeV resolution for the 60 KeV line of Am-41 was employed. The eficiency was determined by using the radionuclide water solution. The samples were measured in a cylindric geometry with 7 cm diameter and 3 cm hight with a mass ranging from 25 to 180g, depending on the density. The self absorption correction factor for each sample was determined by using an external source of Pb-210 and Am-241. The results showed good agreement with the radiochemical analysis values. The diferences were lower than 20%; the detection limit changed from sample to sample staying on the pCi/g range for the 200 minutes couting time. (Author) [pt

  13. Human Vitamin B12 Absorption and Metabolism are Measured by Accelerator Mass Spectrometry Using Specifically Labeled 14C-Cobalamin

    International Nuclear Information System (INIS)

    Carkeet, C; Dueker, S R; Lango, J; Buchholz, B A; Miller, J W; Green, R; Hammock, B D; Roth, J R; Anderson, P J

    2006-01-01

    There is need for an improved test of human ability to assimilate dietary vitamin B 12 . Assaying and understanding absorption and uptake of B 12 is important because defects can lead to hematological and neurological complications. Accelerator mass spectrometry (AMS) is uniquely suited for assessing absorption and kinetics of 14 C-labeled substances after oral ingestion because it is more sensitive than decay counting and can measure levels of carbon-14 ( 14 C) in microliter volumes of biological samples, with negligible exposure of subjects to radioactivity. The test we describe employs amounts of B 12 in the range of normal dietary intake. The B 12 used was quantitatively labeled with 14 C at one particular atom of the DMB moiety by exploiting idiosyncrasies of Salmonellametabolism. In order to grow aerobically on ethanolamine, S. entericamust be provided with either pre-formed B 12 or two of its precursors: cobinamide and dimethylbenzimidazole (DMB). When provided with 14 C-DMB specifically labeled in the C2 position, cells produced 14 C-B 12 of high specific activity (2.1 GBq/mmol, 58 mCi/mmol) and no detectable dilution of label from endogenous DMB synthesis. In a human kinetic study, a physiological dose (1.5 mg, 2.2 KBq/59 nCi) of purified 14 C-B 12 was administered and showed plasma appearance and clearance curves consistent with the predicted behavior of the pure vitamin. This method opens new avenues for study of B 12 assimilation

  14. The measurement of the isotope ratios and concentrations of zinc by thermal ionization mass spectrometry using double isotope dilution

    International Nuclear Information System (INIS)

    Deng Zhongguo

    1994-01-01

    The isotope ratios and concentrations of zinc are measured by silicagel-thermal ionization mass spectrometry using the double isotope spikers. The double isotope spikers ( 70 Zn and 67 Zn-enriched isotopes) are used to correct the isotope mass fractionation for the zinc isotope ratios, and to certify the zinc concentrations in the unknown samples. The zinc concentrations of these double isotope spikers are surveyed by a spiker made of pure (99.99%) natural zinc metal powder. The correcting factors (f a , f t and f n ) of the zinc isotope ratios in the spiked mixture, spike and unspiked samples for the isotope mass fractionation, and the spike-to-unspiked ratios (X r ) of the zinc isotope r in the spiked mixture samples can be obtained to solve the matrix equations by numerical approximation. The natural zinc isotope ratios are: 64 Zn/ 67 Zn = 11.8498, 66 Zn/ 67 Zn = 6.7977, 68 Zn/ 67 Zn = 4.5730 and 70 Zn/ 67 Zn = 0.1520. The uncertainties determined of the isotope ratios and concentrations of zinc are +- 0.16% and +-0.31%, respectively

  15. Adduction of acrylamide with biomacromolecules at environmental dose level measured by accelerator mass spectrometry (AMS)

    International Nuclear Information System (INIS)

    Xie, Q.Y.; Sun, H.F.; Liu, Y.F.; Ding, X.F.; Fu, D.P.; Liu, K.X.

    2005-01-01

    -spermatozoon DNA, as well as AA-spermatozoon head and tail adducts correlate in a linear log/log mode with that of AA-Hb or AA-SA adducts, suggesting that both AA-Hb and AA-SA adducts could serve as suitable biomarker for AA adduction with protamine, spermatozoon DNA, head and tail at environmental level. (4) Comparing the adduction level of AA on spermatozoon head with that of tail, the two parts are very close. Thus, we conclude that the quality of sperm might be impaired by the AA exposure. (5) We also noticed that at higher dose levels (> 10 μg/kg b.w.), the adduction levels increased as in the following sequence: spermatozoon DNA< SA < Hb < protamine; whereas at lower dose levels, the sequence was different: spermatozoon DNA< Hb < protamine < SA. In conclusion, the dose response of AA adduction with Hb, SA, protamine, spermatozoon DNA, head and tail at environmental dose level were measured, and a good log/log linear correlation was established. In spermatozoon, AA mainly adducts with protamine rather than DNA. The adduction on spermatozoon head, as well as spermatozoon tail, could both influence the fertility efficacy. AMS has proven again a powerful nuclear method for studying the AA adduction with biomacromolecules, particularly at a human relevant dose level.

  16. On-line mass spectrometry measurement of fission gas release from nuclear fuel submitted to thermal transients

    International Nuclear Information System (INIS)

    Guigues, E.; Janulyte, A.; Zerega, Y.; Pontillon, Y.

    2013-06-01

    The work presented in this paper has been performed in the framework of a joint research program between Aix-Marseille University and CEA Cadarache. The aim is to develop a mass spectrometer (MS) device for the MERARG facility. MERARG is devoted to the study of fission gas release measurement, from nuclear fuels submitted to annealing tests in high activity laboratory such as LECA-STAR, thanks to gamma spectrometry. The mass spectrometer will then extend the measurement capability from the γ-emitters gases to all the gases involved in the release in order to have a better understanding of the fission gas release dynamics from fuel during thermal transients. Furthermore, the mass spectrometer instrument combines the capabilities and performances of both on-line (for release kinetic) and off-line implementations (for delayed accurate analysis of capacities containing total release gas). The paper deals with two main axes: (1) the modelling of gas sampling inlet device and its performance and (2) the first MS qualification/calibration results. The inlet device samples the gas and also adapts the pressure between MERARG sweeping line at 1.2 bar and mass spectrometer chamber at high vacuum. It is a two-stage device comprising a capillary at inlet, an intermediate vacuum chamber, a molecular leak inlet and a two-stage pumping device. Pressure drops, conductance and throughputs are estimated both for mass spectrometer operation and for exhaust gas recovery. Possible gas segregation is also estimated and device modification is proposed to attain a more accurate calibration. First experimental results obtained from a standard gas bottle show that the quantitative analysis at a few ppm level can be achieved for all isotopes of Kr and Xe, as well as masses 2 and 4 u. (authors)

  17. Boron concentration measurements by alpha spectrometry and quantitative neutron autoradiography in cells and tissues treated with different boronated formulations and administration protocols

    International Nuclear Information System (INIS)

    Bortolussi, Silva; Ciani, Laura; Postuma, Ian; Protti, Nicoletta; Luca Reversi,; Bruschi, Piero; Ferrari, Cinzia; Cansolino, Laura; Panza, Luigi; Ristori, Sandra; Altieri, Saverio

    2014-01-01

    The possibility to measure boron concentration with high precision in tissues that will be irradiated represents a fundamental step for a safe and effective BNCT treatment. In Pavia, two techniques have been used for this purpose, a quantitative method based on charged particles spectrometry and a boron biodistribution imaging based on neutron autoradiography. A quantitative method to determine boron concentration by neutron autoradiography has been recently set-up and calibrated for the measurement of biological samples, both solid and liquid, in the frame of the feasibility study of BNCT. This technique was calibrated and the obtained results were cross checked with those of α spectrometry, in order to validate them. The comparisons were performed using tissues taken form animals treated with different boron administration protocols. Subsequently the quantitative neutron autoradiography was employed to measure osteosarcoma cell samples treated with BPA and with new boronated formulations. - Highlights: • A method for 10B measurements in samples based on neutron autoradiography was developed. • The results were compared with those of alpha spectrometry applied on tissue and cell samples. • Boronated liposomes were developed and administered to osteosarcoma cell cultures. • Neutron autoradiography was employed to measure boron concentration due to liposomes. • Liposomes were proved to be more effective in concentrating boron in cells than BPA

  18. Comparison of different mass spectrometry techniques in the measurement of L-[ring-13C6]phenylalanine incorporation into mixed muscle proteins

    Science.gov (United States)

    Zabielski, Piotr; Ford, G. Charles; Persson, X. Mai; Jaleel, Abdul; Dewey, Jerry D.; Nair, K Sreekumaran

    2013-01-01

    Precise measurement of low enrichment of stable isotope labeled amino-acid tracers in tissue samples is a prerequisite in measuring tissue protein synthesis rates. The challenge of this analysis is augmented when small sample size is a critical factor. Muscle samples from human participants following an 8 hour intravenous infusion of L-[ring-13C6]phenylalanine and a bolus dose of L-[ring-13C6]phenylalanine in a mouse were utilized. Liquid Chromatography tandem mass spectrometry (LC/MS/MS), Gas Chromatography tandem mass spectrometry (GC/MS/MS) and Gas Chromatography/Mass spectrometry (GC/MS) were compared to the Gas Chromatography-Combustion-Isotope Ratio mass spectrometry (GC/C/IRMS), to measure mixed muscle protein enrichment of [ring13C6]phenylalanine enrichment. The sample isotope enrichment ranged from 0.0091 to 0.1312 Molar Percent excess (MPE). As compared with GC/C/IRMS, LC/MS/MS, GC/MS/MS and GC/MS showed coefficients of determination of R2 = 0.9962 and R2 = 0.9942, and 0.9217 respectively. However, the precision of measurements (coefficients of variation) for intra-assay are 13.0%, 1.7%, 6.3% and 13.5% and for inter-assay are 9.2%, 3.2%, 10.2% and 25% for GC/C/IRMS, LC/MS/MS, GC/MS/MS and GC/MS respectively. The muscle sample sizes required to obtain these results were 8μg, 0.8μg, 3μg and 3μg for GC/C/IRMS, LC/MS/MS, GC/MS/MS, and GC/MS respectively. We conclude that LC/MS/MS is optimally suited for precise measurements of L-[ring-13C6]phenylalanine tracer enrichment in low abundance and in small quantity samples. PMID:23378099

  19. Measurement of nitrophenols in rain and air by two-dimensional liquid chromatography-chemically active liquid core waveguide spectrometry.

    Science.gov (United States)

    Ganranoo, Lucksagoon; Mishra, Santosh K; Azad, Abul K; Shigihara, Ado; Dasgupta, Purnendu K; Breitbach, Zachary S; Armstrong, Daniel W; Grudpan, Kate; Rappenglueck, Bernhard

    2010-07-01

    We report a novel system to analyze atmospheric nitrophenols (NPs). Rain or air sample extracts (1 mL) are preconcentrated on a narrow bore (2 mm) aliphatic anion exchanger. In the absence of strong retention of NPs exhibited by aromatic ion exchangers, retained NPs are eluted as a plug by injection of 100 microL of 0.1 M Na(2)SO(4) on to a short (2 x 50 mm) reverse phase C-18 column packed with 2.2 mum particles. The salt plug passes through the C-18 column unretained while the NPs are separated by an ammonium acetate buffered methanol-water eluent, compatible with mass spectrometry (MS). The eluted NPs are measured with a long path Teflon AF-based liquid core waveguide (0.15 x 1420 mm) illuminated by a 403 nm light emitting diode and detected by a monolithic photodiode-operational amplifier. The waveguide is rendered chemically active by suspending it over concentrated ammonia that permeates into the lumen. The NPs ionize to the yellow anion form (lambda(max) approximately 400 nm). The separation of 4-nitrophenol, 2,4-dinitrophenol, 2-methyl-4-nitrophenol, 3-methyl-4-nitrophenol, and 2-nitrophenol (these are the dominant NPs, typically in that order, in both rain and air of Houston and Arlington, TX, confirmed by tandem MS) takes just over 5 min with respective S/N = 3 limits of detection (LODs) of 60, 12, 30, 67, and 23 pg/mL compared to MS/MS LODs of 20, 49, 11, 20, and 210 pg/mL. Illustrative air and rain data are presented.

  20. Broadband non-selective excitation of plutonium isotopes for isotope ratio measurements in resonance ionization mass spectrometry: a theoretical study.

    Science.gov (United States)

    Sankari, M

    2012-10-15

    Making isotope ratio measurements with minimum isotope bias has always been a challenging task to mass spectrometrists, especially for the specific case of plutonium, owing to the strategic importance of the element. In order to use resonance ionization mass spectrometry (RIMS) as a tool for isotope ratio measurements, optimization of the various laser parameters and other atomic and system parameters is critical to minimize isotopic biases. Broadband simultaneous non-selective excitation of the isotopes of plutonium in the triple resonance excitation scheme with λ(1) = 420.77 nm, λ(2) = 847.28 nm, and λ(3) = 767.53 nm based on density matrix formalism has been theoretically computed for the determination of isotope ratios. The effects of the various laser parameters and other factors such as the atomization temperature and the dimensions of the atomic beam on the estimation of isotope ratios were studied. The effects of Doppler broadening, and time-dependent excitation parameters such as Rabi frequencies, ionization rate and the effect of non-Lorenztian lineshape have all been incorporated. The average laser powers and bandwidths for the three-excitation steps were evaluated for non-selective excitation. The laser intensity required to saturate the three-excitation steps were studied. The two-dimensional lineshape contour and its features were investigated, while the reversal of peak asymmetry of two-step and two-photon excitation peaks under these conditions is discussed. Optimized powers for the non-selective ionization of the three transitions were calculated as 545 mW, 150 mW and 545 mW and the laser bandwidth for all the three steps was ~20 GHz. The isotopic bias between the resonant and off-resonant isotope under the optimized conditions was no more than 9%, which is better than an earlier reported value. These optimized laser power and bandwidth conditions are better than in the earlier experimental work since these comprehensive calculations yield

  1. Spatially resolved protein hydrogen exchange measured by subzero-cooled chip-based nanoelectrospray ionization tandem mass spectrometry

    DEFF Research Database (Denmark)

    Amon, Sabine; Trelle, Morten B; Jensen, Ole N

    2012-01-01

    . After a given period of deuteration, the exchange reaction is quenched by acidification (pH 2.5) and cooling (0 °C) and the deuterated protein (or a digest thereof) is analyzed by mass spectrometry. The unavoidable loss of deuterium (back-exchange) that occurs under quench conditions is undesired...... as it leads to loss of information. Here we describe the successful application of a chip-based nanoelectrospray ionization mass spectrometry top-down fragmentation approach based on cooling to subzero temperature (-15 °C) which reduces the back-exchange at quench conditions to very low levels. For example...

  2. Measurements of total lead concentrations and of lead isotope ratios in whole blood by use of inductively coupled plasma source mass spectrometry

    International Nuclear Information System (INIS)

    Delves, H.T.; Campbell, M.J.

    1988-01-01

    Methods are described for the accurate and precise determination of total lead and its isotopic composition in whole blood using inductively coupled plasma source mass spectrometry (ICP-MS). Sensitivities of up to 3 x 10 6 counts s -1 for 208 Pb at a total lead concentration of 5 μmol l -1 (1 μg ml -1 ) enabled total blood lead levels to be measured in 4 min per sample, with a detection limit of 0.072 μmol l -1 (15 μg l -1 ). The agreement between ICP-MS and atomic absorption spectrometry (AAS) for this analysis was excellent: ICP-MS 0.996 x AAS -0.0165 μmol l -1 ; r 0.994. Isotope ratio measurements required 15 min to achieve the required accuracy and precision both of which were generally better than 0.5% for 206 Pb: 207 Pb and 208 Pb: 206 Pb isotopic lead ratios. The ICP-MS data for these ratios in ten quality control blood specimens has a mean bias relative to isotope dilution mass spectrometry of -0.412% for 206 Pb: 207 Pb ratios and of +0.055% for the 208 Pb: 206 Pb ratios. This level of accuracy and that of the total blood lead measurements is sufficient to permit application of these ICP-MS methods to environmental studies. (author)

  3. Precision measurement of radioactivity in gamma-rays spectrometry using two HPGe detectors (BEGe-6530 and GC0818-7600SL models comparison techniques: Application to the soil measurement

    Directory of Open Access Journals (Sweden)

    Guembou Shouop Cebastien Joel

    2017-01-01

    • Proved that the activity concentration determination in gamma spectrometry depended on the energy range emitted by a radionuclide. This study showed that the standard deviation measurement was less important to the result realized with BEGe-6530 HPGe model. Our findings were demonstrated that the results of the Broad Energy Germanium detector were more reliable.

  4. Applicability study of using in-situ gamma-ray spectrometry technique for 137Cs and 210Pbex inventories measurement in grassland environments

    International Nuclear Information System (INIS)

    Li Junjie; Li Yong; Wang Yanglin; Wu Jiansheng

    2010-01-01

    In-situ measurement of fallout radionuclides 137 Cs and 210 Pb ex has the potential to assess soil erosion and sedimentation rapidly. In this study, inventories of 137 Cs and 210 Pb ex in the soil of Inner Mongolia grassland were measured using an In-situ Object Counting System (ISOCS). The results from the field study indicate that in-situ gamma-ray spectrometry has the following advantages over traditional laboratory measurements: no extra time is required for sample collection, no reference inventories are required, more economic, prompt availability of the results, the ability to average radionuclide inventory over a large area, and high precision.

  5. A comparison of micropore membrane inlet mass spectrometry-derived pulmonary shunt measurement with Riley shunt in a porcine model.

    Science.gov (United States)

    Duenges, Bastian; Vogt, Andreas; Bodenstein, Marc; Wang, Hemei; Böhme, Stefan; Röhrig, Bernd; Baumgardner, James E; Markstaller, Klaus

    2009-12-01

    The multiple inert gas elimination technique was developed to measure shunt and the ratio of alveolar ventilation to simultaneous alveolar capillary blood flow in any part of the lung (V(A)'/Q') distributions. Micropore membrane inlet mass spectrometry (MMIMS), instead of gas chromatography, has been introduced for inert gas measurement and shunt determination in a rabbit lung model. However, agreement with a frequently used and accepted method for quantifying deficits in arterial oxygenation has not been established. We compared MMIMS-derived shunt (M-S) as a fraction of total cardiac output (CO) with Riley shunt (R-S) derived from the R-S formula in a porcine lung injury model. To allow a broad variance of atelectasis and therefore shunt fraction, 8 sham animals did not receive lavage, and 8 animals were treated by lung lavages with 30 mL/kg warmed lactated Ringer's solution as follows: 2 animals were lavaged once, 5 animals twice, and 1 animal 3 times. Variables were recorded at baseline and twice after induction of lung injury (T1 and T2). Retention data of sulfur hexafluoride, krypton, desflurane, enflurane, diethyl ether, and acetone were analyzed by MMIMS, and M-S was derived using a known algorithm for the multiple inert gas elimination technique. Standard formulas were used for the calculation of R-S. Forty-four pairs of M-S and R-S were recorded. M-S ranged from 0.1% to 35.4% and R-S from 3.7% to 62.1%. M-S showed a correlation with R-S described by linear regression: M-S = -4.26 + 0.59 x R-S (r(2) = 0.83). M-S was on average lower than R-S (mean = -15.0% CO, sd = 6.5% CO, and median = -15.1), with lower and upper limits of agreement of -28.0% and -2.0%, respectively. The lower and upper limits of the 95% confidence intervals were -17.0 and -13.1 (P < 0.001, Student's t-test). Shunt derived from MMIMS inert gas retention data correlated well with R-S during breathing of oxygen. Shunt as derived by MMIMS was generally less than R-S.

  6. Actinide Isotope Ratios Measured by Resonance Ionization Mass Spectrometry: Optimization of Ionization Schemes and Demonstration Using Nuclear Fallout

    Science.gov (United States)

    2017-12-01

    9 2. The Time -Dependent Schrödinger Equation ............................12 3. Stimulated Excitation to Bound States...response, including the time for reviewing instruction, searching existing data sources, gathering and maintaining the data needed, and completing and...SNM Special Nuclear Material TDC Time to Digital Converter Ti:Saph Titanium Sapphire TOF-MS Time -of-Flight Mass Spectrometry xvi THIS

  7. Determination of uranium in urine - Measurement of isotope ratios and quantification by use of inductively coupled plasma mass spectrometry

    NARCIS (Netherlands)

    Krystek, Petra; Ritsema, R.

    2002-01-01

    For analysis of uranium in urine determination of the isotope ratio and quantification were investigated by high-resolution inductively coupled plasma mass spectrometry (HR ICP-MS). The instrument used (ThermoFinniganMAT ELEMENT2) is a single-collector MS and, therefore, a stable sample-introduction

  8. On-line mass spectrometry system for measurements at single-crystal electrodes in hanging meniscus configuration

    NARCIS (Netherlands)

    Wonders, A.H.; Housmans, T.H.M.; Rosca, V.; Koper, M.T.M.

    2006-01-01

    We present the construction and some first applications of an On-line electrochemical mass spectrometry system for detecting volatile products formed during electrochemical reactions at a single-crystal electrode in hanging meniscus configuration. The system is based on a small inlet tip made of

  9. Measurement of extremely (2) H-enriched water samples by laser spectrometry: application to batch electrolytic concentration of environmental tritium samples.

    Science.gov (United States)

    Wassenaar, L I; Kumar, B; Douence, C; Belachew, D L; Aggarwal, P K

    2016-02-15

    Natural water samples artificially or experimentally enriched in deuterium ((2) H) at concentrations up to 10,000 ppm are required for various medical, environmental and hydrological tracer applications, but are difficult to measure using conventional stable isotope ratio mass spectrometry. Here we demonstrate that off-axis integrated cavity output (OA-ICOS) laser spectrometry, along with (2) H-enriched laboratory calibration standards and appropriate analysis templates, allows for low-cost, fast, and accurate determinations of water samples having δ(2) HVSMOW-SLAP values up to at least 57,000 ‰ (~9000 ppm) at a processing rate of 60 samples per day. As one practical application, extremely (2) H-enriched samples were measured by laser spectrometry and compared to the traditional (3) H Spike-Proxy method in order to determine tritium enrichment factors in the batch electrolysis of environmental waters. Highly (2) H-enriched samples were taken from different sets of electrolytically concentrated standards and low-level (tritium samples, and all cases returned accurate and precise initial low-level (3) H results. The ability to quickly and accurately measure extremely (2) H-enriched waters by laser spectrometry will facilitate the use of deuterium as a tracer in numerous environmental and other applications. For low-level tritium operations, this new analytical ability facilitated a 10-20 % increase in sample productivity through the elimination of spike standards and gravimetrics, and provides immediate feedback on electrolytic enrichment cell performance. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  10. Detection of counterfeit antiviral drug Heptodin and classification of counterfeits using isotope amount ratio measurements by multicollector inductively coupled plasma mass spectrometry (MC-ICPMS) and isotope ratio mass spectrometry (IRMS).

    Science.gov (United States)

    Santamaria-Fernandez, Rebeca; Hearn, Ruth; Wolff, Jean-Claude

    2009-06-01

    Isotope ratio mass spectrometry (IRMS) and multicollector inductively coupled plasma mass spectrometry (MC-ICP-MS) are highly important techniques that can provide forensic evidence that otherwise would not be available. MC-ICP-MS has proved to be a very powerful tool for measuring high precision and accuracy isotope amount ratios. In this work, the potential of combining isotope amount ratio measurements performed by MC-ICP-MS and IRMS for the detection of counterfeit pharmaceutical tablets has been investigated. An extensive study for the antiviral drug Heptodin has been performed for several isotopic ratios combining MC-ICP-MS and an elemental analyser EA-IRMS for stable isotope amount ratio measurements. The study has been carried out for 139 batches of the antiviral drug and analyses have been performed for C, S, N and Mg isotope ratios. Authenticity ranges have been obtained for each isotopic system and combined to generate a unique multi-isotopic pattern only present in the genuine tablets. Counterfeit tablets have then been identified as those tablets with an isotopic fingerprint outside the genuine isotopic range. The combination of those two techniques has therefore great potential for pharmaceutical counterfeit detection. A much greater power of discrimination is obtained when at least three isotopic systems are combined. The data from these studies could be presented as evidence in court and therefore methods need to be validated to support their credibility. It is also crucial to be able to produce uncertainty values associated to the isotope amount ratio measurements so that significant differences can be identified and the genuineness of a sample can be assessed.

  11. Fractionation in position-specific isotope composition during vaporization of environmental pollutants measured with isotope ratio monitoring by 13C nuclear magnetic resonance spectrometry

    International Nuclear Information System (INIS)

    Julien, Maxime; Parinet, Julien; Nun, Pierrick; Bayle, Kevin; Höhener, Patrick; Robins, Richard J.; Remaud, Gérald S.

    2015-01-01

    Isotopic fractionation of pollutants in terrestrial or aqueous environments is a well-recognized means by which to track different processes during remediation. As a complement to the common practice of measuring the change in isotope ratio for the whole molecule using isotope ratio monitoring by mass spectrometry (irm-MS), position-specific isotope analysis (PSIA) can provide further information that can be exploited to investigate source and remediation of soil and water pollutants. Position-specific fractionation originates from either degradative or partitioning processes. We show that isotope ratio monitoring by 13 C NMR (irm- 13 C NMR) spectrometry can be effectively applied to methyl tert-butylether, toluene, ethanol and trichloroethene to obtain this position-specific data for partitioning. It is found that each compound exhibits characteristic position-specific isotope fractionation patterns, and that these are modulated by the type of evaporative process occurring. Such data should help refine models of how remediation is taking place, hence back-tracking to identify pollutant sources. - Highlights: • Position-Specific Isotope Analysis (PSIA) by 13 C NMR spectrometry. • PSIA on isotope fractionation during several vaporization processes. • PSIA for isotope profiling in environment pollutants. • Intramolecular 13 C reveal normal and inverse effects, bulk values being unchanged. - PSIA in pollutants during evaporation processes shows more detailed information for discerning the nature of the process involved than does bulk isotope measurements

  12. Measurement of small ion beams by thermal ionisation mass spectrometry using new 10(13) Ohm resistors.

    Science.gov (United States)

    Koornneef, J M; Bouman, C; Schwieters, J B; Davies, G R

    2014-03-28

    We tested 5 newly manufactured - prototype - 10(13)Ohm resistors in the feedback loop of Faraday cup amplifiers to measure small ion beams by Thermal Ionisation Mass Spectrometry (TIMS). The high Ohmic resistors installed in the TRITON Plus at the VU University Amsterdam theoretically have 10 times lower noise levels relative to the default 10(11)Ohm resistors. To investigate the precision and accuracy of analyses using these new amplifiers we measured Sr and Nd isotopes of reference standards at a range of ion currents (3.2×10(-16) to 1×10(-12) A, corresponding to intensities of 32 μV to 100 mV on a default 10(11)Ohm amplifier) and on small amounts of material (100 and 10 pg). Internal precision and external reproducibility for Sr and Nd isotope ratios are both better when collected on 10(13) compared 10(12)Ohm resistors and to the default 10(11)Ohm resistors. At an (87)Sr ion current of 3×10(-14) A (3 mV on a 10(11)Ohm amplifier) the internal precision (2 SE) of (87)Sr/(86)Sr is 5 times better for 10(13)Ohm resistors compared to 10(11)Ohm resistors. The external reproducibility (2 SD) at this beam intensity is 9 times better. Multiple 100 and 10 pg Sr standards, ran to exhaustion, yielded low (87)Sr/(86)Sr compared to the long term average (e.g. 10 pg average=0.710083±164 (n=11) instead of 0.710244±12, n=73). The average off-set for 10 pg standards can be explained by a loading blank contribution of 1.3 pg. In contrast, Nd data on 100 pg and 10 pg samples are accurate suggesting that Nd loading blanks do not compromise the data. The external reproducibility of (143)Nd/(144)Nd on 100 pg samples is 125 ppm and 3.3‰ on 10 pg samples (2 RSD=relative standard deviation, n=10). Thus, variability in Nd and Sr isotope ratios in the 4th decimal place, e.g. (143)Nd/(144)Nd 0.5110-0.5119 or (87)Sr/(86)Sr 0.7100-0.7109, can be resolved in 10 to 100 pg samples provided that the procedural blanks and chemical separation are optimal. For measurements in the beam

  13. Optimization of an online heart-cutting multidimensional gas chromatography clean-up step for isotopic ratio mass spectrometry and simultaneous quadrupole mass spectrometry measurements of endogenous anabolic steroid in urine.

    Science.gov (United States)

    Casilli, Alessandro; Piper, Thomas; de Oliveira, Fábio Azamor; Padilha, Monica Costa; Pereira, Henrique Marcelo; Thevis, Mario; de Aquino Neto, Francisco Radler

    2016-11-01

    Measuring carbon isotope ratios (CIRs) of urinary analytes represents a cornerstone of doping control analysis and has been particularly optimized for the detection of the misuse of endogenous steroids. Isotope ratio mass spectrometry (IRMS) of appropriate quality, however, necessitates adequate purities of the investigated steroids, which requires extensive pre-analytical sample clean-up steps due to both the natural presence of the target analytes and the high complexity of the matrix. In order to accelerate the sample preparation and increase the automation of the process, the use of multidimensional gas chromatography (MDGC) prior to IRMS experiments, was investigated. A well-established instrumental configuration based on two independent GC ovens and one heart-cutting device was optimized. The first dimension (1D) separation was obtained by a non-polar column which assured high efficiency and good loading capacity, while the second dimension (2D), based on a mid-polar stationary phase, provided good selectivity. A flame ionization detector monitored the 1D, and the 2D was simultaneously recorded by isotope ratio and quadrupole mass spectrometry. The assembled MDGC set-up was applied for measuring testosterone, 5α- and 5β-androstanediol, androsterone, and etiocholanolone as target compounds and pregnanediol as endogenous reference compound. The urine sample were pretreated by conventional sample preparation steps comprising solid-phase extraction, hydrolysis, and liquid-liquid extraction. The extract obtained was acetylated and different aliquots were injected into the MDGC system. Two high performance liquid chromatography steps, conventionally adopted prior to CIR measurements, were replaced by the MDGC approach. The obtained values were consistent with the conventional ones. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  14. Mass measurement of cooled neutron-deficient bismuth projectile fragments with time-resolved Schottky mass spectrometry at the FRS-ESR facility

    Energy Technology Data Exchange (ETDEWEB)

    Litvinov, Yu.A.; Geissel, H. [Giessen Univ. (Germany); Radon, T. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (DE)] [and others

    2005-06-01

    Masses of 582 neutron-deficient nuclides (30{<=}Z{<=}85) were measured with time-resolved Schottky mass spectrometry at the FRS-ESR facility at GSI, 117 were used for calibration. The masses of 71 nuclides were obtained for the first time. A typical mass accuracy of 30 {mu}u was achieved. These data have entered the latest atomic mass evaluation. The mass determination of about 140 additional nuclides was possible via known energies (Q-values) of {alpha}-, {beta}-, or proton decays. The obtained results are compared with the results of other measurements. (orig.)

  15. Flame emission, atomic absorption and fluorescence spectrometry

    International Nuclear Information System (INIS)

    Horlick, G.

    1980-01-01

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

  16. ESTIMATION OF MEASUREMENT UNCERTAINTY IN THE DETERMINATION OF Fe CONTENT IN POWDERED TONIC FOOD DRINK USING GRAPHITE FURNACE ATOMIC ABSORPTION SPECTROMETRY

    Directory of Open Access Journals (Sweden)

    Harry Budiman

    2010-06-01

    Full Text Available The evaluation of uncertainty measurement in the determination of Fe content in powdered tonic food drink using graphite furnace atomic absorption spectrometry was carried out. The specification of measurand, source of uncertainty, standard uncertainty, combined uncertainty and expanded uncertainty from this measurement were evaluated and accounted. The measurement result showed that the Fe content in powdered tonic food drink sample was 569.32 µg/5g, with the expanded uncertainty measurement ± 178.20 µg/5g (coverage factor, k = 2, at confidende level 95%. The calibration curve gave the major contribution to the uncertainty of the final results.   Keywords: uncertainty, powdered tonic food drink, iron (Fe, graphite furnace AAS

  17. Measurement of the delta34S value in methionine by double spike multi-collector thermal ionization mass spectrometry using Carius tube digestion.

    Science.gov (United States)

    Mann, Jacqueline L; Kelly, W Robert

    2010-09-15

    Methionine is an essential amino acid and is the primary source of sulfur for humans. Using the double spike ((33)S-(36)S) multi-collector thermal ionization mass spectrometry (MC-TIMS) technique, three sample bottles of a methionine material obtained from the Institute for Reference Materials and Measurements have been measured for delta(34)S and sulfur concentration. The mean delta(34)S value, relative to Vienna Canyon Diablo Troilite (VCDT), determined was 10.34 +/- 0.11 per thousand (n = 9) with the uncertainty reported as expanded uncertainties (U). These delta(34)S measurements include a correction for blank which has been previously ignored in studies of sulfur isotopic composition. The sulfur concentrations for the three bottles range from 56 to 88 microg/g. The isotope composition and concentration results demonstrate the high accuracy and precision of the DS-MC-TIMS technique for measuring sulfur in methionine.

  18. Langmuir probe measurements and mass spectrometry of plasma plumes generated by laser ablation of La0.4Ca0.6MnO3

    Science.gov (United States)

    Chen, Jikun; Lunney, James G.; Lippert, Thomas; Ojeda-G-P, Alejandro; Stender, Dieter; Schneider, Christof W.; Wokaun, Alexander

    2014-08-01

    The plasma formed in vacuum by UV nanosecond laser ablation of La0.4Ca0.6MnO3 in the fluence range of 0.8 to 1.9 J cm-2 using both Langmuir probe analysis and energy-resolved mass spectrometry has been studied. Mass spectrometry shows that the main positive ion species are Ca+, Mn+, La+, and LaO+. The Ca+ and Mn+ energy distributions are quite broad and lie in the 0-100 eV region, with the average energies increasing with laser fluence. In contrast, the La+ and LaO+ distributions are strongly peaked around 10 eV. The net time-of-arrival signal derived from the measured positive ion energy distributions is broadly consistent with the positive ion signal measured by the Langmuir probe. We also detected a significant number of O- ions with energies in the range of 0 to 10 eV. The Langmuir probe was also used to measure the temporal variation of the electron density and temperature at 6 cm from the ablation target. In the period when O- ions are found at this position, the plasma conditions are consistent with those required for significant negative oxygen ion formation, as revealed by studies on radio frequency excited oxygen plasma.

  19. ICP magnetic sector multiple collector mass spectrometry and the precise measurement of isotopic compositions using nebulization of solutions and laser ablation of solids

    International Nuclear Information System (INIS)

    Halliday, A.N.; Lee, D-C.; Christensen, J.N.; Yi, W.; Hall, C.M.; Jones, C.E.; Teagle, D.A.H.; Freedman, P.A.

    1996-01-01

    Inductively-coupled plasma (ICP) sources offer considerable advantages over thermal sources because the high ionization efficiency facilitates measurements of relatively high sensitivity for elements such as Hf or Sn, which can be difficult to measure precisely with thermal ionization mass spectrometry (TIMS). The mass discrimination (bias) is larger than for TIMS, favours the heavier ions, and decreases in magnitude with increasing mass. However, in contrast to TIMS, this discrimination is largely independent of the chemical or physical properties of the element or the duration of the analysis. This has been demonstrated to high precision with a double focussing multiple collector magnetic sector mass spectrometer with an ICP source. The principle of this instrument is briefly described. The potential of the instrument for high precision isotopic measurements of a very broad range of elements, using solution aspiration or laser ablation, is indicated. 15 refs

  20. Selection of mode for the measurement of lead isotope ratios by inductively coupled plasma mass spectrometry and its application to milk powder analysis

    International Nuclear Information System (INIS)

    Dean, J.R.; Ebdon, L.; Massey, R.

    1987-01-01

    An investigation into the selection of the optimum mode for the measurement of isotope ratios in inductively coupled plasma mass spectrometry (ICP-MS) is reported, with particular reference to lead isotope ratios. Variation in the accuracy and precision achievable using the measurement modes of scanning and peak jumping are discussed. It is concluded that if sufficient sample and time are available, scanning gives best accuracy and precision. Isotope dilution analysis (IDA) has been applied to the measurement of the lead content of two dried milk powders of Australian and European origin introduced as slurries into ICP-MS. Differences in the lead isotope ratios in the two milk powders were investigated and the total lead content determined by IDA. Isotope dilution analysis permitted accurate data to be obtained with an RSD of 4.2% or milk powder containing less than 30 ng g -1 of lead. The ICP-MS technique is confirmed as a useful tool for IDA. (author)

  1. Measurement of spatial and temporal variation in volatile hazardous air pollutants in Tacoma, Washington, using a mobile membrane introduction mass spectrometry (MIMS) system.

    Science.gov (United States)

    Davey, Nicholas G; Fitzpatrick, Cole T E; Etzkorn, Jacob M; Martinsen, Morten; Crampton, Robert S; Onstad, Gretchen D; Larson, Timothy V; Yost, Michael G; Krogh, Erik T; Gilroy, Michael; Himes, Kathy H; Saganić, Erik T; Simpson, Christopher D; Gill, Christopher G

    2014-09-19

    The objective of this study was to use membrane introduction mass spectrometry (MIMS), implemented on a mobile platform, in order to provide real-time, fine-scale, temporally and spatially resolved measurements of several hazardous air pollutants. This work is important because there is now substantial evidence that fine-scale spatial and temporal variations of air pollutant concentrations are important determinants of exposure to air pollution and adverse health outcomes. The study took place in Tacoma, WA during periods of impaired air quality in the winter and summer of 2008 and 2009. Levels of fine particles were higher in winter compared to summer, and were spatially uniform across the study area. Concentrations of vapor phase pollutants measured by membrane introduction mass spectrometry (MIMS), notably benzene and toluene, had relatively uniform spatial distributions at night, but exhibited substantial spatial variation during the day-daytime levels were up to 3-fold higher at traffic-impacted locations compared to a reference site. Although no direct side-by-side comparison was made between the MIMS system and traditional fixed site monitors, the MIMS system typically reported higher concentrations of specific VOCs, particularly benzene, ethylbenzene and naphthalene, compared to annual average concentrations obtained from SUMA canisters and gas chromatographic analysis at the fixed sites.

  2. Measurement of H2O2 within Living Drosophila during Aging Using a Ratiometric Mass Spectrometry Probe Targeted to the Mitochondrial Matrix

    Science.gov (United States)

    Cochemé, Helena M.; Quin, Caroline; McQuaker, Stephen J.; Cabreiro, Filipe; Logan, Angela; Prime, Tracy A.; Abakumova, Irina; Patel, Jigna V.; Fearnley, Ian M.; James, Andrew M.; Porteous, Carolyn M.; Smith, Robin A.J.; Saeed, Saima; Carré, Jane E.; Singer, Mervyn; Gems, David; Hartley, Richard C.; Partridge, Linda; Murphy, Michael P.

    2011-01-01

    Summary Hydrogen peroxide (H2O2) is central to mitochondrial oxidative damage and redox signaling, but its roles are poorly understood due to the difficulty of measuring mitochondrial H2O2 in vivo. Here we report a ratiometric mass spectrometry probe approach to assess mitochondrial matrix H2O2 levels in vivo. The probe, MitoB, comprises a triphenylphosphonium (TPP) cation driving its accumulation within mitochondria, conjugated to an arylboronic acid that reacts with H2O2 to form a phenol, MitoP. Quantifying the MitoP/MitoB ratio by liquid chromatography-tandem mass spectrometry enabled measurement of a weighted average of mitochondrial H2O2 that predominantly reports on thoracic muscle mitochondria within living flies. There was an increase in mitochondrial H2O2 with age in flies, which was not coordinately altered by interventions that modulated life span. Our findings provide approaches to investigate mitochondrial ROS in vivo and suggest that while an increase in overall mitochondrial H2O2 correlates with aging, it may not be causative. PMID:21356523

  3. Direct coupling of electromembrane extraction to mass spectrometry – Advancing the probe functionality toward measurements of zwitterionic drug metabolites

    DEFF Research Database (Denmark)

    Kige Rye, Torstein; Fuchs, David; Pedersen-Bjergaard, Stig

    2017-01-01

    A triple-flow electromembrane extraction (EME) probe was developed and coupled directly to electrospray-ionization mass spectrometry (ESI-MS). Metabolic reaction mixtures (pH 7.4) containing drug substances and related metabolites were continuously drawn (20 μL/min) into the EME probe in one flow......-nitrophenyl octyl ether (and for some experiments containing 30% triphenyl phosphate (TPP)), and into 20 μL min-1 of formic acid as acceptor phase, which was introduced through a third flow channel. The acceptor phase was pumped directly to the MS system, and the ion intensity of extracted analytes......, the system can potentially be used for direct analysis of various kinds of chemical reactions that have to be run at pH conditions unfavorable for direct analyte extractions....

  4. Comprehensive list of metabolites measured by DI-FTICR mass spectrometry in thyme plants with contrasting tolerance to drought

    Directory of Open Access Journals (Sweden)

    Parviz Moradi

    2017-06-01

    Full Text Available This article contains data related to the main research entitled “Metabolomic approach reveals the biochemical mechanisms underlying drought stress tolerance in Thyme” (Moradi et al., 2017 [1]. Two thyme populations with contrasting drought tolerance were subjected to long term water deficit. Leaf samples harvested at the end of stress period and bi-phasic extraction carried out to get polar and non-polar fractions. Extracted samples were analyzed through Direct Infusion FT-ICR mass spectrometry. Date files comprise of four separate tables for all the putatively identified metabolites and their intensities in watered and droughted plants. P-values beside each m/z values indicate significances of difference between peak intensities of stressed and control conditions.

  5. Quantitative characterization of galectin-3-C affinity mass spectrometry measurements: Comprehensive data analysis, obstacles, shortcuts and robustness.

    Science.gov (United States)

    Haramija, Marko; Peter-Katalinić, Jasna

    2017-10-30

    Affinity mass spectrometry (AMS) is an emerging tool in the field of the study of protein•carbohydrate complexes. However, experimental obstacles and data analysis are preventing faster integration of AMS methods into the glycoscience field. Here we show how analysis of direct electrospray ionization mass spectrometry (ESI-MS) AMS data can be simplified for screening purposes, even for complex AMS spectra. A direct ESI-MS assay was tested in this study and binding data for the galectin-3C•lactose complex were analyzed using a comprehensive and simplified data analysis approach. In the comprehensive data analysis approach, noise, all protein charge states, alkali ion adducts and signal overlap were taken into account. In a simplified approach, only the intensities of the fully protonated free protein and the protein•carbohydrate complex for the main protein charge state were taken into account. In our study, for high intensity signals, noise was negligible, sodiated protein and sodiated complex signals cancelled each other out when calculating the K d value, and signal overlap influenced the Kd value only to a minor extent. Influence of these parameters on low intensity signals was much higher. However, low intensity protein charge states should be avoided in quantitative AMS analyses due to poor ion statistics. The results indicate that noise, alkali ion adducts, signal overlap, as well as low intensity protein charge states, can be neglected for preliminary experiments, as well as in screening assays. One comprehensive data analysis performed as a control should be sufficient to validate this hypothesis for other binding systems as well. Copyright © 2017 John Wiley & Sons, Ltd.

  6. Application of Isotope Dilution Mass Spectrometry for Reference Measurements of Cadmium. Copper, Mercury, Lead, Zinc and Methyl Mercury in Marine Sediment Sample

    Directory of Open Access Journals (Sweden)

    Vasileva E.

    2013-04-01

    Full Text Available Marine sediment was selected as a test sample for the laboratory inter-comparison studies organized by the Environment Laboratoryes of the International Atomic Energy. The analytical procedure to establish the reference values for the Cd, Cu, Hg, Methyl Hg, Pb and Zn amount contents was based on Isotope Dilution Inductively Coupled Plasma-Mass Spectrometry (ID ICP-MS applied as a primary method of measurement..The Hg and Methyl Hg determination will be detailed more specifically because of the problems encountered with this element, including sample homogeneity issues, memory effects and possible matrix effects during the ICP- MS measurement stage. Reference values, traceable to the SI, with total uncertainties of less than 2% relative expanded uncertainty (k=2 were obtained for Cd, Cu, Zn and Pb and around 5% for Hg and CH3Hg.

  7. High energy resolution and high count rate gamma spectrometry measurement of primary coolant of generation 4 sodium-cooled fast reactor

    International Nuclear Information System (INIS)

    Coulon, R.

    2010-01-01

    Sodium-cooled Fast Reactors are under development for the fourth generation of nuclear reactor. Breeders reactors could gives solutions for the need of energy and the preservation of uranium resources. An other purpose is the radioactive wastes production reduction by transmutation and the control of non-proliferation using a closed-cycle. These thesis shows safety and profit advantages that could be obtained by a new generation of gamma spectrometry system for SFR. Now, the high count rate abilities, allow us to study new methods of accurate power measurement and fast clad failure detection. Simulations have been done and an experimental test has been performed at the French Phenix SFR of the CEA Marcoule showing promising results for these new measurements. (author) [fr

  8. Online stable carbon isotope ratio measurement in formic acid, acetic acid, methanol and ethanol in water by high performance liquid chromatography-isotope ratio mass spectrometry

    International Nuclear Information System (INIS)

    Tagami, Keiko; Uchida, Shigeo

    2008-01-01

    A suitable analysis condition was determined for high performance liquid chromatography-isotope ratio mass spectrometry (HPLC-IRMS) while making sequential measurements of stable carbon isotope ratios of δ 13 C in formic acid, acetic acid, methanol and ethanol dissolved in water. For this online column separation method, organic reagents are not applicable due to carbon contamination; thus, water and KH 2 PO 4 at low concentrations were tested as mobile phase in combination with a HyPURITY AQUASTAR TM column. Formic acid, acetic acid, methanol and ethanol were separated when 2 mM KH 2 PO 4 aqueous solution was used. Under the determined analysis condition for HPLC-IRMS, carbon concentrations could be measured quantitatively as well as carbon isotope ratio when carbon concentration was higher than 0.4 mM L for each chemical

  9. Mass spectrometry

    DEFF Research Database (Denmark)

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

    2010-01-01

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

  10. An improved reference measurement procedure for triglycerides and total glycerides in human serum by isotope dilution gas chromatography-mass spectrometry.

    Science.gov (United States)

    Chen, Yizhao; Liu, Qinde; Yong, Sharon; Teo, Hui Ling; Lee, Tong Kooi

    2014-01-20

    Triglycerides are widely tested in clinical laboratories using enzymatic methods for lipid profiling. As enzymatic methods can be affected by interferences from biological samples, this together with the non-specific nature of triglycerides measurement makes it necessary to verify the accuracy of the test results with a reference measurement procedure. Several such measurement procedures had been published. These procedures generally involved lengthy and laborious sample preparation steps. In this paper, an improved reference measurement procedure for triglycerides and total glycerides was reported which simplifies the sample preparation steps and greatly shortens the time taken. The procedure was based on isotope dilution gas chromatography-mass spectrometry (IDGC-MS)with tripalmitin as the calibration standard. Serum samples were first spiked with isotope-labeled tripalmitin. For the measurement of triglycerides, the serum samples were subjected to lipid extraction followed by separation of triglycerides from diglycerides and monoglycerides. Triglycerides were then hydrolyzed to glycerol, derivatized and injected into the GC–MS for quantification. For the measurement of total glycerides, the serum samples were hydrolyzed directly and derivatized before injection into the GC-MS for quantification. All measurement results showed good precision with CV triglycerides and total glycerides were well within the certified ranges of the CRM, with deviation triglycerides and total glycerides.

  11. Fourier Transform Mass Spectrometry

    Science.gov (United States)

    Scigelova, Michaela; Hornshaw, Martin; Giannakopulos, Anastassios; Makarov, Alexander

    2011-01-01

    This article provides an introduction to Fourier transform-based mass spectrometry. The key performance characteristics of Fourier transform-based mass spectrometry, mass accuracy and resolution, are presented in the view of how they impact the interpretation of measurements in proteomic applications. The theory and principles of operation of two types of mass analyzer, Fourier transform ion cyclotron resonance and Orbitrap, are described. Major benefits as well as limitations of Fourier transform-based mass spectrometry technology are discussed in the context of practical sample analysis, and illustrated with examples included as figures in this text and in the accompanying slide set. Comparisons highlighting the performance differences between the two mass analyzers are made where deemed useful in assisting the user with choosing the most appropriate technology for an application. Recent developments of these high-performing mass spectrometers are mentioned to provide a future outlook. PMID:21742802

  12. Determination of uranium in urine - measurement of isotope ratios and quantification by use of inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Krystek, P.; Ritsema, R.

    2002-01-01

    For analysis of uranium in urine determination of the isotope ratio and quantification were investigated by high-resolution inductively coupled plasma mass spectrometry (HR ICP-MS). The instrument used (ThermoFinniganMAT ELEMENT2) is a single-collector MS and, therefore, a stable sample-introduction system was chosen. The methodical set-up was optimized to achieve the best precision for both the isotope ratio and the total uranium concentration in the urine matrix.Three spiked urine samples from an European interlaboratory comparison were analyzed to determine the 235 U/ 238 U isotope ratio. The ratio was found to be in the range 0.002116 to 0.007222, the latter being the natural uranium isotope ratio. The first ratio indicates the abundance of depleted uranium.The effect of storage conditions and the stability for the matrix urine were investigated by using ''real-life'' urine samples from unexposed persons in the Netherlands. For samples stored under refrigeration and acidified the results (range 0.8 to 5.3 ng L -1 U) were in the normal fluctuation range whereas a decrease in uranium concentration was observed for samples stored at room temperature without acidification. (orig.)

  13. Measurements of acetone yields from the OH-initiated oxidation of terpenes by proton-transfer-reaction mass spectrometry

    International Nuclear Information System (INIS)

    Wisthaler, A.; Lindinger, W.; Jensen, N.R.; Winterhalter, R.; Hjorth, J.

    2002-01-01

    Biogenic VOCs (Volatile Organic Compounds) are known to be emitted in large quantities from vegetation exceeding largely global emissions of anthropogenic VOCs. Monoterpenes (C 10 H 16 ) are important constituents of biogenic VOC emissions. The atmospheric oxidation of Monoterpenes appears to be a potentially relevant source of acetone in the atmosphere. Acetone is present as a significant trace gas in the whole troposphere and influences in particular the atmospheric chemistry in the upper troposphere by substantially contributing to the formation of HO x radicals and peroxyacetyl nitrate (PAN). Acetone is formed promptly, following attack by the OH-radical on the terpene, via a series of highly unstable radical intermediates, but it is also formed slowly via the degradation of stable non-radical intermediates such as pinonaldehyde and nopinone. In order to investigate the relative importance of these processes, the OH-initiated oxidation of α-pinene and β-pinene was investigated in a chamber study, where the concentrations of monoterpenes, acetone, pinonaldehyde and nopinone were monitored by proton-transfer-reaction mass spectrometry (PTR-MS). It was found that significant amounts of acetone are formed directly, whenα-pinene and β-pinene are oxidized by the OH radical, but also secondary chemistry (degradation of primary reaction products) gives a significant contribution to the formation of acetone from monoterpenes. It can be concluded that atmospheric oxidation of monoterpenes contributes a significant fraction to the global acetone source strength. (nevyjel)

  14. Measurement of rimantadine in plasma by capillary gas chromatography/mass spectrometry with a deuterium-labeled internal standard

    International Nuclear Information System (INIS)

    Herold, D.A.; Anonick, P.K.; Kinter, M.; Hayden, F.G.

    1988-01-01

    Rimantadine is a synthetic antiviral agent used in prophylaxis and in treating the early stages of uncomplicated influenza A illness. We describe a stable isotope-dilution assay involving capillary gas chromatography/mass spectrometry. We used 200 ng of d3-rimantadine, added to 1 mL of plasma, as the internal standard. The rimantadine was extracted from the plasma with a Bond-Elut CN column, the column was washed with water, and the rimantadine was eluted with methanol, dried, and treated to form the t-butyldimethylsilyl derivative. The mass spectrometer was operated in the selected ion monitoring mode. Ions at m/z 236 and m/z 239 were monitored, corresponding to the loss of C4H9 from the rimantadine derivative and d3-rimantadine, respectively. Within-run precision (CVs) ranged from 8.9% at 29 micrograms/L to 3.2% at 1666 micrograms/L. Corresponding data for between-run precision were 5.4% and 1.7%. Treated volunteers (n = 86) provided plasma samples with a concentration range of 153 to 1127 micrograms/L. This simplified method allows rapid, precise assay of rimantadine in plasma

  15. Determination of microcystin-LR in drinking water using UPLC tandem mass spectrometry-matrix effects and measurement.

    Science.gov (United States)

    Li, Wei; Duan, Jinming; Niu, Chaoying; Qiang, Naichen; Mulcahy, Dennis

    2011-10-01

    A simple detection method using ultra-performance liquid chromatography electrospray ionisation tandem mass spectrometry (UPLC-ESI-MS-MS) coupled with the sample dilution method for determining trace microcystin-LR (MC-LR) in drinking water is presented. The limit of detection (LOD) was 0.04 µg/L and the limit of quantitation (LOQ) was 0.1 µg/L. Water matrix effects of ionic strength, dissolved organic carbon (DOC) and pH were examined. The results indicate that signal detection intensity for MC-LR was significantly suppressed as the ionic strength increased from ultrapure water condition, whereas it increased slightly with solution pH and DOC at low concentrations. However, addition of methanol (MeOH) into the sample was able to counter the signal suppression effects. In this study, dilution of the tap water sample by adding 4% MeOH (v/v) was observed to be adequate to compensate for the signal suppression. The recoveries of the samples fortified with MC-LR (0.2, 1, and 10 µg/L) for three different tap water samples ranged from 84.4% to 112.9%.

  16. Conditions to obtain precise and true measurements of the intramolecular {sup 13}C distribution in organic molecules by isotopic {sup 13}C nuclear magnetic resonance spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Bayle, Kevin [EBSI Team, Interdisciplinary Chemistry: Synthesis, Analysis, Modelling (CEISAM), University of Nantes-CNRS UMR 6230, 2 Rue de la Houssinière, BP 92208, F-44322, Nantes Cedex 3 (France); Gilbert, Alexis [Department of Environmental Chemistry and Engineering, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8503 (Japan); Earth–Life Science Institute, Tokyo Institute of Technology, Meguro, Tokyo 152-8551 (Japan); Julien, Maxime [EBSI Team, Interdisciplinary Chemistry: Synthesis, Analysis, Modelling (CEISAM), University of Nantes-CNRS UMR 6230, 2 Rue de la Houssinière, BP 92208, F-44322, Nantes Cedex 3 (France); Yamada, Keita [Department of Environmental Chemistry and Engineering, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8503 (Japan); Silvestre, Virginie; Robins, Richard J.; Akoka, Serge [EBSI Team, Interdisciplinary Chemistry: Synthesis, Analysis, Modelling (CEISAM), University of Nantes-CNRS UMR 6230, 2 Rue de la Houssinière, BP 92208, F-44322, Nantes Cedex 3 (France); Yoshida, Naohiro [Department of Environmental Chemistry and Engineering, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8503 (Japan); Earth–Life Science Institute, Tokyo Institute of Technology, Meguro, Tokyo 152-8551 (Japan); Remaud, Gérald S., E-mail: gerald.remaud@univ-nantes.fr [EBSI Team, Interdisciplinary Chemistry: Synthesis, Analysis, Modelling (CEISAM), University of Nantes-CNRS UMR 6230, 2 Rue de la Houssinière, BP 92208, F-44322, Nantes Cedex 3 (France)

    2014-10-10

    Highlights: • Evaluation of the trueness and precision criteria of isotopic {sup 13}C NMR spectrometry. • Use of bi-labelled [1,2-{sup 13}C{sub 2}]acetic acid to determine the performance of the instrumental response. • Inter-calibration of the {sup 13}C intramolecular composition of acetic acid using the technique GC-Py–irm-MS. - Abstract: Intramolecular {sup 13}C composition gives access to new information on the (bio) synthetic history of a given molecule. Isotopic {sup 13}C NMR spectrometry provides a general tool for measuring the position-specific {sup 13}C content. As an emerging technique, some aspects of its performance are not yet fully delineated. This paper reports on (i) the conditions required to obtain satisfactory trueness and precision for the determination of the internal {sup 13}C distribution, and (ii) an approach to determining the “absolute” position-specific {sup 13}C content. In relation to (i), a precision of <1% can be obtained whatever the molecule on any spectrometer, once quantitative conditions are met, in particular appropriate proton decoupling efficiency. This performance is a prerequisite to the measurement of isotope fractionation either on the transformed or residual compound when a chemical reaction or process is being studied. The study of the trueness has revealed that the response of the spectrometer depends on the {sup 13}C frequency range of the studied molecule, i.e. the chemical shift range. The “absolute value” and, therefore, the trueness of the {sup 13}C NMR measurements has been assessed on acetic acid and by comparison to the results obtained on the fragments from COOH and CH{sub 3} by isotopic mass spectrometry coupled to a pyrolysis device (GC-Py–irm-MS), this technique being the reference method for acetic acid. Of the two NMR spectrometers used in this work, one gave values that corresponded to those obtained by GC-Py–irm-MS (thus, the “true” value) while the other showed a bias, which was

  17. Rapid measurement of 13C-enrichment of acetic, propionic and butyric acids in plasma with solid phase microextraction coupled to gas chromatography-mass spectrometry

    International Nuclear Information System (INIS)

    Moreau, N.M.; Delepee, R.; Maume, D.; Le Bizec, B.; Nguyen, P.G.; Champ, M.M.; Martin, L.J.; Dumon, H.J.

    2004-01-01

    An analytical procedure based on solid phase microextraction (SPME) has been developed to quantify [1- 13 C]-labelled short-chain fatty acids (SCFAs)--mainly acetic, propionic and butyric acids--in a small volume (120 μl) of deproteinised plasma (corresponding to 200 μl of raw plasma) by gas chromatography-mass spectrometry (GC-MS) analysis. Simultaneous SCFA extraction was optimal after 5 min using a 75 μm Carboxen/polydimethylsiloxane-coated fiber. The base peak of the three analytes has been characterised by middle-resolution mass spectrometry (R>6000). All these data allowed the specificity reinforcement of the measure. The validation of the method also considered the linearity and the repeatability of the [ 13 C]SCFA measurements by SPME-GC-MS. Results were linear in a range from 5 to 100 mol% of [ 13 C]SCFA enrichment and the method provided a good intra-day (R.S.D. 13 C]butyric acid) by cecal infusion before blood sampling in portal vein. Results of [1- 13 C]butyric acid enrichment showed an excellent correlation (r 2 =0.9832; n=30) with data obtained on the same samples using a previously published procedure based on diethyl extraction and derivatisation before GC-MS analyses. SPME coupled to GC-MS appears to be a powerful analytical tool for the direct isotopic measurements of low deproteinised plasma volume avoiding consequently preliminary treatment such as extraction or derivatisation. The presented method could be of great interest for real time [ 13 C]SCFA plasma determination of in metabolic in vivo studies in small animal models

  18. A comparison using Faraday cups with 1013 Ω amplifiers and a secondary electron multiplier to measure Os isotopes by negative thermal ionization mass spectrometry.

    Science.gov (United States)

    Wang, Guiqin; Sun, Tiantian; Xu, Jifeng

    2017-10-15

    According to the Johnson-Nyquist noise equation, the value of electron noise is proportional to the square root of the resistor value. This relationship gives a theoretical improvement of 100 in the signal/noise ratio by going from 10 11 Ω to 10 13 Ω amplifiers for Faraday detection in thermal ionization mass spectrometry (TIMS). We measured Os isotopes using static Faraday cups with 10 13 Ω amplifiers in negative thermal ionization mass spectrometry (NTIMS) and compared the results with those obtained with 10 11 Ω amplifiers and by peak-hopping on a single secondary electron multiplier (SEM). We analysed large loads of Os (1 μg) at a range of intensities of 187 OsO 3 (0.02-10 mV) in addition to small loads of Os (5-500 pg) to compare the results of the three methods. Using 10 13 Ω amplifiers, the long-term reproducibility determined from Merck Os was 187 Os/ 188 Os = 0.1211 ± 0.0086 and 0.120229 ± 0.000034 at 0.02 mV and 10 mV of 187 OsO 3 intensities. Meanwhile, the analysed JMC Os loadings of 5 and 500 pg showed 187 Os/ 188 Os = 0.10669 ± 0.00036 and 0.106807 ± 0.000023. In comparison, the values measured by the SEM were 187 Os/ 188 Os = 0.10704 ± 0.00056 and 0.10690 ± 0.00013. All errors are in 2 standard deviation (SD). Both the accuracy and the precision determined using the 10 13 Ω amplifiers and the SEM are identical when the Os amounts are within 10-50 pg. However, the former analysis time can be shortened by approximately two-thirds. The SEM measurement is still the most precise method for Os amounts 50 pg. Copyright © 2017 John Wiley & Sons, Ltd.

  19. Measurement of electro-sprayed 238 and 239+240 plutonium isotopes using 4{pi}-alpha spectrometry. Application to environmental samples; Spectrometrie alpha 4{pi} de sources d'actinides realisees par electronebulisation. Developpement et optimisation d'un protocole applique au mesurage des isotopes 238 et 239+240 du plutonium dans l'environnement

    Energy Technology Data Exchange (ETDEWEB)

    Charmoille-Roblot, M. [CEA/Fontenay-aux-Roses, Dept. de Protection de l' Environnement (DPRE), 92 (France)]|[Paris-11 Univ., 91 - Orsay (France)

    1999-07-01

    A new protocol for plutonium deposition using the electro-spray technique coupled with 4{pi}-{alpha} spectrometry is proposed to improve the detection limit, shorten the counting time. In order to increase the detection efficiency, it was proposed to measure 238 and 239+240 plutonium isotopes electro-sprayed deposit simultaneously on both sides of the source support, that must be as transparent as possible to alpha-emissions, in a two-alpha detectors chamber. A radiochemical protocol was adapted to electro-spray constraints and a very thin carbon foil was selected for 4{pi} -alpha spectrometry. The method was applied to a batch of sediment samples and gave the same results as an electrodeposited source measured using conventional alpha spectrometry with a 25 % gain on counting time and 10 % on plutonium 238 detection limit. Validation and application of the technique have been made on reference samples. (author)

  20. The calibration of the intramolecular nitrogen isotope distribution in nitrous oxide measured by isotope ratio mass spectrometry.

    Science.gov (United States)

    Westley, Marian B; Popp, Brian N; Rust, Terri M

    2007-01-01

    Two alternative approaches for the calibration of the intramolecular nitrogen isotope distribution in nitrous oxide using isotope ratio mass spectrometry have yielded a difference in the 15N site preference (defined as the difference between the delta15N of the central and end position nitrogen in NNO) of tropospheric N2O of almost 30 per thousand. One approach is based on adding small amounts of labeled 15N2O to the N2O reference gas and tracking the subsequent changes in m/z 30, 31, 44, 45 and 46, and this yields a 15N site preference of 46.3 +/- 1.4 per thousand for tropospheric N2O. The other involves the synthesis of N2O by thermal decomposition of isotopically characterized ammonium nitrate and yields a 15N site preference of 18.7 +/- 2.2 per thousand for tropospheric N2O. Both approaches neglect to fully account for isotope effects associated with the formation of NO+ fragment ions from the different isotopic species of N2O in the ion source of a mass spectrometer. These effects vary with conditions in the ion source and make it impossible to reproduce a calibration based on the addition of isotopically enriched N2O on mass spectrometers with different ion source configurations. These effects have a much smaller impact on the comparison of a laboratory reference gas with N2O synthesized from isotopically characterized ammonium nitrate. This second approach was successfully replicated and leads us to advocate the acceptance of the site preference value 18.7 +/- 2.2 per thousand for tropospheric N2O as the provisional community standard until further independent calibrations are developed and validated. We present a technique for evaluating the isotope effects associated with fragment ion formation and revised equations for converting ion signal ratios into isotopomer ratios. Copyright 2007 John Wiley & Sons, Ltd.

  1. Atmospheric measurements of gas-phase HNO3 and SO2 using chemical ionization mass spectrometry during the MINATROC field campaign 2000 on Monte Cimone

    Directory of Open Access Journals (Sweden)

    M. Hanke

    2003-01-01

    Full Text Available The EU-project MINATROC (MINeral dust And TROpospheric Chemistry aims at enabling an estimation of the influence of mineral dust, a major, but to date largely ignored component of tropospheric aerosol, on tropospheric oxidant cycles. Within the scope of this project continuous atmospheric measurements of gas-phase HNO3 and SO2 were conducted in June and July 2000 at the CNR WMO station, situated on Monte Cimone (MTC (44°11' N --10°42' E, 2165 m asl, Italy. African air transporting dust is occasionally advected over the Mediterranean Sea to the site, thus mineral aerosol emitted from Africa will encounter polluted air masses and provide ideal conditions to study their interactions. HNO3 and SO2 were measured with an improved CIMS (chemical ionization mass spectrometry system for ground-based measurements that was developed and built at MPI-K Heidelberg. Since HNO3  is a very sticky compound special care was paid for the air-sampling and background-measurement system. Complete data sets could be obtained before, during and after major dust intrusions. For the first time these measurements might provide a strong observational indication of efficient uptake of gas-phase HNO3 by atmospheric mineral-dust aerosol particles.

  2. Interlaboratory Trial for Measurement of Vitamin D and 25-Hydroxyvitamin D [25(OH)D] in Foods and a Dietary Supplement Using Liquid Chromatography-Mass Spectrometry

    DEFF Research Database (Denmark)

    Roseland, Janet Maxwell; Patterson, Kristine Y; Andrews, Karen W

    2016-01-01

    performance has been needed. The primary goal of this study was to evaluate whether vitamin D3 and 25(OH)D3 concentrations in food and DS materials could be measured with acceptable reproducibility. Five experienced laboratories from the United States and other countries participated, all using liquid......Assessment of total vitamin D intake from foods and dietary supplements (DSs) may be incomplete if 25-hydroxyvitamin D [25(OH)D] intake is not included. However, 25(OH)D data for such intake assessments are lacking, no food or DS reference materials (RMs) are available, and comparison of laboratory...... chromatography tandem-mass spectrometry but no common analytical protocol; however, various methods were used for determining vitamin D3 in the DS. Five animal-based materials (including three commercially available RMs) and one DS were analyzed. Reproducibility results for the materials were acceptable. Thus...

  3. UPLC-MRM Mass Spectrometry Method for Measurement of the Coagulation Inhibitors Dabigatran and Rivaroxaban in Human Plasma and Its Comparison with Functional Assays.

    Science.gov (United States)

    Kuhn, Joachim; Gripp, Tatjana; Flieder, Tobias; Dittrich, Marcus; Hendig, Doris; Busse, Jessica; Knabbe, Cornelius; Birschmann, Ingvild

    2015-01-01

    The fast, precise, and accurate measurement of the new generation of oral anticoagulants such as dabigatran and rivaroxaban in patients' plasma my provide important information in different clinical circumstances such as in the case of suspicion of overdose, when patients switch from existing oral anticoagulant, in patients with hepatic or renal impairment, by concomitant use of interaction drugs, or to assess anticoagulant concentration in patients' blood before major surgery. Here, we describe a quick and precise method to measure the coagulation inhibitors dabigatran and rivaroxaban using ultra-performance liquid chromatography electrospray ionization-tandem mass spectrometry in multiple reactions monitoring (MRM) mode (UPLC-MRM MS). Internal standards (ISs) were added to the sample and after protein precipitation; the sample was separated on a reverse phase column. After ionization of the analytes the ions were detected using electrospray ionization-tandem mass spectrometry. Run time was 2.5 minutes per injection. Ion suppression was characterized by means of post-column infusion. The calibration curves of dabigatran and rivaroxaban were linear over the working range between 0.8 and 800 μg/L (r >0.99). Limits of detection (LOD) in the plasma matrix were 0.21 μg/L for dabigatran and 0.34 μg/L for rivaroxaban, and lower limits of quantification (LLOQ) in the plasma matrix were 0.46 μg/L for dabigatran and 0.54 μg/L for rivaroxaban. The intraassay coefficients of variation (CVs) for dabigatran and rivaroxaban were method comparison between our UPLC-MRM MS method, the commercially available automated Direct Thrombin Inhibitor assay (DTI assay) for dabigatran measurement from CoaChrom Diagnostica, as well as the automated anti-Xa assay for rivaroxaban measurement from Chromogenix both performed by ACL-TOP showed a high degree of correlation. However, UPLC-MRM MS measurement of dabigatran and rivaroxaban has a much better selectivity than classical functional

  4. Age trends in estradiol and estrone levels measured using liquid chromatography tandem mass spectrometry in community-dwelling men of the Framingham Heart Study.

    Science.gov (United States)

    Jasuja, Guneet Kaur; Travison, Thomas G; Davda, Maithili; Murabito, Joanne M; Basaria, Shehzad; Zhang, Anqi; Kushnir, Mark M; Rockwood, Alan L; Meikle, Wayne; Pencina, Michael J; Coviello, Andrea; Rose, Adam J; D'Agostino, Ralph; Vasan, Ramachandran S; Bhasin, Shalender

    2013-06-01

    Age trends in estradiol and estrone levels in men and how lifestyle factors, comorbid conditions, testosterone, and sex hormone-binding globulin affect these age trends remain poorly understood, and were examined in men of the Framingham Heart Study. Estrone and estradiol concentrations were measured in morning fasting samples using liquid chromatography tandem mass spectrometry in men of Framingham Offspring Generation. Free estradiol was calculated using a law of mass action equation. There were 1,461 eligible men (mean age [±SD] 61.1±9.5 years and body mass index [BMI] 28.8±4.5kg/m(2)). Total estradiol and estrone were positively associated with age, but free estradiol was negatively associated with age. Age-related increase in total estrone was greater than that in total estradiol. Estrone was positively associated with smoking, BMI, and testosterone, and total and free estradiol with diabetes, BMI, testosterone, and comorbid conditions; additionally, free estradiol was associated negatively with smoking. Collectively, age, BMI, testosterone, and other health and behavioral factors explained only 18% of variance in estradiol, and 9% of variance in estrone levels. Men in the highest quintile of estrone levels had significantly higher age and BMI, and a higher prevalence of smoking, diabetes, and cardiovascular disease than others, whereas those in the highest quintile of estradiol had higher BMI than others. Total estrone and estradiol levels in men, measured using liquid chromatography tandem mass spectrometry, revealed significant age-related increases that were only partially accounted for by cross-sectional differences in BMI, diabetes status, and other comorbidities and health behaviors. Longitudinal studies are needed to confirm these findings.

  5. Quantitative nuclear magnetic resonance spectrometry II. Purity of phosphorus-based agrochemicals glyphosate (N-(phosphonomethyl)-glycine) and profenofos (O-(4-bromo-2-chlorophenyl) O-ethyl S-propyl phosphorothioate) measured by 1H and 31P QNMR spectrometry

    International Nuclear Information System (INIS)

    Saed Al Deen, Tareq; Brynn Hibbert, D.; Hook, James M.; Wells, Robert J.

    2002-01-01

    The purities of the widely-used herbicide glyphosate (N-(phosphonomethyl)glycine), and the insecticide profenofos (O-(4-bromo-2-chlorophenyl) O-ethyl S-propyl phosphorothioate) were determined by 1 H and 31 P quantitative nuclear magnetic resonance (QNMR) spectrometry using an internal standard. QNMR does not need a standard reference of the same target analyte, in contrast to chromatographic methods, but only a compound containing the nucleus of interest. Sodium acetate and sodium phosphate of known purity were chosen as internal standards for 1 H NMR and 31 P NMR), respectively for the water soluble glyphosate and a single internal standard, trimethyl phosphate for both 1 H and 31 P NMR quantitative analysis of the organic soluble profenofos. These standards have NMR peaks that do not interfere with those of the analyte, they are chemically inert and are soluble in the deuterated solvent. The average purity of glyphosate obtained by 1 H NMR (97.07%, σ=0.68) agreed with that by 31 P NMR (96.53%, σ=0.90; ANOVA, P=0.074) for the five batches provided by the manufacturer according to the procedures for chemical registration in Australia. The standard deviations of seven independent analyses of a single batch by 1 H NMR and 31 P NMR were σ=0.24% and σ=0.33%, respectively, values which confirm the exceptional precision of the method. The purity of profenofos by 1 H NMR (94.63%, σ=0.14) also agreed with that by 31 P NMR (94.62%, σ=0.59; ANOVA, P=0.97). Uncertainty budgets for the measured purities of glyphosate and profenofos show that the uncertainty in the purity of the internal standard is a major contributor to the uncertainty of the result. NMR was also used to establish the impurity profile of both compounds, and quantify the impurities present

  6. Direct coupling of electromembrane extraction to mass spectrometry - Advancing the probe functionality toward measurements of zwitterionic drug metabolites.

    Science.gov (United States)

    Rye, Torstein Kige; Fuchs, David; Pedersen-Bjergaard, Stig; Petersen, Nickolaj Jacob

    2017-08-29

    A triple-flow electromembrane extraction (EME) probe was developed and coupled directly to electrospray-ionization mass spectrometry (ESI-MS). Metabolic reaction mixtures (pH 7.4) containing drug substances and related metabolites were continuously drawn (20 μL/min) into the EME probe in one flow channel, and mixed inside the probe with 7.5 μL min -1 of 1 M formic acid as make-up flow from a second flow channel. Following this acidification, the drug substances and their related metabolites were continuously extracted by EME at 400 V, across a supported liquid membrane (SLM) comprising 2-nitrophenyl octyl ether (and for some experiments containing 30% triphenyl phosphate (TPP)), and into 20 μL min -1 of formic acid as acceptor phase, which was introduced through a third flow channel. The acceptor phase was pumped directly to the MS system, and the ion intensity of extracted analytes was followed continuously as function of time. The triple-flow EME probe was used for co-extraction of positively charged parent drugs and their zwitterionic drug metabolites (hydroxyzine and its carboxylic acid metabolite cetirizine; and vortioxetine and its carboxylic acid metabolite Lu AA34443). While the zwitterionic metabolites could not be extracted at pH 7.4, it was shown that by acidifying the sample solution the zwitterionic metabolites could be extracted effectively. Various extraction parameters like make-up flow, extraction voltage and SLM composition were optimized for simultaneous extraction of parent drugs and metabolites. It was found that TPP added to the SLM improved extraction efficiencies of certain drug metabolites. Finally the optimized and characterized triple-flow EME probe was used for online studying the in-vitro metabolism of hydroxyzine and vortioxetine by rat liver microsomes. Due to the automated pre-extraction acidification of the rat liver microsomal solutions, it was possible to continuously monitor formation of the zwitterionic drug

  7. 226Ra measurement by thermal ionisation mass spectrometry: Use of 226Ra and 14C for groundwater dating

    International Nuclear Information System (INIS)

    Dever, L.

    1997-01-01

    Recent developments in thermal ionisation mass spectrometry (TIMS) and in chemical separation Ra and Ba allow to analyse 226 Ra on smaller water samples ( 3 litres). The sampling has been realised on the Chalk aquifer of the Paris basin. The water samples have been collected in the unsaturated zone using in situ filtering devices and in the unconfined and confined parts of the aquifer in the boreholes used for public water supply. 226 Ra contents vary from 0.064±0.02 dpm/kg (n=6) in the unsaturated zone to 0.119±0.069 dpm/kg (n=7) in the unconfined aquifer and 0.319±0.057 dpm/kg (n=9) in the confined aquifer. For all the samples the 226 Ra/ 238 U activity ratios are much lower than the secular equilibrium. This points out that the two isotopes have different input function in the water during the mineralisation of the solution. The good correlation (r 2 =0.9) between the 226 Ra and Sr indicates that dissolution of Chalk is the dominant mechanism of mineralisation in 226 Ra of the solution. In the Chalk the mineralisation of the water occurs in the first metres of the unsaturated zone, during the water percolation the water rock interaction takes place through dissolution and precipitation of calcite in a non steady state. According to his distribution coefficient Sr is then a better tracer of dissolution/precipitation process than Ba. Using a geochemical model based on 226 Ra/Sr and Sr/Ca ratios an 'age' of the water could be determined. With 226 Ra half life of 1620 years we obtain 'ages' varying from 150 years to 1950 years in the unconfined aquifer. For the confined part of the aquifer where the redox condition is different it is necessary to use a geochemical model based on the U concentration in the water, the 226 Ra gives in such case ages varying from 1.8ka to 12.8ka. The radiocarbon ages obtained through usual chemical and/or isotopic models are quite similar and an isochrome between 226 Ra and 14 C ages can be calculated between 0 and 8ka

  8. Measurement of Endogenous versus Exogenous Formaldehyde-Induced DNA-Protein Crosslinks in Animal Tissues by Stable Isotope Labeling and Ultrasensitive Mass Spectrometry.

    Science.gov (United States)

    Lai, Yongquan; Yu, Rui; Hartwell, Hadley J; Moeller, Benjamin C; Bodnar, Wanda M; Swenberg, James A

    2016-05-01

    DNA-protein crosslinks (DPC) arise from a wide range of endogenous and exogenous chemicals, such as chemotherapeutic drugs and formaldehyde. Importantly, recent identification of aldehydes as endogenous genotoxins in Fanconi anemia has provided new insight into disease causation. Because of their bulky nature, DPCs pose severe threats to genome stability, but previous methods to measure formaldehyde-induced DPCs were incapable of discriminating between endogenous and exogenous sources of chemical. In this study, we developed methods that provide accurate and distinct measurements of both exogenous and endogenous DPCs in a structurally specific manner. We exposed experimental animals to stable isotope-labeled formaldehyde ([(13)CD2]-formaldehyde) by inhalation and performed ultrasensitive mass spectrometry to measure endogenous (unlabeled) and exogenous ((13)CD2-labeled) DPCs. We found that exogenous DPCs readily accumulated in nasal respiratory tissues but were absent in tissues distant to the site of contact. This observation, together with the finding that endogenous formaldehyde-induced DPCs were present in all tissues examined, suggests that endogenous DPCs may be responsible for increased risks of bone marrow toxicity and leukemia. Furthermore, the slow rate of DPC repair provided evidence for the persistence of DPCs. In conclusion, our method for measuring endogenous and exogenous DPCs presents a new perspective for the potential health risks inflicted by endogenous formaldehyde and may inform improved disease prevention and treatment strategies. Cancer Res; 76(9); 2652-61. ©2016 AACR. ©2016 American Association for Cancer Research.

  9. Measurement of radon concentration in water by means of {alpha}, {gamma} spectrometry. Radon concentration in ground and spring water in Hiroshima Prefecture

    Energy Technology Data Exchange (ETDEWEB)

    Shizuma, Kiyoshi [Hiroshima Univ. (Japan)

    1997-02-01

    Radon ({sup 222}Rn, T{sub 1/2}=3.8235{+-}0.0003d) is {alpha}-ray releasing nuclide, so that it can not be detected by {gamma}-ray measurement. But, the daughter nuclides {sup 214}Pb (T{sub 1/2}=26.8 min) and {sup 214}Bi (T{sub 1/2}=19.9 min) release {gamma}-ray, accordingly they are measured by Ge detector. Their radioactive equilibrium is kept in the closed vessel, because their half-lives are shorter than that of radon. We developed a measurement method of radon concentration by means of {gamma}-spectrometry. We applied this method to catch radon in the atmosphere by active carbon. The same principle can be applied to radon in water. Radon concentrations in the ground water were measured in 22 points in the Higashi-Hiroshima city and 82 points in the Hiroshima prefecture. The efficiencies of {gamma}-ray were determined. The radon concentration showed between 11 and 459 Bq/l and the average was 123 Bq/l. The high concentration of radon was distributed in the spring of granitic layer and higher concentration of radon were observed in the ground water of fault. (S.Y.)

  10. Instruments for radiation measurement in life sciences (4). VI. Use of Accelerator mass spectrometry in studies on drug metabolism and pharmacokinetics

    International Nuclear Information System (INIS)

    Ikeda, Toshihiko

    2005-01-01

    Non-clinical and clinical uses of accelerator mass spectrometry (AMS) are described mainly on studies of drug metabolism and pharmacokinetics from a view of new drug development. AMS is applicable as a highly sensitive method to measure plasma drug concentrations. Measurement of 14 C-labeled compounds less than 1 dpm/sample or of parathyroid hormone-related protein (PTHrP), in combination of AMS and radioimmunoassay without radioactive waste release is described as an example. Cases of measuring DNA-adduct are also described involving human studies using 14 C-mutagen (a quinoxaline derivative derived from burned amino acid, given in a microdose of 304 ng/kg, 4.3 μCi/body). Plasma concentration measurement, mass balance study and metabolite identification of 14 C-GI1817771 (a drug candidate) are a typical AMS application for a pharmacokinetic study in human in a microdose (121 Bq/body). Metabolites of 14 C-compound A in rat platelet are identified by the author. As above, AMS makes it possible to conduct the pharmacokinetic study in human at a microdose with no significant radiation exposure, which will promote the efficient new drug development. (N.I.)

  11. The determination of carbon dioxide concentration using atmospheric pressure ionization mass spectrometry/isotopic dilution and errors in concentration measurements caused by dryers.

    Science.gov (United States)

    DeLacy, Brendan G; Bandy, Alan R

    2008-01-01

    An atmospheric pressure ionization mass spectrometry/isotopically labeled standard (APIMS/ILS) method has been developed for the determination of carbon dioxide (CO(2)) concentration. Descriptions of the instrumental components, the ionization chemistry, and the statistics associated with the analytical method are provided. This method represents an alternative to the nondispersive infrared (NDIR) technique, which is currently used in the atmospheric community to determine atmospheric CO(2) concentrations. The APIMS/ILS and NDIR methods exhibit a decreased sensitivity for CO(2) in the presence of water vapor. Therefore, dryers such as a nafion dryer are used to remove water before detection. The APIMS/ILS method measures mixing ratios and demonstrates linearity and range in the presence or absence of a dryer. The NDIR technique, on the other hand, measures molar concentrations. The second half of this paper describes errors in molar concentration measurements that are caused by drying. An equation describing the errors was derived from the ideal gas law, the conservation of mass, and Dalton's Law. The purpose of this derivation was to quantify errors in the NDIR technique that are caused by drying. Laboratory experiments were conducted to verify the errors created solely by the dryer in CO(2) concentration measurements post-dryer. The laboratory experiments verified the theoretically predicted errors in the derived equations. There are numerous references in the literature that describe the use of a dryer in conjunction with the NDIR technique. However, these references do not address the errors that are caused by drying.

  12. Activation Measurements for Thermal Neutrons, U.S. Measurements of 36Cl in Mineral Samples from Hiroshima and Nagasaki; and Measurement of 63 Ni in Copper Samples From Hiroshima by Accelerator Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Tore Straume; Alfredo A. Marchetti; Stephen D. Egbert; James A. Roberts; Ping Men; Shoichiro Fujita; Kiyoshi Shizuma; Masaharu Hoshi; G. Rugel; W. Ruhm; G. Korschinek; J. E. McAninch; K. L. Carroll; T. Faestermann; K. Knie; R. E. Martinelli; A. Wallner; C. Wallner

    2005-01-14

    The present paper presents the {sup 36}Cl measurement effort in the US. A large number of {sup 36}Cl measurements have been made in both granite and concrete samples obtained from various locations and distances in Hiroshima and Nagasaki. These measurements employed accelerator mass spectrometry (AMS) to quantify the number of atoms of {sup 36}Cl per atom of total Cl in the sample. Results from these measurements are presented here and discussed in the context of the DS02 dosimetry reevaluation effort for Hiroshima and Nagasaki atomic-bomb survivors. The production of {sup 36}Cl by bomb neutrons in mineral samples from Hiroshima and Nagasaki was primarily via the reaction {sup 35}Cl(n,{gamma}){sup 36}Cl. This reaction has a substantial thermal neutron cross-section (43.6 b at 0.025 eV) and the product has a long half-life (301,000 y). hence, it is well suited for neutron-activation detection in Hiroshima and Nagasaki using AMS more than 50 years after the bombings. A less important reaction for bomb neutrons, {sup 39}K(n,{alpha}){sup 36}Cl, typically produces less than 10% of the {sup 36}Cl in mineral samples such as granite and concrete, which contain {approx} 2% potassium. In 1988, only a year after the publication of the DS86 final report (Roesch 1987), it was demonstrated experimentally that {sup 36}Cl measured using AMS should be able to detect the thermal neutron fluences at the large distances most relevant to the A-bomb survivor dosimetry. Subsequent measurements in mineral samples from both Hiroshima and Nagasaki validated the experimental findings. The potential utility of {sup 36}Cl as a thermal neutron detector in Hiroshima was first presented by Haberstock et al. who employed the Munich AMS facility to measure {sup 36}Cl/Cl ratios in a gravestone from near the hypocenter. That work subsequently resulted in an expanded {sup 36}Cl effort in Germany that paralleled the US work. More recently, there have also been {sup 36}Cl measurements made by a Japanese

  13. Determination of the detection limit and decision threshold for ionizing radiation measurements. Part 3: Fundamentals and application to counting measurements by high resolution gamma spectrometry, without the influence of sample treatment

    International Nuclear Information System (INIS)

    2000-01-01

    This part of ISO 11929 addresses the field of ionizing radiation measurements in which events (in particular pulses) are counted by high resolution gamma spectrometry registrating a pulse-heights distribution (acquisition of a multichannel spectrum), for example on samples. It considers exclusively the random character of radioactive decay and of pulse counting and ignores all other influences (e.g. arising from sample treatment, weighing, enrichment or the instability of the test setup). It assumes that the distance of neighbouring peaks of gamma lines is not smaller than four times the full width half maximum (FWHM) of gamma line and that the background near to gamma line is nearly a straight line. Otherwise ISO 11929-1 or ISO 11929-2 should be used. ISO 11929 consists of the following parts, under the general title Determination of the detection limit and decision threshold for ionizing radiation measurements: Part 1: Fundamentals and application to counting measurements without the influence of sample treatment; Part 2: Fundamentals and application to counting measurements with the influence of sample treatment; Part 3: Fundamentals and application to counting measurements by high resolution gamma spectrometry, without the influence of sample treatment; Part 4: Fundamentals and application to measurements by use of linear scale analogue ratemeters, without the influence of sample treatment. This part of ISO 11929 was prepared in parallel with other International Standards prepared by WG2 (now WG 17): ISO 11932:1996, Activity measurements of solid materials considered for recycling, re-use or disposal as nonradioactive waste, and ISO 11929-1, ISO 11929-2 and ISO 11929-4, and is, consequently, complementary to these documents

  14. Validation of {sup 226}Ra, {sup 228}Ra and {sup 210}Pb measurements in soil and sediment samples through high resolution gamma ray spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Dias, Danila Carrijo da Silva; Silva, Nivaldo Carlos da; Bonifacio, Rodrigo Leandro; Guerrero, Eder Tadeu Zenun [Comissao Nacional de Energia Nuclear (LAPOC/CNEN-MG), Pocos de Caldas, MG (Brazil). Laboratorio de Pocos de Caldas

    2013-07-01

    Radionuclides found in ore extraction waste materials are a great source of concern regarding public health and environmental safety. One technique to determine the concentration of substances is high resolution gamma ray spectrometry using HPGe. Validating a measurement technique is essential to warrant high levels of quality to any scientific work. The Laboratory of Pocos de Caldas of the Brazilian Commission for Nuclear Energy partakes into a Quality Management System project, seeking Accreditation under ISO/IEC 17025 through the validation of techniques of chemical and radiometric analysis of environmental samples from water, soil and sediment. The focus of the Radon Laboratory at LAPOC is validation of Ra-226, Ra-228 and Pb-210 concentration determinations in soil and sediment through a gamma spectrometer system. The stages of this validation process included sample reception and preparation, detector calibration and sample analyses. Dried samples were sealed in metallic containers and analyzed after radioactive equilibrium between Ra-226 and daughters Pb-214 and Bi-214. Gamma spectrometry was performed using CANBERRA HPGe detector and gamma spectrum software Genie 2000. The photo peaks used for Ra-226 determination were 609 keV and 1020 keV of Bi-214 and 351 keV of Pb-214. For the Ra-228 determination a photopeak of 911 keV was used from its short half-life daughter Ac-228 (T1/2 = 6.12 h). For Pb-210, the photopeak of 46.5 keV was used, which, due to the low energy, self-absorption correction was needed. Parameters such as precision, bias/accuracy, linearity, detection limit and uncertainty were evaluated for that purpose. The results have pointed to satisfying results. (author)

  15. Validation of 226Ra, 228Ra and 210Pb measurements in soil and sediment samples through high resolution gamma ray spectrometry

    International Nuclear Information System (INIS)

    Dias, Danila Carrijo da Silva; Silva, Nivaldo Carlos da; Bonifacio, Rodrigo Leandro; Guerrero, Eder Tadeu Zenun

    2013-01-01

    Radionuclides found in ore extraction waste materials are a great source of concern regarding public health and environmental safety. One technique to determine the concentration of substances is high resolution gamma ray spectrometry using HPGe. Validating a measurement technique is essential to warrant high levels of quality to any scientific work. The Laboratory of Pocos de Caldas of the Brazilian Commission for Nuclear Energy partakes into a Quality Management System project, seeking Accreditation under ISO/IEC 17025 through the validation of techniques of chemical and radiometric analysis of environmental samples from water, soil and sediment. The focus of the Radon Laboratory at LAPOC is validation of Ra-226, Ra-228 and Pb-210 concentration determinations in soil and sediment through a gamma spectrometer system. The stages of this validation process included sample reception and preparation, detector calibration and sample analyses. Dried samples were sealed in metallic containers and analyzed after radioactive equilibrium between Ra-226 and daughters Pb-214 and Bi-214. Gamma spectrometry was performed using CANBERRA HPGe detector and gamma spectrum software Genie 2000. The photo peaks used for Ra-226 determination were 609 keV and 1020 keV of Bi-214 and 351 keV of Pb-214. For the Ra-228 determination a photopeak of 911 keV was used from its short half-life daughter Ac-228 (T1/2 = 6.12 h). For Pb-210, the photopeak of 46.5 keV was used, which, due to the low energy, self-absorption correction was needed. Parameters such as precision, bias/accuracy, linearity, detection limit and uncertainty were evaluated for that purpose. The results have pointed to satisfying results. (author)

  16. A method for determining the analytical form of a radionuclide depth distribution using multiple gamma spectrometry measurements

    Energy Technology Data Exchange (ETDEWEB)

    Dewey, Steven Clifford, E-mail: sdewey001@gmail.com [United States Air Force School of Aerospace Medicine, Occupational Environmental Health Division, Health Physics Branch, Radiation Analysis Laboratories, 2350 Gillingham Drive, Brooks City-Base, TX 78235 (United States); Whetstone, Zachary David, E-mail: zacwhets@umich.edu [Radiological Health Engineering Laboratory, Department of Nuclear Engineering and Radiological Sciences, University of Michigan, 2355 Bonisteel Boulevard, 1906 Cooley Building, Ann Arbor, MI 48109-2104 (United States); Kearfott, Kimberlee Jane, E-mail: kearfott@umich.edu [Radiological Health Engineering Laboratory, Department of Nuclear Engineering and Radiological Sciences, University of Michigan, 2355 Bonisteel Boulevard, 1906 Cooley Building, Ann Arbor, MI 48109-2104 (United States)

    2011-06-15

    When characterizing environmental radioactivity, whether in the soil or within concrete building structures undergoing remediation or decommissioning, it is highly desirable to know the radionuclide depth distribution. This is typically modeled using continuous analytical expressions, whose forms are believed to best represent the true source distributions. In situ gamma ray spectroscopic measurements are combined with these models to fully describe the source. Currently, the choice of analytical expressions is based upon prior experimental core sampling results at similar locations, any known site history, or radionuclide transport models. This paper presents a method, employing multiple in situ measurements at a single site, for determining the analytical form that best represents the true depth distribution present. The measurements can be made using a variety of geometries, each of which has a different sensitivity variation with source spatial distribution. Using non-linear least squares numerical optimization methods, the results can be fit to a collection of analytical models and the parameters of each model determined. The analytical expression that results in the fit with the lowest residual is selected as the most accurate representation. A cursory examination is made of the effects of measurement errors on the method. - Highlights: > A new method for determining radionuclide distribution as a function of depth is presented. > Multiple measurements are used, with enough measurements to determine the unknowns in analytical functions that might describe the distribution. > The measurements must be as independent as possible, which is achieved through special collimation of the detector. > Although the effects of measurements errors may be significant on the results, an improvement over other methods is anticipated.

  17. Carbon Isotope Measurements of Experimentally-Derived Hydrothermal Mineral-Catalyzed Organic Products by Pyrolysis-Isotope Ratio Mass Spectrometry

    Science.gov (United States)

    Socki, Richard A.; Fu, Qi; Niles, Paul B.

    2011-01-01

    We report results of experiments to measure the C isotope composition of mineral catalyzed organic compounds derived from high temperature and high pressure synthesis. These experiments make use of an innovative pyrolysis technique designed to extract and measure C isotopes. To date, our experiments have focused on the pyrolysis and C isotope ratio measurements of low-molecular weight intermediary hydrocarbons (organic acids and alcohols) and serve as a proof of concept for making C and H isotope measurements on more complicated mixtures of solid-phase hydrocarbons and intermediary products produced during high temperature and high pressure synthesis on mineral-catalyzed surfaces. The impetus for this work stems from recently reported observations of methane detected within the Martian atmosphere [1-4], coupled with evidence showing extensive water-rock interaction during Martian history [5-7]. Methane production on Mars could be the result of synthesis by mineral surface-catalyzed reduction of CO2 and/or CO by Fischer-Tropsch Type (FTT) reactions during serpentization reactions [8,9]. Others have conducted experimental studies to show that FTT reactions are plausible mechanisms for low-molecular weight hydrocarbon formation in hydrothermal systems at mid-ocean ridges [10-12]. Further, recent experiments by Fu et al. [13] focus on examining detailed C isotope measurements of hydrocarbons produced by surface-catalyzed mineral reactions. Work described in this paper details the experimental techniques used to measure intermediary organic reaction products (alcohols and organic acids).

  18. Hydrologic and geochemical controls on the transport of radionuclides in natural undisturbed arid environments as determined by accelerator mass spectrometry measurements. 1997 annual progress report

    International Nuclear Information System (INIS)

    Caffee, M.W.; Finkel, R.C.; McAninch, J.E.; Nimz, G.J.

    1997-01-01

    'During FY97 this study has developed unique accelerator mass spectrometry (AMS) analytical techniques for measurement of 99 Tc and 129 I, which compliments an improved capability for measurement of 36 Cl. The ability to measure these nuclides in natural soil samples has been demonstrated through analytical results obtained during FY97. Methods to determine the distribution of these nuclides in their natural setting, which will vary depending on site-specific chemical conditions, have also been developed. Spatially well-characterized soil samples have been collected from the vadose zone to a depth of -5 meters at the Nevada Test Site. To do this, a deep trench has been excavated and the geological setting for the soils has been well documented. Physical, chemical, and isotopic analysis of these soil samples during the course of this research project will result in a numerical computer model for moisture and radionuclide migration in arid soils that is valuable to nuclear waste storage, site remediation, and groundwater recharge concerns.'

  19. Measurement of CO{sub 2} and N{sub 2}O at nanomolar amounts using continuous-flow isotope-ratio mass spectrometry (CF-IRMS)

    Energy Technology Data Exchange (ETDEWEB)

    Patel, A; Downie, S.; Webster, E.; Hopkins, D.W.; Rennie, M.J. [Univ. of Dundee (United Kingdom)

    1994-12-01

    We are currently developing methods using Continuous Flow Isotope Ratio Mass Spectrometry (CF-IRMS) in conjunction with a thermal desorption purification unit to measure nanomolar levels of C0{sub 2} and N{sub 2}0. Samples of the pure gases diluted in He/air and transferred to septum capped Exetainers (Labco) provided a simple means to investigate the technique. We analyzed C0{sub 2} at natural abundance in the concentration range 50 to 5 nmoles and N{sub 2}0 at two concentrations between 25 and 5 nmoles. The technique was then used to measure C0{sub 2} (natural abundance and {sup 13}C-labeled) generated from the ninhydrin reaction. The results are summarized in a table; values are expressed in delta {sup 13}C notation relative to Pee Dee Belemnite. The data show that, provided care is taken to minimize or eliminate sources of contamination (air leaks, etc.), CF-IRMS coupled with a thermal desorption unit permits measurement of {sup 13}C enrichment in much smaller amounts of isolated amino acids than has been possible until now. The new methodology, including thermal desorption, should allow stable-isotope investigations on much smaller samples than are possible with other currently available techniques-while maintaining high precision.

  20. Quantifying uncertainty in the measurement of arsenic in suspended particulate matter by Atomic Absorption Spectrometry with hydride generator

    Directory of Open Access Journals (Sweden)

    Ahuja Tarushee

    2011-04-01

    Full Text Available Abstract Arsenic is the toxic element, which creates several problems in human being specially when inhaled through air. So the accurate and precise measurement of arsenic in suspended particulate matter (SPM is of prime importance as it gives information about the level of toxicity in the environment, and preventive measures could be taken in the effective areas. Quality assurance is equally important in the measurement of arsenic in SPM samples before making any decision. The quality and reliability of the data of such volatile elements depends upon the measurement of uncertainty of each step involved from sampling to analysis. The analytical results quantifying uncertainty gives a measure of the confidence level of the concerned laboratory. So the main objective of this study was to determine arsenic content in SPM samples with uncertainty budget and to find out various potential sources of uncertainty, which affects the results. Keeping these facts, we have selected seven diverse sites of Delhi (National Capital of India for quantification of arsenic content in SPM samples with uncertainty budget following sampling by HVS to analysis by Atomic Absorption Spectrometer-Hydride Generator (AAS-HG. In the measurement of arsenic in SPM samples so many steps are involved from sampling to final result and we have considered various potential sources of uncertainties. The calculation of uncertainty is based on ISO/IEC17025: 2005 document and EURACHEM guideline. It has been found that the final results mostly depend on the uncertainty in measurement mainly due to repeatability, final volume prepared for analysis, weighing balance and sampling by HVS. After the analysis of data of seven diverse sites of Delhi, it has been concluded that during the period from 31st Jan. 2008 to 7th Feb. 2008 the arsenic concentration varies from 1.44 ± 0.25 to 5.58 ± 0.55 ng/m3 with 95% confidence level (k = 2.

  1. Non-intrusive measurement of tritium activity in waste drums by modelling a 3He leak quantified by mass spectrometry

    International Nuclear Information System (INIS)

    Demange, D.

    2002-01-01

    This study deals with a new method that makes it possible to measure very low tritium quantities inside radioactive waste drums. This indirect method is based on measuring the decaying product, 3 He, and requires a study of its behaviour inside the drum. Our model considers 3 He as totally free and its leak through the polymeric joint of the drum as two distinct phenomena: permeation and laminar flow. The numerical simulations show that a pseudo-stationary state takes place. Thus, the 3 He leak corresponds to the tritium activity inside the drum but it appears, however, that the leak peaks when the atmospheric pressure variations induce an overpressure in the drum. Nevertheless, the confinement of a drum in a tight chamber makes it possible to quantify the 3 He leak. This is a non-intrusive measurement of its activity, which was experimentally checked by using reduced models, representing the drum and its confinement chamber. The drum's confinement was optimised to obtain a reproducible 3 He leak measurement. The gaseous samples taken from the chamber were purified using selective adsorption onto activated charcoals at 77 K to remove the tritium and pre-concentrate the 3 He. The samples were measured using a leak detector mass spectrometer. The adaptation of the signal acquisition and the optimisation of the analysis parameters made it possible to reach the stability of the external calibrations using standard gases with a 3 He detection limit of 0.05 ppb. Repeated confinement of the reference drums demonstrated the accuracy of this method. The uncertainty of this non-intrusive measurement of the tritium activity in 200-liter drums is 15% and the detection limit is about 1 GBq after a 24 h confinement. These results led to the definition of an automated tool able to systematically measure the tritium activity of all storage waste drums. (authors)

  2. Geomagnetic reversals, polar ice and cosmic spherules: some recent measurements with a small dedicated accelerator mass-spectrometry facility

    International Nuclear Information System (INIS)

    Raisbeck, G.M.; Yiou, F.

    1987-01-01

    We have developed techniques for measuring the cosmogenic isotopes 10 Be (half-life 1.5 Ma) and 26 Al (716 ka) by using a small (ca. 2.2 MV) dedicated accelerator mass spectrometer facility. Three recent applications of such measurements are as follows. 1. 10 Be has been measured in marine-sediment cores at levels corresponding to three recent geomagnetic reversals. We observe an increase in 10 Be production at each of these times. The results give information on the form and length of the geomagnetic intensity changes during a reversal, and the level at which magnetic remanence is acquired in the sediments. 2. 10 Be has been measured over a 2083 m ice core, corresponding to the last climatic cycle, recovered from Vostok, Antarctica. The results suggest that the precipitation rate during the last Ice Age was about half of its present rate. There are also some indications of fairly rapid 10 Be production changes. 3. 10 Be and 26 Al have been measured in 'cosmic spherules' (small round objects, ca. 500 μm diameter) recovered in deep-sea sediments and in melt lakes on Greenland ice. The results confirm an extraterrestrial origin for such objects, as well as indicating that the parent bodies of most of them were irradiated in space as small (less than 1 cm) objects. These spherules thus very probably represent cometary debris. (author)

  3. Ion mobility spectrometry as a simple and rapid method to measure the plasma propofol concentrations for intravenous anaesthesia monitoring

    Science.gov (United States)

    Wang, Xin; Zhou, Qinghua; Jiang, Dandan; Gong, Yulei; Li, Enyou; Li, Haiyang

    2016-11-01

    The plasma propofol concentration is important information for anaesthetists to monitor and adjust the anaesthesia depth for patients during a surgery operation. In this paper, a stand-alone ion mobility spectrometer (IMS) was constructed for the rapid measurement of the plasma propofol concentrations. Without any sample pre-treatment, the plasma samples were dropped on a piece of glass microfiber paper and then introduced into the IMS cell by the thermal desorption directly. Each individual measurement could be accomplished within 1 min. For the plasma propofol concentrations from 1 to 12 μg mL-1, the IMS response was linear with a correlation coefficient R2 of 0.998, while the limit of detection was evaluated to be 0.1 μg mL-1. These measurement results did meet the clinical application requirements. Furthermore, other clinically-often-used drugs, including remifentanil, flurbiprofen and atracurium, were found no significant interference with the qualitative and quantitative analysis of the plasma propofol. The plasma propofol concentrations measured by IMS were correlated well with those measured by the high performance liquid chromatography (HPLC). The results confirmed an excellent agreement between these two methods. Finally, this method was applied to monitor the plasma propofol concentrations for a patient undergoing surgery, demonstrating its capability of anaesthesia monitoring in real clinical environments.

  4. Measurement of cosmogenic 36Cl/Cl in young volcanic rocks: An application of accelerator mass spectrometry in geochronology

    International Nuclear Information System (INIS)

    Leavy, B.D.; Phillips, F.M.; Elmore, D.; Kubik, P.W.

    1987-01-01

    We have measured 36 Cl/Cl ratios in a number of young volcanic rocks in order to test the feasibility of using 36 Cl buildup as a geochronometer for materials less than about 700,000 years old. All of the analyzed rocks have been dated independently using K-Ar or other radiometric dating methods and have exposure histories that are known or can be reasonably assumed. Measured 36 Cl/Cl ratios in these rocks are in good agreement with the calculated in-situ 36 Cl buildup curve. These analyses indicate that AMS measurement of 36 Cl buildup in young rocks is a potentially powerful new method for dating materials that had previously been undatable, and as such will have broad applications in volcanology, tectonics, geophysics, and Quaternary research

  5. Mercury in Environmental and Biological Samples Using Online Combustion with Sequential Atomic Absorption and Fluorescence Measurements: A Direct Comparison of Two Fundamental Techniques in Spectrometry

    Science.gov (United States)

    Cizdziel, James V.

    2011-01-01

    In this laboratory experiment, students quantitatively determine the concentration of an element (mercury) in an environmental or biological sample while comparing and contrasting the fundamental techniques of atomic absorption spectrometry (AAS) and atomic fluorescence spectrometry (AFS). A mercury analyzer based on sample combustion,…

  6. Measurement of plasma vitamin K1 (phylloquinone) and K2 (menaquinones-4 and -7) using HPLC-tandem mass spectrometry

    NARCIS (Netherlands)

    Riphagen, Ineke J; van der Molen, Jan C; van Faassen, Martijn; Navis, Gerjan; de Borst, Martin H; Muskiet, Frits A J; de Jong, Wilhelmina H A; Bakker, Stephan J L; Kema, Ido P

    BACKGROUND: Given the growing interest in the health benefits of vitamin K, there is great need for development of new high-throughput methods for quantitative determination of vitamin K in plasma. We describe a simple and rapid method for measurement of plasma vitamin K1 (phylloquinone [PK]) and K2

  7. Improved accuracy and precision in δ15 NAIR measurements of explosives, urea, and inorganic nitrates by elemental analyzer/isotope ratio mass spectrometry using thermal decomposition.

    Science.gov (United States)

    Lott, Michael J; Howa, John D; Chesson, Lesley A; Ehleringer, James R

    2015-08-15

    Elemental analyzer systems generate N(2) and CO(2) for elemental composition and isotope ratio measurements. As quantitative conversion of nitrogen in some materials (i.e., nitrate salts and nitro-organic compounds) is difficult, this study tests a recently published method - thermal decomposition without the addition of O(2) - for the analysis of these materials. Elemental analyzer/isotope ratio mass spectrometry (EA/IRMS) was used to compare the traditional combustion method (CM) and the thermal decomposition method (TDM), where additional O(2) is eliminated from the reaction. The comparisons used organic and inorganic materials with oxidized and/or reduced nitrogen and included ureas, nitrate salts, ammonium sulfate, nitro esters, and nitramines. Previous TDM applications were limited to nitrate salts and ammonium sulfate. The measurement precision and accuracy were compared to determine the effectiveness of converting materials containing different fractions of oxidized nitrogen into N(2). The δ(13) C(VPDB) values were not meaningfully different when measured via CM or TDM, allowing for the analysis of multiple elements in one sample. For materials containing oxidized nitrogen, (15) N measurements made using thermal decomposition were more precise than those made using combustion. The precision was similar between the methods for materials containing reduced nitrogen. The %N values were closer to theoretical when measured by TDM than by CM. The δ(15) N(AIR) values of purchased nitrate salts and ureas were nearer to the known values when analyzed using thermal decomposition than using combustion. The thermal decomposition method addresses insufficient recovery of nitrogen during elemental analysis in a variety of organic and inorganic materials. Its implementation requires relatively few changes to the elemental analyzer. Using TDM, it is possible to directly calibrate certain organic materials to international nitrate isotope reference materials without off

  8. Comparison of serum testosterone and estradiol measurements in 3174 European men using platform immunoassay and mass spectrometry; relevance for the diagnostics in aging men.

    Science.gov (United States)

    Huhtaniemi, Ilpo T; Tajar, Abdelouahid; Lee, David M; O'Neill, Terence W; Finn, Joseph D; Bartfai, György; Boonen, Steven; Casanueva, Felipe F; Giwercman, Aleksander; Han, Thang S; Kula, Krzysztof; Labrie, Fernand; Lean, Michael E J; Pendleton, Neil; Punab, Margus; Silman, Alan J; Vanderschueren, Dirk; Forti, Gianni; Wu, Frederick C W

    2012-06-01

    The limitations of serum testosterone and estradiol (E(2)) measurements using non-extraction platform immunoassays (IAs) are widely recognized. Switching to more specific mass spectrometry (MS)-based methods has been advocated, but directly comparative data on the two methods are scarce. We compared serum testosterone and E(2) measurements in a large sample of middle-aged/elderly men using a common platform IA and a gas chromatography (GC)-MS method, in order to assess their limitations and advantages, and to diagnose male hypogonadism. Of subjects from the European Male Aging Study (n=3174; age 40-79 years), peripheral serum testosterone and E(2) were analyzed using established commercial platform IAs (Roche Diagnostics E170) and in-house GC-MS methods. Over a broad concentration range, serum testosterone concentration measured by IA and MS showed high correlation (R=0.93, PIA/MS correlation was weaker in E(2) measurements (R=0.32, P40.8 pmol/l, and R=0.74, P40.8 pmol/l). Using MS as the comparator method, IA ascertained low testosterone compatible with hypogonadism (IA for the detection of low E(2) (40.7 pmol/l) were 13.3 and 99.3%, and for high E(2) (>120 pmol/l) 88.4 and 88.6%. A validated platform IA is sufficient to detect subnormal testosterone concentrations in the diagnosis of male hypogonadism. The IA used for E(2) measurements showed poor correlation with MS and may only be suitable for the detection of high E(2) in men.

  9. Quantification and isotope ratio measurement of boron in U3Si2 by inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Saha, Abhijit; Deb, S.B.; Nagar, B.K.; Saxena, M.K.; Samanta, Papu

    2014-01-01

    An analytical methodology was developed for precise quantification and isotope ratio measurement of boron in U 3 Si 2 matrix by using ICP-MS after matrix separation. The analytical technique was validated by recovery studies employing standard addition method and the accuracy in isotope ratio measurement was improved by correcting the bias factor after analyzing NIST SRM951. The quantification of B in the three U 3 Si 2 samples was found in the range of 2.32-3.90 μg g -1 with a maximum standard deviation of 3%. The 10 B/ 11 B value in the three samples was found to be 0.2455±0.0042, 0.2451±0.0036 and 0.2452±0.0041. (author)

  10. {sup 53}Mn and {sup 60}Fe measurements in lunar samples by means of accelerator mass spectrometry (AMS)

    Energy Technology Data Exchange (ETDEWEB)

    Fimiani, Leticia; Faestermann, Thomas; Gomez Guzman, Jose Manuel; Hain, Karin; Korschinek, Gunther; Ludwig, Peter [Fakultaet fuer Physik, Technische Universitaet Muenchen, D-85748, Garching (Germany); Herzog, Gregory; Ligon, Bret; Park, Jisun [Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854 (United States); Knie, Klaus [GSI, Planckstrasse 1, D-64291, Darmstadt (Germany); Rugel, Georg [Fakultaet fuer Physik, Technische Universitaet Muenchen, D-85748, Garching (Germany); Forschungszentrum Dresden-Rossendorf, D-01314, Dresden (Germany)

    2012-07-01

    Cook et al, 40th LPSC 1129 (2009) reported a concentration of 14{sup +9}{sub -6} dpm {sup 60}Fe/[kg Ni] (T{sub 1/2}=2.62.10{sup 6}a) in a surface sample of the Apollo 12 12025/8 drive tube. This value is higher than the one expected due to galactic or solar cosmic ray production and may suggest the deposition of supernova debris on the lunar surface about 2 Ma ago. In order to try to reproduce this result, new measurements were made in material from the same core and position. To widen the search for supernova debris, we also analyzed four near-surface samples of lunar drive tube 15008; and one each from the skim, scoop and under-boulder samples 69921/41/61 via AMS in the Maier Leibnitz Laboratorium in Garching, Germany. The measuring technique and the preliminary results are discussed.

  11. Intercomparison measurements of surface soil contamination with in-situ gamma ray spectrometry. Pt.1. Artificial radionuclides

    International Nuclear Information System (INIS)

    Winkelmann, I.

    1994-01-01

    This intercomparison program was performed by the Federal Office of Radiation Protection in October 1993. It includes seven laboratory teams from five countries and is applied on a pasture in southern Germany having an undisturbed soil profile. The location was chosen because of its relatively high 137 Cs-soil contamination caused by the Chernobyl accident - up to 50 kBq/m 2 . The deposition of 134 Cs and 137 Cs was determined. The comparison demonstrated a good agreement between results from different labs. Additionally, the dose rate at all marked locations was measured and compared to the dose rate of individual radionuclides calculated from the measured spectra. A relatively good agreement was obtained. It is shown that the main contribution to the total dose rate of 70 nSv/h is made by 137 Cs with a value of 5 nSv/h. 4 figs., 2 tabs., 3 refs. (orig.)

  12. Portable gamma spectrometry: measuring soil erosion in-situ at four Critical Zone Observatories in P. R. China

    Science.gov (United States)

    Sanderson, N. K.; Green, S. M.; Chen, Z.; Wang, J.; Wang, Y.; Wang, R.; Yu, K.; Tu, C.; Jia, X.; Li, G.; Peng, X.; Quine, T. A.

    2017-12-01

    Detecting patterns of soil erosion, redistribution, and/soil nutrient loss is important for long-term soil conservation and agricultural sustainability. Caesium-137 (137Cs) and other fallout radionuclide inventories have been used over the the last 50 years to track soil erosion, transport and deposition on a catchment scale, and have been shown to be useful for informing models of temporal/spatial soil redistribution. Traditional sampling methods usually involves coring, grinding, sieving, sub-sampling and laboratory analysis using HPGe detectors, all of which can be costly and time consuming. In-situ measurements can provide a mechanism for assessment of 137Cs over larger areas that integrate the spatial variability, and expand turnover of analyses. Here, we assess the applicability of an in-situ approach based on radionuclide principles, and provide a comparison of the two approaches: laboratory vs. in-situ. The UK-China Critical Zone Observatory (CZO) programme provides an ideal research platform to assess the in-situ approach to measuring soil erosion: using a portable gamma spectrometer to determine 137Cs inventories. Four extensive field slope surveys were conducted in the CZO's, which covers four ecosystem types in China: karst, red soil, peri-urban, and loess plateau. In each CZO, 3-6 plots were measured along 2 slope transects, with 3 replicated 1 hour counts of 137Cs in each plot. In addition, 137Cs soil depth and bulk density profiles were also sampled for each plot, and lab-derived inventories calculated using traditional methods for comparison. Accurately and rapidly measuring 137Cs inventories using a portable field detector allows for a greater coverage of sampling locations and the potential for small-scale spatial integration, as well as the ability to re-visit sites over time and continually adapt and improve soil erosion/redistribution models, thus more effectively targeting areas of interest with reduced cost and time constraints.

  13. Development of a method to measure the concentration of 14C in the stack air of nuclear power plants by accelerator mass spectrometry (AMS)

    International Nuclear Information System (INIS)

    Stenstroem, K.; Erlandsson, B.; Hellborg, R.; Haakansson, K.; Wiebert, A.; Skog, G.

    1993-04-01

    C-14, a pure low-energetic beta-emitter, is produced through various nuclear reactions in nuclear power plants. Some of this C-14 is air-borne and is transported via the ventilation system through the stack of the power station and is integrated in living matter in the surroundings of the plant. The long half-life of the isotope (T1/2=5730 years) and the biological importance of carbon may lead to a not negligible contribution of the radiation dose for those living in the neighbourhood of nuclear power plants. C-14 has earlier been measured radiometrically with mainly two different methods, using proportional counters or liquid scintillators. In this report a new method is described, using an accelerator based technique. accelerator mass spectrometry (AMS). This technique has at least three advantages over the radiometrical methods. It requires only a few litres of gas per sample, which is 100-1000 times less compared to the radiometrical methods. It is insensitive to the beta and gamma rays from other radioactive isotopes in the stack air. The measuring time with AMS, about 20 minutes per sample, is considerably shorter compared to the radiometrical methods, which demand several hours per sample. The integrity of the AMS method is high and it might be convenient for regulatory supervision. (22 refs.)

  14. Hydrogen sulfide measurement by headspace-gas chromatography-mass spectrometry (HS-GC-MS): application to gaseous samples and gas dissolved in muscle.

    Science.gov (United States)

    Varlet, Vincent; Giuliani, Nicole; Palmiere, Cristian; Maujean, Géraldine; Augsburger, Marc

    2015-01-01

    The aim of our study was to present a new headspace-gas chromatography-mass spectrometry (HS-GC-MS) method applicable to the routine determination of hydrogen sulfide (H(2)S) concentrations in biological and gaseous samples. The primary analytical drawback of the GC/MS methods for H(2)S measurement discussed in the literature was the absence of a specific H(2)S internal standard required to perform quantification. Although a deuterated hydrogen sulfide (D(2)S) standard is currently available, this standard is not often used because this standard is expensive and is only available in the gas phase. As an alternative approach, D(2)S can be generated in situ by reacting deuterated chloride with sodium sulfide; however, this technique can lead to low recovery yield and potential isotopic fractionation. Therefore, N(2)O was chosen for use as an internal standard. This method allows precise measurements of H(2)S concentrations in biological and gaseous samples. Therefore, a full validation using accuracy profile based on the β-expectation tolerance interval is presented. Finally, this method was applied to quantify H(2)S in an actual case of H(2)S fatal intoxication. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  15. Measurement of the redistribution of arsenic at nickel silicide/silicon interface by secondary ion mass spectrometry: artifact and optimized analysis conditions

    International Nuclear Information System (INIS)

    Hoummada, K.; Mangelinck, D.; Perrin, C.; Carron, V.; Holliger, P.

    2008-01-01

    The arsenic redistribution after NiSi formation has been measured by secondary ion mass spectrometry (SIMS). The NiSi film has been obtained by solid state reaction of a Ni thin film with a silicon substrate doped with As. An increase in the As SIMS signal at the NiSi/Si interface was observed for some experimental conditions. By varying the SIMS experimental parameters (incidence angle and the impact energy), the As signal at NiSi/Si interface was found to change. The SIMS experimental parameters have been optimized and were found to be an impact energy of 1 keV and an incidence angle superior to 50 deg. This allows us to minimize differences in sputtering rate and ion yield between NiSi and Si and to obtain a good depth resolution and dynamic range. Under these conditions the bump in the As signal does not appear: this illustrates the difficulty to measure concentration at interface by SIMS

  16. Coupling between chip based isotachophoresis and multi-collector inductively coupled plasma mass spectrometry for separation and measurement of lanthanides

    International Nuclear Information System (INIS)

    Vio, Laurent; Cretier, Gerard; Rocca, Jean-Louis; Chartier, Frederic; Geertsen, Valerie; Gourgiotis, Alkiviadis; Isnard, Helene; Morin, Pierre

    2012-01-01

    This paper presents the conception and fabrication of a micro-system for lanthanides separation and its coupling with a multi-collector inductively coupled plasma mass spectrometer for isotope ratio measurements. The lanthanides separation is based on the isotachophoresis technique and the micro-system conception has been adapted in order to fit with glove box limitations in view of future spent nuclear fuels analysis. The micro-device was tested by using a mixture of standard solutions of natural elements and the separation of 13 lanthanides was successfully performed. The micro-device was then coupled to a multi-collector inductively coupled plasma mass spectrometer for the on-line measurements of Nd and Sm isotope ratios. The isotopes of Nd and Sm were acquired online in multi-collection mode after separation of the two elements with an injection amount of 5 ng. Results obtained on the Nd and Sm isotope ratio measurements on transient signals are presented and discussed. (authors)

  17. Classifying wine according to geographical origin via quadrupole-based ICP-mass spectrometry measurements of boron isotope ratios

    Energy Technology Data Exchange (ETDEWEB)

    Coetzee, Paul P. [University of Johannesburg, Department of Chemistry, Johannesburg (South Africa); Vanhaecke, Frank [Institute for Nuclear Sciences, Laboratory of Analytical Chemistry Ghent University, Ghent (Belgium)

    2005-11-01

    The potential of quadrupole-based ICP-MS as a tool for B-isotopic analysis of wines and its usefulness in provenance determinations were assessed. A precision of 0.1-0.25% RSD (corresponding to a relative standard deviation of the mean of three replicate measurements of 0.06-0.12%) was sufficient to establish small differences in the B isotope ratios in wines from different geographical origins. Each sample measurement was bracketed by measurements of a standard and mass bias drift correction made by interpolation. Sample preparation was kept to a minimum to avoid possible fractionation. Dilution of the wine samples by a factor of 100 with 0.65% HNO{sub 3} was found to reduce matrix-induced mass discrimination substantially. Wines from three wine-producing regions, Stellenbosch, Robertson, and Swartland, in the Western Cape Province of South Africa, and wines from specific regions in France (Bergerac) and Italy (Valpolicella) were analyzed by ICP-QMS for their B-isotopic compositions. It was concluded that the {sup 11}B/{sup 10}B ratios can be used to characterize wines from different geographical origins. Average {sup 11}B/{sup 10}B ratios in red wines from South Africa (Stellenbosch), France (Bergerac), and Italy (Valpolicella) were found to differ by between 0.5 and 1.5%. (orig.)

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

    Science.gov (United States)

    Ohata, Masaki; Kidokoro, Toshihiro; Hioki, Akiharu

    2012-01-01

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

  19. Measurement of natural radioactivity in building materials of Namakkal, Tamil Nadu, India using gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Ravisankar, R.; Vanasundari, K.; Chandrasekaran, A.; Rajalakshmi, A.; Suganya, M.; Vijayagopal, P.; Meenakshisundaram, V.

    2012-01-01

    The natural level of radioactivity in building materials is one of the major causes of external exposure to γ-rays. The primordial radionuclides in building materials are one of the sources of radiation hazard in dwellings made of these materials. By the determination of the radioactivity level in building materials, the indoor radiological hazard to human health can be assessed. This is an important precautionary measure whenever the dose rate is found to be above the recommended limits. The aim of this work was to measure the specific activity concentration of 226 Ra, 232 Th and 40 K in commonly used building materials from Namakkal, Tamil Nadu, India, using gamma-ray spectrometer. The radiation hazard due to the total natural radioactivity in the studied building materials was estimated by different approaches. The concentrations of the natural radionuclides and the radium equivalent activity in studied samples were compared with the corresponding results of different countries. From the analysis, it is found that these materials may be safely used as construction materials and do not pose significant radiation hazards. - Highlights: ► Most of the building materials contain natural radionuclides. ► The radioactivity level in building materials is used to assess the radiological hazards to human. ► We present the results for the measured activities and radiation hazards of building materials. ► We report that the studied building materials do not pose any significant radiation hazard.

  20. The measurement of activities of 226Ra, 232Th, 40K in phosphogypsum by gamma ray spectrometry

    International Nuclear Information System (INIS)

    Parmaksiz, A.

    2004-06-01

    Phosphatic fertilizers are produced from the industrial processing of rock phosphate ores which are known to contain naturally occuring radionuclides such as 238 U and its daughter products. A high volume by-product known as phosphogypsum (PG) from the production of phosphoric acid and phosphate fertilizer causes serious storage and environmental problems in phosphoric acid industries. During the phosphoric acid production process, 226 Ra (t 1/2 =1600 y) ends up in PG which has chemical analogous to calcium periodical table. Since the stockpiles of PG near the phosphatic fertilizer plants are huge amounts, the radioactivity contained in PG has to measured in view of environmental radioactivity problem. In this work, the natural radioactivity in eighty PG samples, issued from a stock of about 60.000 tones was measured by a high resolution gamma ray spectrometer with a HPGe detector. The averaged activity of 226 Ra in PG has been found to be 546 Bq.kg -1 . However, the activities of 232 Th and 40 K measured in PG samples are negligibly small. The extra gamma radiation dose rate arising from 1 - 1.5 kg of PG is estimated to be about 241 nGy/h from 1 m ground level applied in 1 m 2 surface area of field

  1. Classifying wine according to geographical origin via quadrupole-based ICP-mass spectrometry measurements of boron isotope ratios

    International Nuclear Information System (INIS)

    Coetzee, Paul P.; Vanhaecke, Frank

    2005-01-01

    The potential of quadrupole-based ICP-MS as a tool for B-isotopic analysis of wines and its usefulness in provenance determinations were assessed. A precision of 0.1-0.25% RSD (corresponding to a relative standard deviation of the mean of three replicate measurements of 0.06-0.12%) was sufficient to establish small differences in the B isotope ratios in wines from different geographical origins. Each sample measurement was bracketed by measurements of a standard and mass bias drift correction made by interpolation. Sample preparation was kept to a minimum to avoid possible fractionation. Dilution of the wine samples by a factor of 100 with 0.65% HNO 3 was found to reduce matrix-induced mass discrimination substantially. Wines from three wine-producing regions, Stellenbosch, Robertson, and Swartland, in the Western Cape Province of South Africa, and wines from specific regions in France (Bergerac) and Italy (Valpolicella) were analyzed by ICP-QMS for their B-isotopic compositions. It was concluded that the 11 B/ 10 B ratios can be used to characterize wines from different geographical origins. Average 11 B/ 10 B ratios in red wines from South Africa (Stellenbosch), France (Bergerac), and Italy (Valpolicella) were found to differ by between 0.5 and 1.5%. (orig.)

  2. All-silicon Michelson instrument on chip: Distance and surface profile measurement and prospects for visible light spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Malak, M.; Marty, F.; Bourouina, T. [Universite Paris-Est, Laboratoire ESYCOM, ESIEE Paris, Cite Descartes, 2 Boulevard Blaise Pascal, 93162 Noisy-le-Grand Cedex (France); Nouira, H.; Vailleau, G. [Laboratoire National de Metrologie et d' Essais, 1 rue Gaston Boissier, 75724 Paris Cedex 15 (France)

    2013-04-08

    A miniature Michelson interferometer is analyzed theoretically and experimentally. The fabricated micro-interferometer is incorporated at the tip of a monolithic silicon probe to achieve contactless distance measurements and surface profilometry. For infrared operation, two approaches are studied, based on the use of monochromatic light and wavelength sweep, respectively. A theoretical model is devised to depict the system characteristics taking into account Gaussian beam divergence and light spot size. Furthermore, preliminary results using visible light demonstrate operation of the probe as a visible light spectrometer, despite silicon absorbance, thanks to the micrometer thickness involved in the beam splitter.

  3. All-silicon Michelson instrument on chip: Distance and surface profile measurement and prospects for visible light spectrometry

    International Nuclear Information System (INIS)

    Malak, M.; Marty, F.; Bourouina, T.; Nouira, H.; Vailleau, G.

    2013-01-01

    A miniature Michelson interferometer is analyzed theoretically and experimentally. The fabricated micro-interferometer is incorporated at the tip of a monolithic silicon probe to achieve contactless distance measurements and surface profilometry. For infrared operation, two approaches are studied, based on the use of monochromatic light and wavelength sweep, respectively. A theoretical model is devised to depict the system characteristics taking into account Gaussian beam divergence and light spot size. Furthermore, preliminary results using visible light demonstrate operation of the probe as a visible light spectrometer, despite silicon absorbance, thanks to the micrometer thickness involved in the beam splitter.

  4. Sensitive measurement of serum 1α,25-dihydroxyvitamin D by liquid chromatography/tandem mass spectrometry after removing interference with immunoaffinity extraction.

    Science.gov (United States)

    Yuan, Chao; Kosewick, Justin; He, Xiang; Kozak, Marta; Wang, Sihe

    2011-05-15

    Vitamin D plays important roles in bone health and a variety of other pathophysiological conditions. 1α,25-Dihydroxyvitamin D is the active form of vitamin D. Quantification of serum 1α,25-dihydroxyvitamin D is useful for evaluation of several diseases including chronic renal failure, hypoparathyroidism, sarcoidosis, and rickets. Measurement of 1α,25-dihydroxyvitamin D is very challenging due to its low circulating concentration and presence of interfering substances in serum. In this report, a liquid chromatography/tandem mass spectrometry (LC/MS/MS) method for quantifying serum 1α,25-dihydroxyvitamin D is described. Lithium adducts of 1α,25-dihydroxyvitamin D were formed prior to mass spectrometry analysis to improve ionization efficiency. We tested a number of different sample preparation procedures and found that immunoaffinity extraction was the method of choice because it completely removed isobaric interferences and matrix effects present in patient serum. Extraction efficiency, expressed as absolute recovery, was greater than 60% in both patient serum and charcoal-stripped serum. This method was linear from 3.4 to 206.2 pg/mL for 1α,25-dihydroxyvitamin D(3) and 3.9 to 212.6 pg/mL for 1α,25-dihydroxyvitamin D(2) with an accuracy of 89.8-98.4% and 97.5-115.7%, respectively. Inter-assay and intra-assay coefficients of variance (CVs) for both analytes at two different concentration levels ranged from 2.5-7.0%. Comparison with a radioimmunoassay for measuring total 1α,25-dihydroxyvitamin D concentration using 40 patient samples showed a Deming regression slope of 0.751, a y-intercept of 0.84 pg/mL, an r value of 0.7909, and a mean percentage difference of -27.1%. Comparison with a reference LC/MS/MS method (n = 20) showed a Deming regression slope of 1.020, a y-intercept of 1.32 pg/mL, an r value of 0.9797, and a mean percentage difference of -2.9%. In conclusion, usage of immunoaffinity extraction enabled a sensitive LC/MS/MS method for

  5. Measurement of δ18O, δ17O, and 17O-excess in Water by Off-Axis Integrated Cavity Output Spectroscopy and Isotope Ratio Mass Spectrometry

    Science.gov (United States)

    Berman, Elena S.F.; Levin, Naomi E.; Landais, Amaelle; Li, Shuning; Owano, Thomas

    2013-01-01

    Stable isotopes of water have long been used to improve understanding of the hydrological cycle, catchment hydrology, and polar climate. Recently, there has been increasing interest in measurement and use of the less-abundant 17O isotope in addition to 2H and 18O. Off-axis integrated cavity output spectroscopy (OA-ICOS) is demonstrated for accurate and precise measurements δ18O, δ17O, and 17O-excess in liquid water. OA-ICOS involves no sample conversion and has a small footprint, allowing measurements to be made by researchers collecting the samples. Repeated (514) high-throughput measurements of the international isotopic reference water standard GISP demonstrate the precision and accuracy of OA-ICOS: δ18OVSMOW-SLAP =−24.74 ± 0.07 ‰ (1σ) and δ17OVSMOW-SLAP = −13.12 ± 0.05 ‰ (1σ). For comparison, the IAEA value for δ18OVSMOW-SLAP is −24.76 ± 0.09 ‰ (1σ) and an average of previously reported values for δ17OVSMOW-SLAP is −13.12 ± 0.06 ‰ (1σ). Multiple (26) high-precision measurements of GISP provide a 17O-excessVSMOW-SLAP of 23 ± 10 per meg (1σ); an average of previously reported values for 17O-excessVSMOW-SLAP is 22 ± 11 per meg (1σ). For all these OA-ICOS measurements, precision can be further enhanced by additional averaging. OA-ICOS measurements were compared with two independent isotope ratio mass spectrometry (IRMS) laboratories and shown to have comparable accuracy and precision as the current fluorination-IRMS techniques in δ18O, δ17O, and 17O-excess. The ability to measure accurately δ18O, δ17O, and 17O-excess in liquid water inexpensively and without sample conversion is expected to increase vastly the application of δ17O and 17O-excess measurements for scientific understanding of the water cycle, atmospheric convection, and climate modeling among others. PMID:24032448

  6. Ratiometric measurements of adiponectin by mass spectrometry in bottlenose dolphins (Tursiops truncatus with iron overload reveal an association with insulin resistance and glucagon

    Directory of Open Access Journals (Sweden)

    Benjamin A Neely

    2013-09-01

    Full Text Available High molecular weight (HMW adiponectin levels are reduced in humans with type 2 diabetes and insulin resistance. Similar to humans with insulin resistance, managed bottlenose dolphins (Tursiops truncatus diagnosed with hemochromatosis (iron overload have higher levels of 2 h post-prandial plasma insulin than healthy controls. A parallel reaction monitoring assay for dolphin serum adiponectin was developed based on tryptic peptides identified by mass spectrometry. Using identified post-translational modifications, a differential measurement was constructed. Total and unmodified adiponectin levels were measured in sera from dolphins with (n=4 and without (n=5 iron overload. This measurement yielded total adiponectin levels as well as site specific percent unmodified adiponectin that may inversely correlate with HMW adiponectin. Differences in insulin levels between iron overload cases and controls were observed 2 h post-prandial, but not during the fasting state. Thus, post-prandial as well as fasting serum adiponectin levels were measured to determine whether adiponectin and insulin would follow similar patterns. There was no difference in total adiponectin or percent unmodified adiponectin from case or control fasting animals. There was no difference in post-prandial total adiponectin levels between case and control dolphins (mean ± S.D. at 763 ± 298 and 727 ± 291 pmol/ml, respectively (p = 0.91; however, percent unmodified adiponectin was significantly higher in post-prandial cases compared controls (30.0 ± 6.3 versus 17.0 ± 6.6%, respectively; p = 0.016. Interestingly, both total and percent unmodified adiponectin were correlated with glucagon levels in controls (r = 0.999, p < 0.001, but not in cases, which is possibly a reflection of insulin resistance. Although total adiponectin levels were not significantly different, the elevated percent unmodified adiponectin follows a trend similar to HMW adiponectin reported for humans with

  7. Forensic analysis of explosives using isotope ratio mass spectrometry (IRMS)--part 1: instrument validation of the DELTAplusXP IRMS for bulk nitrogen isotope ratio measurements.

    Science.gov (United States)

    Benson, Sarah J; Lennard, Christopher J; Hill, David M; Maynard, Philip; Roux, Claude

    2010-01-01

    A significant amount of research has been conducted into the use of stable isotopes to assist in determining the origin of various materials. The research conducted in the forensic field shows the potential of isotope ratio mass spectrometry (IRMS) to provide a level of discrimination not achievable utilizing traditional forensic techniques. Despite the research there have been few, if any, publications addressing the validation and measurement uncertainty of the technique for forensic applications. This study, the first in a planned series, presents validation data for the measurement of bulk nitrogen isotope ratios in ammonium nitrate (AN) using the DELTA(plus)XP (Thermo Finnigan) IRMS instrument equipped with a ConFlo III interface and FlashEA 1112 elemental analyzer (EA). Appropriate laboratory standards, analytical methods and correction calculations were developed and evaluated. A validation protocol was developed in line with the guidelines provided by the National Association of Testing Authorities, Australia (NATA). Performance characteristics including: accuracy, precision/repeatability, reproducibility/ruggedness, robustness, linear range, and measurement uncertainty were evaluated for the measurement of nitrogen isotope ratios in AN. AN (99.5%) and ammonium thiocyanate (99.99+%) were determined to be the most suitable laboratory standards and were calibrated against international standards (certified reference materials). All performance characteristics were within an acceptable range when potential uncertainties, including the manufacturer's uncertainty of the technique and standards, were taken into account. The experiments described in this article could be used as a model for validation of other instruments for similar purposes. Later studies in this series will address the more general issue of demonstrating that the IRMS technique is scientifically sound and fit-for-purpose in the forensic explosives analysis field.

  8. Description of analytical method and clinical utility of measuring serum 7-alpha-hydroxy-4-cholesten-3-one (7aC4) by mass spectrometry.

    Science.gov (United States)

    Donato, Leslie J; Lueke, Alan; Kenyon, Stacy M; Meeusen, Jeffrey W; Camilleri, Michael

    2018-02-01

    Imbalance of bile acids (BA) homeostasis in the gastrointestinal tract can lead to chronic diarrhea or constipation when BA in the colon are in excess or low, respectively. Since both disturbances of bowel function can result from other etiologies, identifying BA imbalance is important to tailor treatment strategies. Serum concentrations of 7-alpha-hydroxy-4-cholesten-3-one (7aC4), a precursor in bile acid synthesis, reflect BA homeostasis. Here we describe a method to accurately measure serum 7aC4 and evaluate the clinical utility in patients with diarrhea or constipation phenotypes. Serum 7aC4 is measured after acetonitrile protein precipitation using C18 liquid chromatography, tandem mass spectrometry, and deuterium-labeled 7aC4 internal standard. Assay performance including linearity, precision, and accuracy was assessed using waste serum samples. The reference interval was established in healthy individuals without BA-altering conditions or medications. Clinical performance was assessed in patients with irritable bowel syndrome. The method precisely and accurately measured 7aC4 in human serum from 1.4-338ng/mL with no ion suppression or interference from related 7-keto-cholesterol. Central 95th percentile reference interval was 2.5-63.2ng/mL. Lower serum 7aC4 was found in patients with constipation with sensitivity/specificity of 79%/55% compared to healthy controls. Higher 7aC4 was found in patients with bile acid diarrhea (BAD) compared to those without BAD with sensitivity/specificity of 82%/53%. We have developed a sensitive and precise assay for measuring the concentration of 7aC4 in serum. The assay can be used to screen for diarrhea caused by bile acid malabsorption. Copyright © 2017 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  9. Measurement of {sup 14}C time scale of the rings of a tree by accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Oda, Hirotaka; Furukawa, Michiaki [Nagoya Univ. (Japan). School of Science; Yonenobu, Hitoshi; Ikeda, Akiko; Nakamura, Toshio

    1996-12-01

    {sup 14}C time scale is different from a histrical data in order that it is calculated by assuming that the concentration of {sup 14}C in the sample has not been changed by age. The object of this work is to make clear the errors in measurement of {sup 14}C time scale of the ring of a tree known the tree age. The every year ring of a Hinoki in Kiso, 950 years old, was used as a sample. The most external ring is determined as 1923 years old on the basis of the dendrochronology. The rings after 1120 years were used as the samples. {alpha}-cellulose, the most stable component in the structural components of cell of tree, was prepared from each ring. About 8 mg of {alpha}-cellulose was reduced to graphite to be measured by the tandem thoron analytic meter. The results obtained showed that {sup 14}C time scale was older than that of the histrical data in the twelfth and thirteenth century, but it was more new than that of the histrical data from the late seventeenth to the middle of eighteenth century. The results were agreement with that of Stuiver and Pearson (1933). (S.Y.)

  10. Virtual disjunct eddy covariance measurements of organic compound fluxes from a subalpine forest using proton transfer reaction mass spectrometry

    Directory of Open Access Journals (Sweden)

    T. G. Karl

    2002-01-01

    Full Text Available A `virtual' disjunct eddy covariance (vDEC device was tested with field measurements of biogenic VOC fluxes at a subalpine forest site in the Rocky Mountains of the USA. A PTR-MS instrument was used as the VOC sensor. Daily peak emission fluxes of 2-methyl-3-buten-2-ol (MBO, methanol, acetone and acetaldehyde were around 1.5, 1, 0.8 and 0.4 mg m-2 h-1, respectively. High pass filtering due to long sampling lines was investigated in laboratory experiments, and suggested that VOC losses in PTFA lines are generally governed by diffusion laws. Memory effects and surface reactions did not seem to play a dominant role. Model estimates of MBO fluxes compared well with measured fluxes. The results also suggest that latent heat and sensible heat fluxes are reasonably well correlated with VOC fluxes and could be used to predict variations in VOC emissions. The release of MBO, methanol, acetone and acetaldehyde resulted in significant change of tropospheric oxidant levels and a 10--40% increase in ozone levels, as inferred from a photochemical box model. We conclude that vDEC with a PTR-MS instrument is a versatile tool for simultaneous field analysis of multiple VOC fluxes.

  11. Measurement of natural radioactivity in building materials of Namakkal, Tamil Nadu, India using gamma-ray spectrometry.

    Science.gov (United States)

    Ravisankar, R; Vanasundari, K; Chandrasekaran, A; Rajalakshmi, A; Suganya, M; Vijayagopal, P; Meenakshisundaram, V

    2012-04-01

    The natural level of radioactivity in building materials is one of the major causes of external exposure to γ-rays. The primordial radionuclides in building materials are one of the sources of radiation hazard in dwellings made of these materials. By the determination of the radioactivity level in building materials, the indoor radiological hazard to human health can be assessed. This is an important precautionary measure whenever the dose rate is found to be above the recommended limits. The aim of this work was to measure the specific activity concentration of (226)Ra, (232)Th and (40)K in commonly used building materials from Namakkal, Tamil Nadu, India, using gamma-ray spectrometer. The radiation hazard due to the total natural radioactivity in the studied building materials was estimated by different approaches. The concentrations of the natural radionuclides and the radium equivalent activity in studied samples were compared with the corresponding results of different countries. From the analysis, it is found that these materials may be safely used as construction materials and do not pose significant radiation hazards. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. High precision measurement by mass spectrometry of isotopic ratios δ13C and δ18O of carbon dioxide

    International Nuclear Information System (INIS)

    Bourg, Chr.; Ciais, Ph.

    1998-02-01

    Carbon dioxide (CO 2 ) is the second natural greenhouse gas in the Earth's atmosphere, after vapor water. Its concentration levels have been increasing by 25% due to human activities over the past 200 years, thus increasing the radiative forcing at the surface and potentially including major climate change for the next centuries. It is of primary importance to better quantify the role of carbon contained into the oceans and the land biota in moderating the anthropic perturbation. To do so, 13 C and 18 O isotopes are unique tools which allow to estimate indirectly the terrestrial CO 2 fluxes based on atmospheric measurements. The present reports describes the experimental set-up used at the CFR-LMCE laboratory to measure the 13 C and 18 O natural abundance in atmospheric carbon dioxide. This technique requires high levels of both precision and accuracy because the geochemical signal nevertheless consists of very small changes in isotopic composition (on the order of 0.01 permits). Also, given the large number of samples to analyses routinely, it must be run in an automatic mode. Our experiment design consists of 'extraction line' where CO 2 is separated cryogenically from the air, which is coupled to a (Finnigan MAT 252) mass spectrometer. (authors)

  13. Online measurement of biogenic organic acids in the boreal forest using atmospheric pressure chemical ionization mass spectrometry (APCI-MS)

    Science.gov (United States)

    Vogel, A. L.; Brüggemann, M.; ńijälä, M.; Ehn, M.; Junninen, H.; Corrigan, A. L.; Petäjä, T.; Worsnop, D. R.; Russell, L. M.; Kulmala, M.; Williams, J.; Hoffmann, T.

    2012-04-01

    Emission of biogenic volatile organic compounds (BVOCs) by vegetation in the boreal forest and their subsequent atmospheric oxidation leads to the formation of secondary organic aerosol (SOA) which has important impacts on climate and human health. Oxidation of BVOCs produces a variety of mostly unidentified species in oxygenated organic aerosol (OOA). Presently aerosol mass spectrometers (AMS) are able to determine quantitative information about the relative oxygen to carbon content of organic aerosols and thereby reveal the photochemical age and volatility of organic aerosol by distinguishing between low volatile oxygenated organic aerosol (LV-OOA), semivolatile oxygenated organic aerosol (SV-OOA) and hydrocarbon like organic aerosol (HOA)[1]. However, the AMS can usually not be used to measure and quantify single organic compounds such as individual biogenic organic marker compounds. Here we show the results of online measurements of gas and particle phase biogenic acids during HUMPPA-COPEC 2010 at Hyytiälä, Finland. This was achieved by coupling a self built miniature Versatile Aerosol Concentration Enrichment System (mVACES) as described by Geller et al. [2] with an Atmospheric Pressure Chemical Ionization Ion Trap Mass Spectrometer (APCI IT MS; Hoffmann et al., [3]). The benefits of the on-line APCI-MS are soft ionization with little fragmentation compared to AMS, high measurement frequency and less sampling artifacts than in the common procedure of taking filter samples, extraction and detection with LC-MS. Furthermore, the ion trap of the instrument allows MS/MS experiments to be performed by isolation of single m/z ratios of selected molecular species. By subsequent addition of energy, the trapped ions form characteristic fragments which enable structural insight on the molecular level. Comparison of APCI-MS data to AMS data, acquired with a C-ToF-AMS [4], revealed a good correlation coefficient for total organics and sulphate. Furthermore, data show

  14. UPLC-MRM Mass Spectrometry Method for Measurement of the Coagulation Inhibitors Dabigatran and Rivaroxaban in Human Plasma and Its Comparison with Functional Assays.

    Directory of Open Access Journals (Sweden)

    Joachim Kuhn

    Full Text Available The fast, precise, and accurate measurement of the new generation of oral anticoagulants such as dabigatran and rivaroxaban in patients' plasma my provide important information in different clinical circumstances such as in the case of suspicion of overdose, when patients switch from existing oral anticoagulant, in patients with hepatic or renal impairment, by concomitant use of interaction drugs, or to assess anticoagulant concentration in patients' blood before major surgery.Here, we describe a quick and precise method to measure the coagulation inhibitors dabigatran and rivaroxaban using ultra-performance liquid chromatography electrospray ionization-tandem mass spectrometry in multiple reactions monitoring (MRM mode (UPLC-MRM MS. Internal standards (ISs were added to the sample and after protein precipitation; the sample was separated on a reverse phase column. After ionization of the analytes the ions were detected using electrospray ionization-tandem mass spectrometry. Run time was 2.5 minutes per injection. Ion suppression was characterized by means of post-column infusion.The calibration curves of dabigatran and rivaroxaban were linear over the working range between 0.8 and 800 μg/L (r >0.99. Limits of detection (LOD in the plasma matrix were 0.21 μg/L for dabigatran and 0.34 μg/L for rivaroxaban, and lower limits of quantification (LLOQ in the plasma matrix were 0.46 μg/L for dabigatran and 0.54 μg/L for rivaroxaban. The intraassay coefficients of variation (CVs for dabigatran and rivaroxaban were < 4% and 6%; respectively, the interassay CVs were < 6% for dabigatran and < 9% for rivaroxaban. Inaccuracy was < 5% for both substances. The mean recovery was 104.5% (range 83.8-113.0% for dabigatran and 87.0% (range 73.6-105.4% for rivaroxaban. No significant ion suppressions were detected at the elution times of dabigatran or rivaroxaban. Both coagulation inhibitors were stable in citrate plasma at -20°C, 4°C and even at RT for at

  15. Measurement of the metabolic interconversion of deuterium-labeled fatty acids by gas chromatography/mass spectrometry

    International Nuclear Information System (INIS)

    Rohwedder, W.K.; Duval, S.M.; Wolf, D.J.; Emken, E.A.

    1990-01-01

    An analytical method that was developed to analyze deuterium-labeled fatty acids in human blood has been extended to identify labeled fatty acids from C14 to C24 chain length which are formed by metabolic processes such as desaturation, elongation, or shortening of the labeled fatty acids fed. A new computer and a hardware adder have been utilized to assure reliable data acquisition. Relative standard deviations for the analysis of labeled fatty acids were measured at 0.02, 0.03, and 0.04 at the 5%, 1%, and 0.2% levels of the labeled fatty acid methyl esters, respectively. The method makes extensive use of standards and computer processing for accuracy and high productivity. Data from a chylomicron triacylglycerol fraction are included to demonstrate the sensitivity of detection of metabolites formed by desaturation and elongation

  16. A high precision mass spectrometry method for measuring O2/N2 ratios and CO2 concentrations in air

    International Nuclear Information System (INIS)

    Marca, A.D.; Dennis, P.F.; Etchells, A.

    2002-01-01

    A full, detailed understanding of the global carbon budget is needed for robust modelling of global climate and environmental change. Since the industrial revolution the carbon cycle has been shifted from a steady state in which removal of CO 2 from the atmosphere through photosynthesis is balanced by its addition through respiration. Currently increased respiration due to deforestation, modern agricultural practises and the burning of fossil fuels dominates photosynthesis resulting in modern atmospheric CO 2 concentrations some 32% higher than the year 1800 levels. However, the CO 2 concentration rises are lower than expected from known fossil fuel combustion inventories. A significant proportion of the excess CO 2 is taken up by the oceans, however a missing carbon sink must still be invoked to account for the difference between measured and expected CO 2 rises. A global greening as a result of increased photosynthesis is required to close the circle

  17. Measurement of long-lived radionuclides in surface soil around F1NPP accident site by Accelerator Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Miyake, Yasuto; Matsuzaki, Hiroyuki [Department of Nuclear Engineering and Management, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo (Japan); Sasa, Kimikazu; Takahashi, Tsutomu [AMS Group, Tandem Accelerator Complex, Research Facility Center for Science and Technology, University of Tsukuba, Tsukuba, Ibaraki 305-8577 (Japan)

    2015-10-15

    In March 2011, vast amounts of radionuclides were released into the environment due to the Fukushima Daiichi Nuclear Power Plant (F1NPP) accident. However, very little work has been done concerning accident-derived long-lived nuclides such as {sup 129}I (T{sub 1/2} = 1.57 × 10{sup 7} year) and {sup 36}Cl (T{sub 1/2} = 3.01 × 10{sup 5} year). {sup 129}I and {sup 131}I are both produced by {sup 235}U fission in nuclear reactors. Being isotopes of iodine, these nuclides are expected to behave similarly in the environment. This makes {sup 129}I useful for retrospective reconstruction of {sup 131}I distribution during the initial stages of the accident. On the other hand, {sup 36}Cl is generated during reactor operation via neutron capture reaction of {sup 35}Cl, an impurity in the coolant or reactor component. Resulting {sup 36}Cl/Cl ratio within the reactor is thus much higher compared to that in environment. Similar to {sup 129}I, {sup 36}Cl is expected to have leaked out during the accident and it is important to evaluate its effects. In this study, {sup 129}I concentrations were determined in several surface soil samples collected around F1NPP. Average {sup 129}I/{sup 131}I ratio was estimated to be 26.1 ± 5.8 as of March 11, 2011, consistent with calculations using ORIGEN2 code and other published data. {sup 36}Cl/Cl ratios in some of the soil samples were likewise measured and ranged from 1.1 × 10{sup −12} to 2.6 × 10{sup −11}. These are higher compared to ratios measured around F1NPP before the accident. A positive correlation between {sup 36}Cl and {sup 129}I concentration was observed.

  18. Measurement of long-lived radionuclides in surface soil around F1NPP accident site by Accelerator Mass Spectrometry

    Science.gov (United States)

    Miyake, Yasuto; Matsuzaki, Hiroyuki; Sasa, Kimikazu; Takahashi, Tsutomu

    2015-10-01

    In March 2011, vast amounts of radionuclides were released into the environment due to the Fukushima Daiichi Nuclear Power Plant (F1NPP) accident. However, very little work has been done concerning accident-derived long-lived nuclides such as 129I (T1/2 = 1.57 × 107 year) and 36Cl (T1/2 = 3.01 × 105 year). 129I and 131I are both produced by 235U fission in nuclear reactors. Being isotopes of iodine, these nuclides are expected to behave similarly in the environment. This makes 129I useful for retrospective reconstruction of 131I distribution during the initial stages of the accident. On the other hand, 36Cl is generated during reactor operation via neutron capture reaction of 35Cl, an impurity in the coolant or reactor component. Resulting 36Cl/Cl ratio within the reactor is thus much higher compared to that in environment. Similar to 129I, 36Cl is expected to have leaked out during the accident and it is important to evaluate its effects. In this study, 129I concentrations were determined in several surface soil samples collected around F1NPP. Average 129I/131I ratio was estimated to be 26.1 ± 5.8 as of March 11, 2011, consistent with calculations using ORIGEN2 code and other published data. 36Cl/Cl ratios in some of the soil samples were likewise measured and ranged from 1.1 × 10-12 to 2.6 × 10-11. These are higher compared to ratios measured around F1NPP before the accident. A positive correlation between 36Cl and 129I concentration was observed.

  19. Measurement of water-soluble B vitamins in infant formula by liquid chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Huang, Min; Winters, Doug; Crowley, Richard; Sullivan, Darryl

    2009-01-01

    A method has been developed for the simultaneous measurement of multiple B vitamins (i.e., B1, B2, B3, B5, and B6) in infant formulas by LC-MSIMS. The vitamins were extracted with acidic solvent, followed by protein precipitation at a pH range of 4.5 to 5.5, and filtered. This simplified procedure eliminates many of the potential sources of laboratory error and facilitates rapid and efficient analysis. As is common in most cases, isotope internal standards were added to account for variations in sample preparation, as well as changes in MS measurement. In this method, isotope-labeled internal standards of B1, B3, B5, and B6 were used. The factors affecting analytical performance were investigated and optimized. In addition, the stability of these vitamins in the extraction solution was investigated. An acidic condition (5 mM HCl) was applied to successfully stabilize B1, which had shown a decrease in signal when other solvents were used. The quantitative extraction and good stability allowed isotope standards to be added to the filtered sample solution, instead of to the extraction solvent. The addition of the isotope to the small portion of the filtered sample solution significantly reduces cost. A comprehensive evaluation of the analysis of the standard reference material and good spike recovery of the vitamins (100 +/- 6%) demonstrates the accuracy of the method. The results for commercially available infant formula samples were also compared with those obtained using the current microbiological method.

  20. Silicon isotope ratio measurements by inductively coupled plasma tandem mass spectrometry for alteration studies of nuclear waste glasses.

    Science.gov (United States)

    Gourgiotis, Alkiviadis; Ducasse, Thomas; Barker, Evelyne; Jollivet, Patrick; Gin, Stéphane; Bassot, Sylvain; Cazala, Charlotte

    2017-02-15

    High-level, long-lived nuclear waste arising from spent fuel reprocessing is vitrified in silicate glasses for final disposal in deep geologic formations. In order to better understand the mechanisms driving glass dissolution, glass alteration studies, based on silicon isotope ratio monitoring of 29 Si-doped aqueous solutions, were carried out in laboratories. This work explores the capabilities of the new type of quadrupole-based ICP-MS, the Agilent 8800 tandem quadrupole ICP-MS/MS, for accurate silicon isotope ratio determination for alteration studies of nuclear waste glasses. In order to avoid silicon polyatomic interferences, a new analytical method was developed using O 2 as the reaction gas in the Octopole Reaction System (ORS), and silicon isotopes were measured in mass-shift mode. A careful analysis of the potential polyatomic interferences on SiO + and SiO 2 + ion species was performed, and we found that SiO + ion species suffer from important polyatomic interferences coming from the matrix of sample and standard solutions (0.5M HNO 3 ). For SiO 2 + , no interferences were detected, and thus, these ion species were chosen for silicon isotope ratio determination. A number of key settings for accurate isotope ratio analysis like, detector dead time, integration time, number of sweeps, wait time offset, memory blank and instrumental mass fractionation, were considered and optimized. Particular attention was paid to the optimization of abundance sensitivity of the quadrupole mass filter before the ORS. We showed that poor abundance sensitivity leads to a significant shift of the data away from the Exponential Mass Fractionation Law (EMFL) due to the spectral overlaps of silicon isotopes combined with different oxygen isotopes (i.e. 28 Si 16 O 18 O + , 30 Si 16 O 16 O + ). The developed method was validated by measuring a series of reference solutions with different 29 Si enrichment. Isotope ratio trueness, uncertainty and repeatability were found to be

  1. Silicon isotope ratio measurements by inductively coupled plasma tandem mass spectrometry for alteration studies of nuclear waste glasses

    Energy Technology Data Exchange (ETDEWEB)

    Gourgiotis, Alkiviadis, E-mail: alkiviadis.gourgiotis@irsn.fr [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PRP-DGE/SRTG/LT2S, Fontenay-aux-Roses (France); Ducasse, Thomas [CEA, DEN, DTCD, SECM, F-30207 Bagnols-sur-Cèze (France); Barker, Evelyne [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PRP-DGE/SRTG/LT2S, Fontenay-aux-Roses (France); Jollivet, Patrick; Gin, Stéphane [CEA, DEN, DTCD, SECM, F-30207 Bagnols-sur-Cèze (France); Bassot, Sylvain; Cazala, Charlotte [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PRP-DGE/SRTG/LT2S, Fontenay-aux-Roses (France)

    2017-02-15

    High-level, long-lived nuclear waste arising from spent fuel reprocessing is vitrified in silicate glasses for final disposal in deep geologic formations. In order to better understand the mechanisms driving glass dissolution, glass alteration studies, based on silicon isotope ratio monitoring of {sup 29}Si-doped aqueous solutions, were carried out in laboratories. This work explores the capabilities of the new type of quadrupole-based ICP-MS, the Agilent 8800 tandem quadrupole ICP-MS/MS, for accurate silicon isotope ratio determination for alteration studies of nuclear waste glasses. In order to avoid silicon polyatomic interferences, a new analytical method was developed using O{sub 2} as the reaction gas in the Octopole Reaction System (ORS), and silicon isotopes were measured in mass-shift mode. A careful analysis of the potential polyatomic interferences on SiO{sup +} and SiO{sub 2}{sup +} ion species was performed, and we found that SiO{sup +} ion species suffer from important polyatomic interferences coming from the matrix of sample and standard solutions (0.5M HNO{sub 3}). For SiO{sub 2}{sup +}, no interferences were detected, and thus, these ion species were chosen for silicon isotope ratio determination. A number of key settings for accurate isotope ratio analysis like, detector dead time, integration time, number of sweeps, wait time offset, memory blank and instrumental mass fractionation, were considered and optimized. Particular attention was paid to the optimization of abundance sensitivity of the quadrupole mass filter before the ORS. We showed that poor abundance sensitivity leads to a significant shift of the data away from the Exponential Mass Fractionation Law (EMFL) due to the spectral overlaps of silicon isotopes combined with different oxygen isotopes (i.e. {sup 28}Si{sup 16}O{sup 18}O{sup +}, {sup 30}Si{sup 16}O{sup 16}O{sup +}). The developed method was validated by measuring a series of reference solutions with different {sup 29}Si

  2. Otolith oxygen isotopes measured by high-precision secondary ion mass spectrometry reflect life history of a yellowfin sole (Limanda aspera).

    Science.gov (United States)

    Matta, Mary Elizabeth; Orland, Ian J; Ushikubo, Takayuki; Helser, Thomas E; Black, Bryan A; Valley, John W

    2013-03-30

    The oxygen isotope ratio (δ(18)O value) of aragonite fish otoliths is dependent on the temperature and the δ(18)O value of the ambient water and can thus reflect the environmental history of a fish. Secondary ion mass spectrometry (SIMS) offers a spatial-resolution advantage over conventional acid-digestion techniques for stable isotope analysis of otoliths, especially given their compact nature. High-precision otolith δ(18)O analysis was conducted with an IMS-1280 ion microprobe to investigate the life history of a yellowfin sole (Limanda aspera), a Bering Sea species known to migrate ontogenetically. The otolith was cut transversely through its core and one half was roasted to eliminate organic contaminants. Values of δ(18)O were measured in 10-µm spots along three transects (two in the roasted half, one in the unroasted half) from the core toward the edge. Otolith annual growth zones were dated using the dendrochronology technique of crossdating. Measured values of δ(18)O ranged from 29.0 to 34.1‰ (relative to Vienna Standard Mean Ocean Water). Ontogenetic migration from shallow to deeper waters was reflected in generally increasing δ(18)O values from age-0 to approximately age-7 and subsequent stabilization after the expected onset of maturity at age-7. Cyclical variations of δ(18)O values within juvenile otolith growth zones, up to 3.9‰ in magnitude, were caused by a combination of seasonal changes in the temperature and the δ(18)O value of the ambient water. The ion microprobe produced a high-precision and high-resolution record of the relative environmental conditions experienced by a yellowfin sole that was consistent with population-level studies of ontogeny. Furthermore, this study represents the first time that crossdating has been used to ensure the dating accuracy of δ(18)O measurements in otoliths. Copyright © 2013 John Wiley & Sons, Ltd.

  3. Liquid chromatography-tandem mass spectrometry method for the measurement of serum mevalonic acid: a novel marker of hydroxymethylglutaryl coenzyme A reductase inhibition by statins.

    Science.gov (United States)

    Waldron, Jenna; Webster, Craig

    2011-05-01

    Mevalonic acid (MVA) is synthesized at an early and rate-limiting step in the biosynthesis of cholesterol by the enzyme hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase, and is a useful measure of statin efficacy or treatment. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the measurement of serum MVA has been developed. Following the in vitro conversion of MVA to mevalonic acid lactone (MVAL) in the serum, MVAL and a deuterated internal standard were extracted using an online solid-phase extraction procedure. Chromatographic separation was achieved using a Luna PFP column (Phenomenex), with enhanced selectivity and improved resolution for polar compounds. A gradient system was used, with mobile phase comprising methanol and water (5 mmol/L ammonium formate buffer, pH 2.5). Analysis was performed using an API 5000 tandem mass spectrometer (Applied Biosystems) in positive electrospray ionization mode. The method showed excellent recoveries (98 ± 8%) and imprecision (intra-assay coefficient of variation of 2.2% [6.5 ng/mL] and 2.6% [10.5 ng/mL], and inter-assay coefficient of variation of 9% [10.5 ng/mL]). The assay provides a calibration range up to 50 ng/mL with a limit of detection at 0.1 ng/mL. A simple, rapid and analytically specific method has been developed for the measurement of serum MVA, in the form of MVAL. The high analytical sensitivity of the method allows for accurate quantitation of MVAL in serum samples, both at the endogenous levels found in healthy individuals and in statin-treated patients where normal levels are expected to be greatly reduced through the inhibition of HMG-CoA reductase.

  4. Measurement of planetary surface composition by gamma-ray and neutron spectrometry - Preparatory studies for Mars and for the Moon by numerical simulations

    International Nuclear Information System (INIS)

    Gasnault, O.

    1999-01-01

    Gamma-ray and neutron spectrometry sets up a powerful tool of geological and geochemical characterization of planetary surfaces. This method allows to tackle some critical planet science questions: crustal and mantle compositions; ices; volcanism; alteration processes... Most of the neutrons and gamma photons result from the interactions of galactic cosmic rays with matter. The first chapter introduces the physics of these nuclear interactions in planetary soils and in detectors. Our work aims at optimizing the observations by specifying instrumental performances, and by highlighting relations between soil composition and neutron fluxes. Numerical simulations using the GEANT code from CERN support our analysis. The second chapter estimates the performances of the Germanium gamma-ray spectrometer for MARS SURVEYOR 2001. The result of simulations is compared to calibration measurements; then performances are calculated in flight configuration. The background at Mars is estimated to about 160 c/s. The instrument offers a fine sensitivity to: Fe, Mg, K, Si, Th, Cl and O. It will also be possible to measure U, Ti, H, C, S, Ca and Al. The emission lobes at the surface are calculated too. These measurements shall permit a better understanding of the Martian surface. The last chapter deals with fast neutrons [500 keV; 10 MeV] emitted by the Moon. The strong influence of oxygen is underlined. As observed by LUNAR PROSPECTOR, the integrated flux shows a pronounced dependence with regolith content in iron and titanium, allowing the mapping. The influence of the other chemical elements is quantified. A simple mathematical formula is suggested to estimate the integrated neutron flux according to soil composition. At last, a study of hydrogen effects on fast neutron flux is carried out; we examine the possibilities to quantify its abundance in the soil by this method. (author)

  5. Measurement of isotopic composition of lanthanides in reprocessing process solutions by high-performance liquid chromatography with inductively coupled plasma mass spectrometry (HPLC/ICP-MS)

    International Nuclear Information System (INIS)

    Okano, Masanori; Jitsukata, Shu; Kuno, Takehiko; Yamada, Keiji

    2011-01-01

    Isotopic compositions of fission products in process solutions and wastes in a reprocessing plant are valuable to proceed safety study of the solutions and research/development concerning treatment/disposal of the wastes. The amount of neodymium-148 is a reliable indication to evaluate irradiation history. The isotopic compositions of samarium and gadolinium in high radioactive wastes are referred to as essential data to evaluate environmental impact in geological repositories. However, pretreatment of analysis must be done with complicated chemical separation such as solvent extraction and ion exchange. The actual measurement data of isotopic compositions of lanthanides comparable to the one of actinides in spent fuel reprocessing process has not been obtained enough. Rapid and high sensitive analytical technique based on high-performance liquid chromatography (HPLC) with an inductively coupled plasma mass spectrometry (ICP-MS) has been developed for the measurement of isotopic compositions of lanthanides in spent fuel reprocessing solutions. HPLC/ICP-MS measurement system was customized for a glove-box to be applied to the radioactive solutions. The cation exchange chromatographic columns (Shim-pack IC-C1) and injection valve (20μL) were located inside of the glove-box except the chromatographic pump. The elements of lanthanide group were separated by a gradient program of HPLC with α-hydroxyisobutyric acid. Isotopic compositions of lanthanides in eluate was sequentially analyzed by a quadruple ICP-MS. Optimization of parameter of HPLC and ICP-MS measurement system was examined with standard solutions containing 14 lanthanide elements. The elements of lanthanides were separated by HPLC and detected by ICP-MS within 25 minutes. The detection limits of Nd-146, Sm-147 and Gd-157 were 0.37 μg L -1 , 0.69 μg L -1 and 0.47 μg L -1 , respectively. The analytical precision of the above three isotopes was better than 10% for standard solutions of 100 μg L -1 with

  6. Instruments for radiation measurement in life sciences (4). 7. Application of accelerator mass spectrometry for drug development. Human mass balance studies at discovery stage

    International Nuclear Information System (INIS)

    Miyaoka, Teiji

    2005-01-01

    Following the recent trend of Position Paper issued from European Agency for the Evaluation of Medicinal Products on the non-clinical safety studies to support clinical trials with a single micro dose, human mass balance studies at discovery stages were made with special interest in using AMS (accelerator mass spectrometry) with a small amount of hot (radioisotope-labeled) drug. This method was found to be effective for the purpose of screening in the clinical study for pharmaceutical development. To show an example of the test, 5, 50, 500μg/body of C14-ARA (α1A adrenoreceptor antagonist, 50 nCi or 1.85 kBq/body/dose) were given (cross over) to several persons to be inspected and C14-quantity in the blood plasma or urine was determined with AMS until after 168 hours or so. The results of the present experiment demonstrate that human mass balance study at discovery stages is possible with ultra high sensitive measuring systems such as AMS and PET (positron emission tomography). (S. Ohno)

  7. An evaluation of liquid chromatography/mass spectrometry with atmospheric pressure chemical ionization for the rapid and simultaneous measurement of carbamate pesticides and organophorus pesticides

    International Nuclear Information System (INIS)

    Kim, Byung Joo; So, Hun Young

    2000-01-01

    Liquid chromatography/mass spectrometry with an atmospheric pressure chemical ionization interface (LC/APCI/MS) is evaluated for the simultaneous determination of carbamate pesticides and organophosphorus pesticides in a single chromatographic analysis. APCI mass spectra of those compounds were obtained to study their ionization characteristics. APCI provided abundant ions such as protonated molecules and characteristic fragment ions for carbamate pesticides and organophosphorus pesticides. To evaluate the feasibility of the LC/APCI/MS for a routine quantitative analysis, the linearity and repeatability of LC/APCI/MS were examined by measuring standard solution mixtures of five carbamate pesticides and four organophosphorus pesticides over the range of 1 to 100 μg/mL. The peak areas in chromatograms of characteristic ions for those compounds showed less than 3% of variation from run to tun. The standard calibration curves for the nine pesticides show good linearity in the concentration range. The detection limits of the LC/APCI/MS system for those compounds range from 0.006 to 0.2 ng

  8. Simplified sample preparation in the simultaneous measurement of whole blood antimony, bismuth, manganese, and zinc by inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Haglock-Adler, Carrie J; Strathmann, Frederick G

    2015-02-01

    We developed and validated a simplified sample preparation for the analysis of antimony (Sb), bismuth (Bi), manganese (Mn), and zinc (Zn) in whole blood. This simplification included a reduction in sample volume, removal of a lengthy acidic digestion, and optimization of the internal standard. Measurement of Sb, Bi, Mn and Zn in whole blood was conducted using inductively coupled-plasma mass spectrometry. Method performance characteristics, including intra- and inter-assay imprecision, accuracy, linearity, AMR, sensitivity, carryover, sample stability and assay stability were determined in accordance with clinical laboratory standards. In addition, analytical and clinical recoveries were assessed to investigate comparability between goat blood matrix and pooled patient blood. Established assay performance characteristics included inter- and intra-assay imprecision samples, proficiency testing samples, and comparison to an outside reference laboratory. This method overcomes the laborious acidic heat digestion previously used and replaces it with a simplified sample preparation involving an alkaline dilution. The method requires minimal sample preparation with the dilution of alkaline diluent and is validated to quantify Sb and Bi from 1 to 25 μg/L, Mn from 1 to 80 μg/L, and Zn from 50 to 1500 μg/dL in whole blood. Copyright © 2014 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  9. Distribution of heavy metals in Lumbricus terrestris, Aporrectodea longa and A. rosea measured by atomic absorption and X-ray fluorescence spectrometry

    International Nuclear Information System (INIS)

    Andersen, C.; Laursen, J.

    1982-01-01

    Distribution of Ca, Pb, Cd, Zn, Fe and Mn has been investigated in the earthworm species Lumbricus terrestris, Aporectodea longa and A. rosea by atomic absorption and X-ray fluorescence spectrometry measurements. The material of L. terrestris originated from the garden of the Royal Veterinary and Agricultural University in central Copenhagen. Material of the other two species was sampled in sewage sludge treated plots. It was found that lead and cadmium are accumulated in the gut wall and from here transferred to waste nodules (brown bodies). In L. terrestris more lead was transferred to waste nodules than cadmium. Also large amounts of zinc were accumulated in the gut wall. Analyses of L. terrestris calciferous glands showed that these take part in regulation and excretion of a number of heavy metals. Lead and cadmium content was low in the ventral nerve chord and seminal vesicles. A. longa with poorly developed calciferous glands seems to rely more on waste nodule formation in the ultimate immobilization of lead. (author)

  10. Rapid and precise measurement of serum branched-chain and aromatic amino acids by isotope dilution liquid chromatography tandem mass spectrometry.

    Directory of Open Access Journals (Sweden)

    Ruiyue Yang

    Full Text Available BACKGROUND: Serum branched-chain and aromatic amino acids (BCAAs and AAAs have emerged as predictors for the future development of diabetes and may aid in diabetes risk assessment. However, the current methods for the analysis of such amino acids in biological samples are time consuming. METHODS: An isotope dilution liquid chromatography tandem mass spectrometry (ID-LC/MS/MS method for serum BCAAs and AAAs was developed. The serum was mixed with isotope-labeled BCAA and AAA internal standards and the amino acids were extracted with acetonitrile, followed by analysis using LC/MS/MS. The LC separation was performed on a reversed-phase C18 column, and the MS/MS detection was performed via the positive electronic spray ionization in multiple reaction monitoring mode. RESULTS: Specific analysis of the amino acids was achieved within 2 min. Intra-run and total CVs for the amino acids were less than 2% and 4%, respectively, and the analytical recoveries ranged from 99.6 to 103.6%. CONCLUSION: A rapid and precise method for the measurement of serum BCAAs and AAAs was developed and may serve as a quick tool for screening serum BCAAs and AAAs in studies assessing diabetes risk.

  11. Ultra-high-performance liquid chromatography-tandem mass spectrometry measurement of climbazole deposition from hair care products onto artificial skin and human scalp.

    Science.gov (United States)

    Chen, Guoqiang; Hoptroff, Michael; Fei, Xiaoqing; Su, Ya; Janssen, Hans-Gerd

    2013-11-22

    A sensitive and specific ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed and validated for the measurement of climbazole deposition from hair care products onto artificial skin and human scalp. Deuterated climbazole was used as the internal standard. Atmospheric pressure chemical ionization (APCI) in positive mode was applied for the detection of climbazole. For quantification, multiple reaction monitoring (MRM) transition 293.0>69.0 was monitored for climbazole, and MRM transition 296.0>225.1 for the deuterated climbazole. The linear range ran from 4 to 2000 ng mL(-1). The limit of detection (LOD) and the limit of quantification (LOQ) were 1 ng mL(-1) and 4 ng mL(-1), respectively, which enabled quantification of climbazole on artificial skin and human scalp at ppb level (corresponding to 16 ng cm(-2)). For the sampling of climbazole from human scalp the buffer scrub method using a surfactant-modified phosphate buffered saline (PBS) solution was selected based on a performance comparison of tape stripping, the buffer scrub method and solvent extraction in in vitro studies. Using this method, climbazole deposition in in vitro and in vivo studies was successfully quantified. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. Sensitive measurement of vinorelbine in dog plasma by liquid chromatography-electrospray ionization tandem mass spectrometry utilizing transitions from double-charged precursor ions.

    Science.gov (United States)

    Niwa, Makoto; Kawashiro, Takashi

    2011-04-01

    A sensitive high-performance liquid chromatography/tandem mass spectrometry (LC/MS/MS) method for measuring vinorelbine was developed. A 100 µL aliquot of plasma was spiked with deuterium-labeled internal standard and subjected to solid-phase extraction using an Oasis HLB μ-elution plate. Two microliters of the extracted samples was directly injected into LC/MS/MS. Chromatographic separation was achieved on a Capcell Pak C18 UG column (2 × 75 mm) with a gradient elution of methanol (mobile phase B) against 0.05% formic acid in aqueous 10 mm ammonium formate (mobile phase A). The LC flow rate was set to 0.28 mL/min and the gradient (solvent B concentration) was processed from 40 to 90%. In mass spectrometric detection, observation of the reaction from a double-charged precursor ion [M + 2H](2+) (m/z 390) to product ion m/z 122 provided very high sensitivity. The method was validated with a lower limit of detection of 0.2 ng/mL with 0.1 mL of plasma, and the method was used to determine the plasma pharmacokinetics of vinorelbine in dogs. Copyright © 2010 John Wiley & Sons, Ltd.

  13. Hints of supernova debris deposition on the lunar surface: {sup 60}Fe and {sup 53}Mn measurements by means of accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Fimiani, Leticia; Faestermann, Thomas; Gomez Guzman, Jose Manuel; Hain, Karin; Korschinek, Gunther; Ludwig, Peter [Physik Department, Technische Universitaet Muenchen, Garching (Germany); Herzog, Gregory; Ligon, Bret; Park, Jisun [Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ (United States); Rugel, Georg [Forschungszentrum Dresden Rossendorf, Dresden (Germany)

    2013-07-01

    The enhanced concentration of {sup 60}Fe in a deep ocean ferro-manganese crust about (2.1±0.4) Myr old (Fitoussi et al., PRL 101, 121101 (2008)), suggests that one or more supernova (SN) explosions occurred in the vicinity of the Solar System. That observation was only possible with the ultra sensitive Accelerator Mass Spectrometry (AMS) technique at the Maier-Leibnitz-Laboratorium in Munich, where we are able to measure concentrations of {sup 60}Fe/Fe down to a level of 10{sup -16}. Because of its lacking atmosphere and negligible sedimentation rate, the Lunar surface is an excellent quantitative reservoir for SN debris. We searched for live {sup 60}Fe and {sup 53}Mn in samples from 3 Apollo missions. {sup 53}Mn is, similar as {sup 26}Al and {sup 60}Fe, a tool to trace nucleosynthesis activities. It is formed primarily during the explosive silicon-burning of the inner shells of SNe via {sup 53}Fe which β-decays to {sup 53}Mn with an 8.51 min half-life. Samples where we found an enhanced {sup 60}Fe concentration showed also an enhancement of {sup 53}Mn. If confirmed, this could be the first detection of live {sup 53}Mn originating from nucleosynthesis.

  14. Simultaneous measurement of proline and related compounds in oak leaves by high-performance ligand-exchange chromatography and electrospray ionization mass spectrometry for environmental stress studies.

    Science.gov (United States)

    Oufir, Mouhssin; Schulz, Nadine; Sha Vallikhan, Patan Shaik; Wilhelm, Eva; Burg, Kornel; Hausman, Jean-Francois; Hoffmann, Lucien; Guignard, Cedric

    2009-02-13

    A mass spectrometer was coupled to high-performance ligand-exchange liquid chromatography (HPLEC) for simultaneous analysis of stress associated solutes such as proline, hydroxyproline, methylproline, glycine betaine and trigonelline extracted from leaves of drought stressed oaks and an internal standard namely N-acetylproline. Methanol/chloroform/water extracts were analyzed using an Aminex HPX-87C column and specifically quantified by the positive ion mode of an electrospray ionisation-mass spectrometry (ESI-MS) in single ion monitoring (SIM) mode. The recovery of N-acetyl proline added to oak leaf extracts ranged from 85.2 to 122.1% for an intra-day study. Standard calibration curves showed good linearity in the measured range from 0.3125 to 10micromolL(-1) with the lowest correlation coefficient of 0.99961 for trigonelline. The advantages of this alternative procedure, compared to previously published methods using fluorescence or amperometric detections, are the simultaneous and direct detection of osmoprotectants in a single chromatographic run, a minimal sample preparation, a good specificity and reduced limits of quantification, ranging from 0.1 to 0.6micromolL(-1). Fifty-six days of water deficit exposure resulted in increased foliar free proline levels (2.4-fold, P<0.001, 155micromolg(-1) FW) and glycine betaine contents (2.5-fold, P<0.05, 175micromolg(-1) FW) of drought stressed oak compared to control.

  15. Radioactivity measurements in soils surrounding four coal-fired power plants in Serbia by gamma-ray spectrometry and estimated dose

    Directory of Open Access Journals (Sweden)

    Vukašinović Ivana Ž.

    2014-01-01

    Full Text Available The study of spatial distribution of activity concentration of 238U, 226Ra, 210Pb, 232Th, 40K, and 137Cs radionuclides in the surface soil samples (n = 42 collected in the vicinity of four coal-fired power plants in Serbia is presented. Radioactivity measurements in soils performed by gamma-ray spectrometry showed values [Bqkg-1] in the range: 15-117 for 238U, 21-115 for 226Ra, 33-65 for 210Pb, 20-69 for 232Th, 324-736 for 40K, and 2-59 for 137Cs. Surface soil radio-activity that could have resulted from deposition of radionuclides from airborne discharges or resuspension of ash from disposal sites showed no enhanced levels. It was found that variation of soil textural properties, pH values, and carbonate content influenced activity levels of natural radionuclides while radiocesium activities were associated with soil organic matter content. Modification of some soil properties was observed in the immediate vicinity (<1 km of power plants where the soil was more alkaline with coarser particles (0.2-0.05 mm and carbonates accumulated. Calculated average values of the absorbed gamma dose rate and annual external effective dose originating from the terrestrial radionuclides were 69.4 nGy/h and 0.085 mSv, respectively. [Projekat Ministarstva nauke Republike Srbije, br. 4007: Studying climate change and its influence on the environment: impacts, adaptation and mitigation

  16. Measurement of the 13C/12C ratio of soil-plant individual sugars by gas chromatography/combustion/isotope-ratio mass spectrometry of silylated derivatives.

    Science.gov (United States)

    Derrien, Delphine; Balesdent, Jérôme; Marol, Christine; Santaella, Catherine

    2003-01-01

    Carbohydrate is an important pool in the terrestrial carbon cycle. The potential offered by natural and artificial 13C-labelling techniques should therefore be applied to the investigation of the dynamics of individual sugars in soils. For this reason, we evaluated the method of 13C sugar analysis by gas chromatography/combustion/isotope-ratio mass spectrometry (GC/C/IRMS) after hydrolysis and direct trimethylsilylation. Trimethylsilylation involved the addition of several carbon atoms per sugar. These atoms have to be taken into account in the estimation of the carbon isotope ratio. The analysis of standard and natural pentoses and hexoses of known 13C enrichments revealed that the number of analysed added carbon atoms was less than expected from stoichiometry. This was attributed to incomplete derivatization and/or incomplete oxidation of methylsilyl carbon before IRMS. Using a calibration of the number of analysed added carbon atoms, the isotope excess of enriched samples could be determined with a relative error close to 5%. Concerning the determination of natural abundances by GC/C/IRMS, we could measure the delta 13C of standard C3- and C4-derived sugars with an accuracy of +/-1.5 per thousand using the previous calibration. We were able to apply this technique to plant-soil systems labelled by pulse-chase of 13CO2, revealing the nature and dynamics of sugars in the plant rhizosphere. Copyright 2003 John Wiley & Sons, Ltd.

  17. An evaluation of liquid chromatography/mass spectrometry with atmospheric pressure chemical ionization for the rapid and simultaneous measurement of carbamate pesticides and organophorus pesticides

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Byung Joo; So, Hun Young [Korea Research Institute of Standards and Sceince, Taejon (Korea, Republic of)

    2000-05-01

    Liquid chromatography/mass spectrometry with an atmospheric pressure chemical ionization interface (LC/APCI/MS) is evaluated for the simultaneous determination of carbamate pesticides and organophosphorus pesticides in a single chromatographic analysis. APCI mass spectra of those compounds were obtained to study their ionization characteristics. APCI provided abundant ions such as protonated molecules and characteristic fragment ions for carbamate pesticides and organophosphorus pesticides. To evaluate the feasibility of the LC/APCI/MS for a routine quantitative analysis, the linearity and repeatability of LC/APCI/MS were examined by measuring standard solution mixtures of five carbamate pesticides and four organophosphorus pesticides over the range of 1 to 100 {mu}g/mL. The peak areas in chromatograms of characteristic ions for those compounds showed less than 3% of variation from run to tun. The standard calibration curves for the nine pesticides show good linearity in the concentration range. The detection limits of the LC/APCI/MS system for those compounds range from 0.006 to 0.2 ng.

  18. Selective measurements of isoprene and 2-methyl-3-buten-2-ol based on NO+ ionization mass spectrometry

    Directory of Open Access Journals (Sweden)

    W. Jud

    2012-12-01

    Full Text Available Biogenic VOC emissions are often dominated by 2-methyl-1,3-butadiene (isoprene and 2-methyl-3-buten-2-ol (232 MBO. Here we explore the possibility to selectively distinguish these species using NO+ as a primary ion in a conventional PTR-MS equipped with an SRI unit. High purity of NO+ (>90% as a primary ion was utilized in laboratory and field experiments using a conventional PTR-TOF-MS. Isoprene is ionized via charge transfer leading to the major product ion C5H8+ (>99% (e.g. Spanel and Smith, 1998. 232 MBO undergoes a hydroxide ion transfer reaction resulting in the major product ion channel C5H9+ (>95% (e.g. Amelynck et al., 2005. We show that both compounds are ionized with little fragmentation (>5% under standard operating conditions. Typical sensitivities of 11.1 ± 0.1 (isoprene and 12.9 ± 0.1 (232 MBO ncps ppbv−1 were achieved, which correspond to limit of detections of 18 and 15 pptv respectively for a 10 s integration time. Sensitivities decreased at higher collisional energies. Calibration experiments showed little humidity dependence. We tested the setup at a field site in Colorado dominated by ponderosa pine, a 232 MBO emitting plant species. Our measurements confirm 232 MBO as the dominant biogenic VOC at this site, exhibiting typical average daytime concentrations between 0.2–1.4 ppbv. The method is able to detect the presence of trace levels of isoprene at this field site (90–250 ppt without any interference from 232 MBO, which would not be feasible using H3O+ ionization chemistry, and which currently also remains a challenge for other analytical techniques (e.g. gas chromatographic methods.

  19. Coincidence measurements in α/β/γ spectrometry with phoswich detectors using digital pulse shape discrimination analysis

    International Nuclear Information System (INIS)

    Celis, B. de; Fuente, R. de la; Williart, A.; Celis Alonso, B. de

    2007-01-01

    A novel system has been developed for the detection of low radioactivity levels using coincidence techniques. The device combines a phoswich detector for α/β/γ ray recognition with a fast digital card for electronic pulse analysis. The detector is able to discriminate different types of radiation in a mixed α/β/γ field and can be used in a coincidence mode by identifying the composite signal produced by the simultaneous detection of β particles in a plastic scintillator and γ rays in an NaI(Tl) scintillator. Use of a coincidence technique with phoswich detectors was proposed recently to verify the Nuclear Test Ban Treaty, which made it necessary to monitor the low levels of xenon radioisotopes produced by underground nuclear explosions. Previous studies have shown that combining CaF 2 (Eu) for β ray detection and NaI(Tl) for γ ray detection makes it difficult to identify the coincidence signals because of the similar fluorescence decay times of the two scintillators. With the device proposed here, it is possible to identify the coincidence events owing to the short fluorescence decay time of the plastic scintillator. The sensitivity of the detector may be improved by employing liquid scintillators, which allow low radioactivity levels from actinides to be measured when present in environmental samples. The device developed is simpler to use than conventional coincidence equipment because it uses a single detector and electronic circuit, and it offers fast and precise analysis of the coincidence signals by employing digital pulse shape analysis

  20. Correction for the 17O interference in δ(13C) measurements when analyzing CO2 with stable isotope mass spectrometry

    Science.gov (United States)

    Coplen, Tyler B.; Brand, Willi A.; Assonov, Sergey S.

    2010-01-01

    Measurements of δ(13C) determined on CO2 with an isotope-ratio mass spectrometer (IRMS) must be corrected for the amount of 17O in the CO2. For data consistency, this must be done using identical methods by different laboratories. This report aims at unifying data treatment for CO2 IRMS by proposing (i) a unified set of numerical values, and (ii) a unified correction algorithm, based on a simple, linear approximation formula. Because the oxygen of natural CO2 is derived mostly from the global water pool, it is recommended that a value of 0.528 be employed for the factor λ, which relates differences in 17O and 18O abundances. With the currently accepted N(13C)/N(12C) of 0.011 180(28) in VPDB (Vienna Peedee belemnite) reevaluation of data yields a value of 0.000 393(1) for the oxygen isotope ratio N(17O)/N(16O) of the evolved CO2. The ratio of these quantities, a ratio of isotope ratios, is essential for the 17O abundance correction: [N(17O)/N(16O)]/[N(13C)/N(12C)] = 0.035 16(8). The equation [δ(13C) ≈ 45δVPDB-CO2 + 2 17R/13R (45δVPDB-CO2 – λ46δVPDB-CO2)] closely approximates δ(13C) values with less than 0.010 ‰ deviation for normal oxygen-bearing materials and no more than 0.026 ‰ in extreme cases. Other materials containing oxygen of non-mass-dependent isotope composition require a more specific data treatment. A similar linear approximation is also suggested for δ(18O). The linear approximations are easy to implement in a data spreadsheet, and also help in generating a simplified uncertainty budget.

  1. MEASUREMENT OF PYRETHROID RESIDUES IN ENVIRONMENTAL AND FOOD SAMPLES BY ENHANCED SOLVENT EXTRACTION/SUPERCRITICAL FLUID EXTRACTION COUPLED WITH GAS CHROMATOGRAPHY-TANDEM MASS SPECTROMETRY

    Science.gov (United States)

    The abstract summarizes pyrethorid methods development research. It provides a summary of sample preparation and analytical techniques such as supercritical fluid extraction, enhance solvent extraction, gas chromatography and tandem mass spectrometry.

  2. Simultaneous measurement of thirteen steroid hormones in women with polycystic ovary syndrome and control women using liquid chromatography-tandem mass spectrometry.

    Directory of Open Access Journals (Sweden)

    Candace C Keefe

    Full Text Available BACKGROUND: The measurement of adrenal and ovarian androgens in women with PCOS has been difficult based on poor specificity and sensitivity of assays in the female range. METHODS: Women with PCOS (NIH criteria; n = 52 and control subjects with 25-35 day menstrual cycles, no evidence of hyperandrogenism and matched for BMI (n = 42 underwent morning blood sampling. Liquid chromatography-tandem mass spectrometry (LC-MS/MS was used to simultaneously measure 13 steroids from a single blood sample to measure adrenal and ovarian steroids. Androgen and progesterone results were compared in the same samples using RIA. RESULTS: Testosterone, androstenedione, progesterone and 17OH progesterone levels were higher when measured using RIA compared to LC-MS/MS, although the testosterone RIA demonstrated the best agreement with the LC-MS/MS using a Bland-Altman analysis. Results using LC-MS/MS demonstrated that the concentration of androgens and their precursors were higher in women with PCOS than controls [median (2.5, 97.5th %ile; 1607 (638, 3085 vs. 1143 (511, 4784 ng/dL; p = 0.03]. Women with PCOS had higher testosterone [49 (16, 125 vs. 24 (10, 59 ng/dL], androstenedione [203 (98, 476 vs. 106 (69, 223 ng/dL] and 17OH progesterone levels [80 (17, 176 vs. 44 (17, 142 ng/dL] compared to controls (all P<0.02, but no differences in serum concentrations of the adrenal steroids DHEAS, cortisol, corticosterone and their 11 deoxy precursors. Women with PCOS also had an increase in the product:precursor ratio for 3β-hydroxysteroid dehydrogenase [22% (6, 92 vs. 20% (4, 43; p = 0.009]. CONCLUSION: LC-MS/MS was superior to RIA in measuring androstenedione, progesterone and 17OH progesterone levels, while testosterone measurements were better matched in the two assays. Androgen levels were higher in women with PCOS in the absence of a difference in adrenal-predominant steroids. These data support previous findings that the ovary is an important source

  3. Implementation of gas concentration measurement systems using mass spectrometry in containment thermal-hydraulics test facilities: different approaches for calibration and measurement with steam/air/helium mixtures

    International Nuclear Information System (INIS)

    Auban, O.; Malet, J.; Brun, P.; Brinster, J.; Quillico, J. J.; Studer, E.

    2003-01-01

    Thermal-hydraulic test facilities are used to investigate various containment phenomena such as, for example, mixing and stratification of gases or steam condensation in the presence of noncondensable. Experiments are also required for validation of codes possessing capabilities for modelling such three-dimensional effects. The need for advanced instrumentation allowing to measure gas concentration in such conditions (typically: 100-180 .deg. C; 1-10 bar) and to get sufficiently refined information about spatial distribution of the different gas species has become apparent. This paper deals with the implementation of gas analysis systems using some commercial Quadrupole Mass Spectrometers (QMS) that have been recently added to the basic instrumentation in three thermal-hydraulics test facilities namely MISTRA (CEA, France), TOSQAN (IRSN, France) and PANDA (PSI, Switzerland). In recent years, QMS have increasingly been selected for various applications because of attractive metrological characteristics (sensibility, span of concentration range, response time, stability, etc.), relatively compact size and low cost. Although commercial QMS are sold as 'turnkey' systems, these instruments are delicate to bring into operation. As QMS are not absolute instruments, reliable calibration procedures are required for quantitative measurements. A mass spectrometer can be regarded as an ionisation gauge with subsequent separation system for the different ion species. The calculation of gas concentrations considers the partial pressure of a particular gas species to be proportional to the ion current it generates. Anyway, one must know the QMS sensitivity to the gases of interest and the only practical method is to use calibration gases. Calibration must be carried out using mixtures whose compositions are close to any possible sample compositions and the procedure selected should duplicate as closely as possible the measurement conditions established during the real experiment

  4. Measurement of non-enteric emission fluxes of volatile fatty acids from a California dairy by solid phase micro-extraction with gas chromatography/mass spectrometry

    Science.gov (United States)

    Alanis, Phillip; Sorenson, Mark; Beene, Matt; Krauter, Charles; Shamp, Brian; Hasson, Alam S.

    Dairies are a major source of volatile organic compounds (VOCs) in California's San Joaquin Valley; a region that experiences high ozone levels during summer. Short-chain carboxylic acids, or volatile fatty acids (VFAs), are believed to make up a large fraction of VOC emissions from these facilities, although there are few studies to substantiate this. In this work, a method using a flux chamber coupled to solid phase micro-extraction (SPME) fibers followed by analysis using gas chromatography/mass spectrometry was developed to quantify emissions of six VFAs (acetic acid, propanoic acid, butanoic acid, pentanoic acid, hexanoic acid and 3-methyl butanoic acid) from non-enteric sources. The technique was then used to quantify VFA fluxes from a small dairy located on the campus of California State University Fresno. Both animal feed and animal waste are found to be major sources of VFAs, with acetic acid contributing 70-90% of emissions from the sources tested. Measured total acid fluxes during spring (with an average temperature of 20 °C) were 1.84 ± 0.01, 1.06 ± 0.08, (1.3 ± 0.5) × 10 -2, (1.7 ± 0.2) × 10 -2 and (1.2 ± 0.5) × 10 -2 g m -2 h -1 from silage, total mixed rations, flushing lane, open lot and lagoon sources, respectively. VFA emissions from the sources tested total 390 ± 80 g h -1. The data indicate high fluxes of VFAs from dairy facilities, but differences in the design and operation of dairies in the San Joaquin Valley as well as seasonal variations mean that additional measurements must be made to accurately determine emissions inventories for the region.

  5. A simple automated solid-phase extraction procedure for measurement of 25-hydroxyvitamin D3 and D2 by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Knox, Susan; Harris, John; Calton, Lisa; Wallace, A Michael

    2009-05-01

    Measurement of 25-hydroxyvitamin D(3) (25OHD(3)) and D(2) (25OHD(2)) is challenging. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods have been described but they are often complex and difficult to automate. We have developed a simplified procedure involving an automated solid-phase extraction (SPE). Internal standard (hexadeuterated 25-hydroxyvitamin D(3)) was added to serum or plasma followed by protein precipitation with methanol. Following centrifugation, a robotic instrument (CTC PAL [Presearch] for ITSP SPE [MicroLiter Analytical Supplies, Inc]) performed a six-step SPE procedure and the purified samples were injected into the LC-MS/MS. Quantification of 25OHD(3) and 25OHD(2) was by electrospray ionization MS/MS in the multiple-reaction monitoring mode. The lower limit of quantitation was 4.0 nmol/L for 25OHD(3) and 7.5 nmol/L for 25OHD(2). Within- and between-assay precision was below 10% over the concentration range of 22.5-120 nmol/L for D(3) and 17.5-70 nmol/L for D(2) (n = 10). The calibration was linear up to 2500 nmol/L (r = 0.99). Recoveries ranged between 89% and 104% for both metabolites and no ion suppression was observed. The results obtained compared well (r = 0.96) with the IDS-OCTEIA 25-hydroxyvitamin D enzyme immunoassay for samples containing less than 125 nmol/L, at higher concentrations the immunodiagnostic system (IDS) method showed positive bias. Our simplified sample preparation and automated SPE method is suitable for the measurement of 25OHD(3) and D(2) in a routine laboratory environment. The system can process up to 300 samples per day with no cumbersome solvent evaporation step and minimal operator intervention.

  6. Measurement of tissue azithromycin levels in self-collected vaginal swabs post treatment using liquid chromatography and tandem mass spectrometry (LC-MS/MS.

    Directory of Open Access Journals (Sweden)

    Lenka A Vodstrcil

    Full Text Available Azithromycin is recommended for the treatment of uncomplicated urogenital chlamydia infection although the standard 1gram dose sometimes fails to eradicate the infection (treatment failure. One hypothesis proposed for treatment failure has been insufficient levels of the antibiotic at the site of infection. We developed an assay using liquid chromatography and tandem mass spectrometry (LC-MS/MS to measure azithromycin concentration in high-vaginal swabs and monitor how concentration changes over time following routine azithromycin treatment.Azithromycin concentrations were measured in two groups of women either within the first 24h of taking a 1g dose (N = 11 or over 9 days (N = 10. Azithromycin concentrations were normalised to an internal standard (leucine enkephalin, and the bulk lipid species phosphatidylcholine [PC(34:1], using an Agilent 6490 triple quadrupole instrument in positive ionisation mode. The abundances of azithromycin, PC(34:1, and leu-enkephalin were determined by multiple reaction monitoring and absolute levels of azithromycin estimated using standard curves prepared on vaginal specimens.Vaginal azithromycin concentrations of women were rapidly obtained after 5h post-treatment (mean concentration = 1031mcg/mg of lipid, range = 173-2693mcg/mg. In women followed for 9 days, peak concentrations were highest after day 2 (mean concentration = 2206mcg/mg, range = 721-5791mcg/mg, and remained high for at least 9 days with a mean concentration of 384mcg/mg (range = 139-1024mcg/mg on day 9.Our study confirmed that a single 1g dose of azithromycin is rapidly absorbed and remains in the vagina at relatively high levels for at least a week, suggesting that poor antibiotic absorption is unlikely to be an explanation for treatment failure.

  7. Non-linear signal response functions and their effects on the statistical and noise cancellation properties of isotope ratio measurements by multi-collector plasma mass spectrometry

    International Nuclear Information System (INIS)

    Doherty, W.

    2013-01-01

    A nebulizer-centric response function model of the analytical inductively coupled argon plasma ion source was used to investigate the statistical frequency distributions and noise reduction factors of simultaneously measured flicker noise limited isotope ion signals and their ratios. The response function model was extended by assuming i) a single gaussian distributed random noise source (nebulizer gas pressure fluctuations) and ii) the isotope ion signal response is a parabolic function of the nebulizer gas pressure. Model calculations of ion signal and signal ratio histograms were obtained by applying the statistical method of translation to the non-linear response function model of the plasma. Histograms of Ni, Cu, Pr, Tl and Pb isotope ion signals measured using a multi-collector plasma mass spectrometer were, without exception, negative skew. Histograms of the corresponding isotope ratios of Ni, Cu, Tl and Pb were either positive or negative skew. There was a complete agreement between the measured and model calculated histogram skew properties. The nebulizer-centric response function model was also used to investigate the effect of non-linear response functions on the effectiveness of noise cancellation by signal division. An alternative noise correction procedure suitable for parabolic signal response functions was derived and applied to measurements of isotope ratios of Cu, Ni, Pb and Tl. The largest noise reduction factors were always obtained when the non-linearity of the response functions was taken into account by the isotope ratio calculation. Possible applications of the nebulizer-centric response function model to other types of analytical instrumentation, large amplitude signal noise sources (e.g., lasers, pumped nebulizers) and analytical error in isotope ratio measurements by multi-collector plasma mass spectrometry are discussed. - Highlights: ► Isotope ion signal noise is modelled as a parabolic transform of a gaussian variable. ► Flicker

  8. Peroxyacetyl nitrate (PAN and peroxyacetic acid (PAA measurements by iodide chemical ionisation mass spectrometry: first analysis of results in the boreal forest and implications for the measurement of PAN fluxes

    Directory of Open Access Journals (Sweden)

    G. J. Phillips

    2013-02-01

    Full Text Available We describe measurements of peroxyacetyl nitrate (CH3C(OO2NO2, PAN and peroxyacetic acid (CH3C(OOOH, PAA in the Boreal forest using iodide chemical ionization mass spectrometry (ICIMS. The measurements were made during the Hyytiälä United Measurement of Photochemistry and Particles – Comprehensive Organic Particle and Environmental Chemistry (HUMPPA-COPEC-2010 measurement intensive. Mixing ratios of PAN and PAA were determined by measuring the acetate ion signal (CH3C(OO, m/z = 59 resulting from reaction of CH3C(OO2 (from the thermal dissociation of PAN or CH3C(OOOH with iodide ions using alternatively heated and ambient temperature inlet lines. During some periods of high temperature (~ 30 °C and low NOx (< 1 ppbv, PAA mixing ratios were similar to, or exceeded those of PAN and thus contributed a significant fraction of the total acetate signal. PAA is thus a potential interference for ICIMS measurements of PAN, and especially eddy covariance flux measurements in environments where the PAA flux is likely to be a significant proportion of the (short timescale acetate ion variability. Within the range of mixing ratios of NOx measured during HUMPPA-COPEC, the modelled ratio of PAA-to-PAN was found to be sensitive to temperature (through the thermal decomposition rate of PAN and the HO2 mixing ratio, thus providing some constraint to estimates of photochemical activity and oxidation rates in the Boreal environment.

  9. Gamma and X 93 spectrometry

    International Nuclear Information System (INIS)

    1994-05-01

    The Meetings of Gamma and X 93 Spectrometry were held on 12-14 October 1993. The symposium was organized into six sessions: Instrumentation development, Nuclear matter measurement, Method and calibration, Medical applications, Environment survey (radioactive traces measurement), other applications (spent fuels analysis, various techniques). Separate abstracts were prepared for all the papers in this volume. (TEC)

  10. Probing the Composition, Assembly and Activity of Protein Molecular Machines using Native Mass Spectrometry

    NARCIS (Netherlands)

    van de Waterbeemd, M.J.

    2017-01-01

    Native mass spectrometry and mass spectrometry in general, are powerful analytical tools for studying proteins and protein complexes. Native mass spectrometry may provide accurate mass measurements of large macromolecular assemblies enabling the investigation of their composition and stoichiometry.

  11. Development and validation of an ultra-high performance liquid chromatography-tandem mass spectrometry method to measure creatinine in human urine.

    Science.gov (United States)

    Fraselle, S; De Cremer, K; Coucke, W; Glorieux, G; Vanmassenhove, J; Schepers, E; Neirynck, N; Van Overmeire, I; Van Loco, J; Van Biesen, W; Vanholder, R

    2015-04-15

    Despite decades of creatinine measurement in biological fluids using a large variety of analytical methods, an accurate determination of this compound remains challenging. Especially with the novel trend to assess biomarkers on large sample sets preserved in biobanks, a simple and fast method that could cope with both a high sample throughput and a low volume of sample is still of interest. In answer to these challenges, a fast and accurate ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed to measure creatinine in small volumes of human urine. In this method, urine samples are simply diluted with a basic mobile phase and injected directly under positive electrospray ionization (ESI) conditions, without further purification steps. The combination of an important diluting factor (10(4) times) due to the use of a very sensitive triple quadrupole mass spectrometer (XEVO TQ) and the addition of creatinine-d3 as internal standard completely eliminates matrix effects coming from the urine. The method was validated in-house in 2012 according to the EMA guideline on bioanalytical method validation using Certified Reference samples from the German External Quality Assessment Scheme (G-Equas) proficiency test. All obtained results for accuracy and recovery are within the authorized tolerance ranges defined by G-Equas. The method is linear between 0 and 5 g/L, with LOD and LOQ of 5 × 10(-3) g/L and 10(-2) g/L, respectively. The repeatability (CV(r) = 1.03-2.07%) and intra-laboratory reproducibility (CV(RW) = 1.97-2.40%) satisfy the EMA 2012 guideline. The validated method was firstly applied to perform the German G-Equas proficiency test rounds 51 and 53, in 2013 and 2014, respectively. The obtained results were again all within the accepted tolerance ranges and very close to the reference values defined by the organizers of the proficiency test scheme, demonstrating an excellent accuracy of the developed method. The

  12. Correlation between Serum Levels of 3,3',5'-Triiodothyronine and Thyroid Hormones Measured by Liquid Chromatography-Tandem Mass Spectrometry and Immunoassay.

    Science.gov (United States)

    Sakai, Hiroyuki; Nagao, Hidenori; Sakurai, Mamoru; Okumura, Takako; Nagai, Yoshiyuki; Shikuma, Junpei; Ito, Rokuro; Imazu, Tetsuya; Miwa, Takashi; Odawara, Masato

    2015-01-01

    For measuring serum 3,3',5'-triiodothyronine (rT3) levels, radioimmunoassay (RIA) has traditionally been used owing to the lack of other reliable methods; however, it has recently become difficult to perform. Meanwhile, liquid chromatography-tandem mass spectrometry (LC-MS/MS) has recently been attracting attention as a novel alternative method in clinical chemistry. To the best of our knowledge, there are no studies to date comparing results of the quantification of human serum rT3 between LC-MS/MS and RIA. We therefore examined the feasibility of LC-MS/MS as a novel alternative method for measuring serum rT3, thyroxine (T4), and 3,5,3'-triiodothyronine (T3) levels. Assay validation was performed by LC-MS/MS using quality control samples of rT3, T4, and T3 at 4 various concentrations which were prepared from reference compounds. Serum samples of 50 outpatients in our department were quantified both by LC-MS/MS and conventional immunoassay for rT3, T4, and T3. Correlation coefficients between the 2 measurement methods were statistically analyzed respectively. Matrix effects were not observed with our method. Intra-day and inter-day precisions were less than 10.8% and 9.6% for each analyte at each quality control level, respectively. Intra-day and inter-day accuracies were between 96.2% and 110%, and between 98.3% and 108.6%, respectively. The lower limit of quantification was 0.05 ng/mL. Strong correlations were observed between the 2 measurement methods (correlation coefficient, T4: 0.976, p < 0.001; T3: 0.912, p < 0.001; rT3: 0.928, p < 0.001). Our LC-MS/MS system requires no manual cleanup operation, and the process after application of a sample is fully automated; furthermore, it was found to be highly sensitive, and superior in both precision and accuracy. The correlation between the 2 methods over a wide range of concentrations was strong. LC-MS/MS is therefore expected to become a useful tool for clinical diagnosis and research.

  13. Correlation between Serum Levels of 3,3',5'-Triiodothyronine and Thyroid Hormones Measured by Liquid Chromatography-Tandem Mass Spectrometry and Immunoassay.

    Directory of Open Access Journals (Sweden)

    Hiroyuki Sakai

    Full Text Available For measuring serum 3,3',5'-triiodothyronine (rT3 levels, radioimmunoassay (RIA has traditionally been used owing to the lack of other reliable methods; however, it has recently become difficult to perform. Meanwhile, liquid chromatography-tandem mass spectrometry (LC-MS/MS has recently been attracting attention as a novel alternative method in clinical chemistry. To the best of our knowledge, there are no studies to date comparing results of the quantification of human serum rT3 between LC-MS/MS and RIA. We therefore examined the feasibility of LC-MS/MS as a novel alternative method for measuring serum rT3, thyroxine (T4, and 3,5,3'-triiodothyronine (T3 levels.Assay validation was performed by LC-MS/MS using quality control samples of rT3, T4, and T3 at 4 various concentrations which were prepared from reference compounds. Serum samples of 50 outpatients in our department were quantified both by LC-MS/MS and conventional immunoassay for rT3, T4, and T3. Correlation coefficients between the 2 measurement methods were statistically analyzed respectively.Matrix effects were not observed with our method. Intra-day and inter-day precisions were less than 10.8% and 9.6% for each analyte at each quality control level, respectively. Intra-day and inter-day accuracies were between 96.2% and 110%, and between 98.3% and 108.6%, respectively. The lower limit of quantification was 0.05 ng/mL. Strong correlations were observed between the 2 measurement methods (correlation coefficient, T4: 0.976, p < 0.001; T3: 0.912, p < 0.001; rT3: 0.928, p < 0.001.Our LC-MS/MS system requires no manual cleanup operation, and the process after application of a sample is fully automated; furthermore, it was found to be highly sensitive, and superior in both precision and accuracy. The correlation between the 2 methods over a wide range of concentrations was strong. LC-MS/MS is therefore expected to become a useful tool for clinical diagnosis and research.

  14. Measuring the hydrogen/deuterium exchange of proteins at high spatial resolution by mass spectrometry: overcoming gas-phase hydrogen/deuterium scrambling.

    Science.gov (United States)

    Rand, Kasper D; Zehl, Martin; Jørgensen, Thomas J D

    2014-10-21

    Proteins are dynamic molecules that exhibit conformational flexibility to function properly. Well-known examples of this are allosteric regulation of protein activity and ligand-induced conformational changes in protein receptors. Detailed knowledge of the conformational properties of proteins is therefore pertinent to both basic and applied research, including drug development, since the majority of drugs target protein receptors and a growing number of drugs introduced to the market are therapeutic peptides or proteins. X-ray crystallography provides a static picture at atomic resolution of the lowest-energy structure of the native ensemble. There is a growing need for sensitive analytical tools to explore all of the significant molecular structures in the conformational landscape of proteins. Hydrogen/deuterium exchange monitored by mass spectrometry (HDX-MS) has recently emerged as a powerful method for characterizing protein conformational dynamics. The basis of this method is the fact that backbone amides in stable hydrogen-bonded structures (e.g., α-helices and β-sheets) are protected against exchange with the aqueous solvent. All protein structures are dynamic, however, and eventually all of the protecting hydrogen bonds will transiently break as the protein--according to thermodynamic principles--cycles through partially unfolded states that correspond to excited free energy levels. As a result, all of the backbone amides will eventually become temporarily solvent-exposed and exchange-competent over time. Consequently, a folded protein in D2O will gradually incorporate deuterium into its backbone amides, and the kinetics of the process can be readily monitored by mass spectrometry. The deuterium uptake kinetics for the intact protein (global exchange kinetics) represents the sum of the exchange kinetics for the individual backbone amides. Local exchange kinetics is typically achieved by using pepsin digestion under quench conditions (i.e., under cold

  15. A novel ion-exclusion chromatography-mass spectrometry method to measure concentrations and cycling rates of carbohydrates and amino sugars in freshwaters.

    Science.gov (United States)

    Horňák, Karel; Pernthaler, Jakob

    2014-10-24

    The concentrations of free neutral carbohydrates and amino sugars were determined in freshwater samples of distinct matrix complexity, including meso-, eu- and dystrophic lakes and ponds, using high-performance ion-exclusion chromatography (HPIEC) coupled to mass spectrometry (MS). In contrast to other methods, our approach allowed the quantification of free neutral carbohydrates and amino sugars at low nM concentrations without derivatization, de-salting or pre-concentration. New sample preparation procedures were applied prior to injection employing syringe and hollow fiber filtration. Analytes were separated on a strong cation exchange resin under 100% aqueous conditions using 0.1% formic acid as a mobile phase. To minimize background noise in MS, analytes were detected in a multiple reaction monitoring scan mode with double ion filtering. Detection limits of carbohydrates and amino sugars ranged between 0.2 and 2nM at a signal-to-noise ratio >5. Error ranged between 1 and 12% at 0.5-500nM levels. Using a stable isotope dilution approach, both the utilization and recycling of glucose in Lake Zurich was observed. In contrast, N-acetyl-glucosamine was equally rapidly consumed but there was no visible de novo production. The simple and rapid sample preparation makes our protocol suitable for routine analyses of organic compounds in freshwater samples. Application of stable isotope tracers along with accurate measures of carbohydrate and amino sugar concentrations enables novel insights into the compound in situ dynamics. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. A liquid chromatography – tandem mass spectrometry method to measure a selected panel of uremic retention solutes derived from endogenous and colonic microbial metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Loor, Henriette de; Poesen, Ruben [KU Leuven – University of Leuven, Department of Microbiology and Immunology, Laboratory of Nephrology, B-3000 Leuven (Belgium); De Leger, Wout; Dehaen, Wim [KU Leuven – University of Leuven, Department of Chemistry, Division of Molecular Design and Synthesis, B-3000 Leuven (Belgium); Augustijns, Patrick [KU Leuven – University of Leuven, Department of Pharmaceutical and Pharmacological Sciences, Drug Delivery and Disposition, B-3000 Leuven (Belgium); Evenepoel, Pieter [KU Leuven – University of Leuven, Department of Microbiology and Immunology, Laboratory of Nephrology, B-3000 Leuven (Belgium); University Hospitals Leuven, Department of Nephrology and Renal Transplantation, B-3000 Leuven (Belgium); Meijers, Björn, E-mail: bjorn.meijers@uzleuven.be [KU Leuven – University of Leuven, Department of Microbiology and Immunology, Laboratory of Nephrology, B-3000 Leuven (Belgium); University Hospitals Leuven, Department of Nephrology and Renal Transplantation, B-3000 Leuven (Belgium)

    2016-09-14

    Chronic kidney disease (CKD) is associated with an increased risk of mortality and cardiovascular disease, which is, at least partly, mediated by the accumulation of so-called uremic retention solutes. Although there has been an increasing interest in the behavior of these solutes, derived from both the endogenous and colonic microbial metabolism, methods to simultaneously and accurately measure a broad panel of relevant uremic retention solutes remain scarce. We developed a highly sensitive ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method. A high throughput sample preparation was used with extraction of analytes from 50 μl serum using Ostro plate technology. For most solutes, stable isotopes labelled metabolites were used as internal standards. Chromatography was achieved using an Acquity UPLC CSH Fluoro Phenyl column. The total run time was 8 min, the mobile phase was a gradient of 0.1% formic acid in Milli-Q water and pure methanol at a flow rate of 0.5 ml min{sup −1}. Detection was performed using a tandem mass spectrometer with alternated positive and negative electrospray ionization. Calibration curves were linear for all solutes. Precision was assessed according to the NCCLS EP5-T guideline, being below 15% for all metabolites. Mean recoveries were between 83 and 104% for all metabolites. The validated method was successfully applied in a cohort of 488 patients with CKD. We developed and validated a sensitive and robust UPLC-MS/MS method for quantification of 15 uremic retention solutes derived from endogenous and colonic microbial metabolism. This method allows for studying the behavior and relevance of these solutes in patients with CKD. - Highlights: • Simultaneous quantification of fifteen relevant uremic retention solutes. • Comprehensive validation, highly sensitive and high through-put LC-MSMS method. • Comparison of different blood tubes. • Freeze-thaw stability. • Successful implementation in a

  17. Multivariate analytical figures of merit as a metric for evaluation of quantitative measurements using comprehensive two-dimensional gas chromatography-mass spectrometry.

    Science.gov (United States)

    Eftekhari, Ali; Parastar, Hadi

    2016-09-30

    The present contribution is devoted to develop multivariate analytical figures of merit (AFOMs) as a new metric for evaluation of quantitative measurements using comprehensive two-dimensional gas chromatography-mass spectrometry (GC×GC-MS). In this regard, new definition of sensitivity (SEN) is extended to GC×GC-MS data and then, other multivariate AFOMs including analytical SEN (γ), selectivity (SEL) and limit of detection (LOD) are calculated. Also, two frequently used second- and third-order calibration algorithms of multivariate curve resolution-alternating least squares (MCR-ALS) as representative of multi-set methods and parallel factor analysis (PARAFAC) as representative of multi-way methods are discussed to exploit pure component profiles and to calculate multivariate AFOMs. Different GC×GC-MS data sets with different number of components along with various levels of artifacts are simulated and analyzed. Noise, elution time shifts in both chromatographic dimensions, peak overlap and interferences are considered as the main artifacts in this work. Additionally, a new strategy is developed to estimate the noise level using variance-covariance matrix of residuals which is very important to calculate multivariate AFOMs. Finally, determination of polycyclic aromatic hydrocarbons (PAHs) in aromatic fraction of heavy fuel oil (HFO) analyzed by GC×GC-MS is considered as real case to confirm applicability of the proposed metric in real samples. It should be pointed out that the proposed strategy in this work can be used for other types of comprehensive two-dimensional chromatographic (CTDC) techniques like comprehensive two dimensional liquid chromatography (LC×LC). Copyright © 2016 Elsevier B.V. All rights reserved.

  18. High Precision Seawater Sr/Ca Measurements in the Florida Keys by Inductively Coupled Plasma Atomic Emission Spectrometry: Analytical Method and Implications for Coral Paleothermometry

    Science.gov (United States)

    Khare, A.; Kilbourne, K. H.; Schijf, J.

    2017-12-01

    Standard methods of reconstructing past sea surface temperatures (SSTs) with coral skeletal Sr/Ca ratios assume the seawater Sr/Ca ratio is constant. However, there is little data to support this assumption, in part because analytical techniques capable of determining seawater Sr/Ca with sufficient accuracy and precision are expensive and time consuming. We demonstrate a method to measure seawater Sr/Ca using inductively coupled plasma atomic emission spectrometry where we employ an intensity ratio calibration routine that reduces the self- matrix effects of calcium and cancels out the matrix effects that are common to both calcium and strontium. A seawater standard solution cross-calibrated with multiple instruments is used to correct for long-term instrument drift and any remnant matrix effects. The resulting method produces accurate seawater Sr/Ca determinations rapidly, inexpensively, and with a precision better than 0.2%. This method will make it easier for coral paleoclimatologists to quantify potentially problematic fluctuations in seawater Sr/Ca at their study locations. We apply our method to test for variability in surface seawater Sr/Ca along the Florida Keys Reef Tract. We are collecting winter and summer samples for two years in a grid with eleven nearshore to offshore transects across the reef, as well as continuous samples collected by osmotic pumps at four locations adjacent to our grid. Our initial analysis of the grid samples indicates a trend of decreasing Sr/Ca values offshore potentially due to a decreasing groundwater influence. The values differ by as much as 0.05 mmol/mol which could lead to an error of 1°C in mean SST reconstructions. Future work involves continued sampling in the Florida Keys to test for seasonal and interannual variability in seawater Sr/Ca, as well as collecting data from small reefs in the Virgin Islands to test the stability of seawater Sr/Ca under different geologic, hydrologic and hydrographic environments.

  19. Measurement of formic acid, acetic acid and hydroxyacetaldehyde, hydrogen peroxide, and methyl peroxide in air by chemical ionization mass spectrometry: airborne method development

    Science.gov (United States)

    Treadaway, Victoria; Heikes, Brian G.; McNeill, Ashley S.; Silwal, Indira K. C.; O'Sullivan, Daniel W.

    2018-04-01

    A chemical ionization mass spectrometry (CIMS) method utilizing a reagent gas mixture of O2, CO2, and CH3I in N2 is described and optimized for quantitative gas-phase measurements of hydrogen peroxide (H2O2), methyl peroxide (CH3OOH), formic acid (HCOOH), and the sum of acetic acid (CH3COOH) and hydroxyacetaldehyde (HOCH2CHO; also known as glycolaldehyde). The instrumentation and methodology were designed for airborne in situ field measurements. The CIMS quantification of formic acid, acetic acid, and hydroxyacetaldehyde used I- cluster formation to produce and detect the ion clusters I-(HCOOH), I-(CH3COOH), and I-(HOCH2CHO), respectively. The CIMS also produced and detected I- clusters with hydrogen peroxide and methyl peroxide, I-(H2O2) and I-(CH3OOH), though the sensitivity was lower than with the O2- (CO2) and O2- ion clusters, respectively. For that reason, while the I- peroxide clusters are presented, the focus is on the organic acids. Acetic acid and hydroxyacetaldehyde were found to yield equivalent CIMS responses. They are exact isobaric compounds and indistinguishable in the CIMS used. Consequently, their combined signal is referred to as the acetic acid equivalent sum. Within the resolution of the quadrupole used in the CIMS (1 m/z), ethanol and 1- and 2-propanol were potential isobaric interferences to the measurement of formic acid and the acetic acid equivalent sum, respectively. The CIMS response to ethanol was 3.3 % that of formic acid and the response to either 1- or 2-propanol was 1 % of the acetic acid response; therefore, the alcohols were not considered to be significant interferences to formic acid or the acetic acid equivalent sum. The multi-reagent ion system was successfully deployed during the Front Range Air Pollution and Photochemistry Éxperiment (FRAPPÉ) in 2014. The combination of FRAPPÉ and laboratory calibrations allowed for the post-mission quantification of formic acid and the acetic acid equivalent sum observed during the Deep

  20. Improved sample utilization in thermal ionization mass spectrometry isotope ratio measurements: refined development of porous ion emitters for nuclear forensic applications

    Energy Technology Data Exchange (ETDEWEB)

    Baruzzini, Matthew Louis [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-05-08

    The precise and accurate determination of isotopic composition in nuclear forensic samples is vital for assessing origin, intended use and process history. Thermal ionization mass spectrometry (TIMS) is widely accepted as the gold standard for high performance isotopic measurements and has long served as the workhorse in the isotopic ratio determination of nuclear materials. Nuclear forensic and safeguard specialists have relied heavily on such methods for both routine and atypical e orts. Despite widespread use, TIMS methods for the assay of actinide systems continue to be hindered by poor ionization e ciency, often less than tenths of a percent; the majority of a sample is not measured. This represents a growing challenge in addressing nextgeneration nuclear detection needs by limiting the ability to analyze ultratrace quantities of high priority elements that could potentially provide critical nuclear forensic signatures. Porous ion emitter (PIE) thermal ion sources were developed in response to the growing need for new TIMS ion source strategies for improved ionization e ciency, PIEs have proven to be simple to implement, straightforward approach to boosting ion yield. This work serves to expand the use of PIE techniques for the analysis of trace quantities of plutonium and americium. PIEs exhibited superior plutonium and americium ion yields when compared to direct lament loading and the resin bead technique, one of the most e cient methods for actinide analysis, at similar mass loading levels. Initial attempts at altering PIE composition for the analysis of plutonium proved to enhance sample utilization even further. Preliminary investigations of the instrumental fractionation behavior of plutonium and uranium analyzed via PIE methods were conducted. Data collected during these initial trial indicate that PIEs fractionate in a consistent, reproducible manner; a necessity for high precision isotope ratio measurements. Ultimately, PIEs methods were applied for

  1. The influence of different referencing methods on the accuracy of δ(13) C value measurement of ethanol fuel by gas chromatography/combustion/isotope ratio mass spectrometry.

    Science.gov (United States)

    Neves, Laura A; Rodrigues, Janaína M; Daroda, Romeu J; Silva, Paulo R M; Ferreira, Alexandre A; Aranda, Donato A G; Eberlin, Marcos N; Fasciotti, Maíra

    2015-11-15

    Brazil is the largest producer of sugar cane bioethanol in the world. Isotope ratio mass spectrometry (IRMS) is the technique of choice to certify the origin/raw materials for ethanol production, but the lack of certified reference materials (CRMs) for accurate measurements of δ(13) C values traceable to Vienna Pee Dee Belemnite (VPDB), the international zero point for (13) C/(12) C measurements, certified and compatible with gas chromatography (GC)/IRMS instruments may compromise the accuracy of δ(13) C determinations. We evaluated the influence of methods for the calibration and normalization of raw δ(13) C values of ethanol samples. Samples were analyzed by GC/C/IRMS using two different GC columns. Different substances were used as isotopic standards for the working gas calibration. The δ(13) C values obtained with the three methods of normalization were statistically compared with those obtained with elemental analyzer (EA)/IRMS, since the δ(13) C results obtained using EA are traceable to VPDB via the NBS 22 reference material. It was observed that both the isotopic reference material for CO2 calibration and the GC column have a major effect on the δ(13) C measurements, leading to a bias of almost 2-3 ‰ in the δ(13) C values. All three methods of normalization were equivalent in performance, enabling an improvement in the GC/C/IRMS accuracy, compared with the EA/IRMS reference values for the samples. All the methods of CO2 calibration, chromatography and normalization presented in this work demonstrated several sources of traceability and accuracy loss for the determination of δ(13) C values in ethanol fuel samples by GC/C/IRMS. This work has also shown the importance of using proper CRMs traceable to VPBD that should be compatible and certified using GC/C/IRMS, ideally in a wide range of δ(13) C values. This is important not only for bioethanol fuel samples, but also for many analytes commonly analyzed by IRMS. Copyright © 2015 John Wiley & Sons

  2. Simple and accurate measurement of carbamazepine in surface water by use of porous membrane-protected micro-solid-phase extraction coupled with isotope dilution mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Teo, Hui Ling [Chemical Metrology Division, Applied Sciences Group, Health Sciences Authority, 1 Science Park Road, #01-05/06, The Capricorn, Singapore Science Park II, Singapore 117528 (Singapore); Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543 (Singapore); Wong, Lingkai [Chemical Metrology Division, Applied Sciences Group, Health Sciences Authority, 1 Science Park Road, #01-05/06, The Capricorn, Singapore Science Park II, Singapore 117528 (Singapore); Liu, Qinde, E-mail: liu_qinde@hsa.gov.sg [Chemical Metrology Division, Applied Sciences Group, Health Sciences Authority, 1 Science Park Road, #01-05/06, The Capricorn, Singapore Science Park II, Singapore 117528 (Singapore); Teo, Tang Lin; Lee, Tong Kooi [Chemical Metrology Division, Applied Sciences Group, Health Sciences Authority, 1 Science Park Road, #01-05/06, The Capricorn, Singapore Science Park II, Singapore 117528 (Singapore); Lee, Hian Kee, E-mail: chmleehk@nus.edu.sg [Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543 (Singapore)

    2016-03-17

    To achieve fast and accurate analysis of carbamazepine in surface water, we developed a novel porous membrane-protected micro-solid-phase extraction (μ-SPE) method, followed by liquid chromatography-isotope dilution tandem mass spectrometry (LC-IDMS/MS) analysis. The μ-SPE device (∼0.8 × 1 cm) was fabricated by heat-sealing edges of a polypropylene membrane sheet to devise a bag enclosing the sorbent. The analytes (both carbamazepine and isotope-labelled carbamazepine) were first extracted by μ-SPE device in the sample (10 mL) via agitation, then desorbed in an organic solvent (1 mL) via ultrasonication. Several parameters such as organic solvent for pre-conditioning of μ-SPE device, amount of sorbent, adsorption time, and desorption solvent and time were investigated to optimize the μ-SPE efficiency. The optimized method has limits of detection and quantitation estimated to be 0.5 ng L{sup −1} and 1.6 ng L{sup −1}, respectively. Surface water samples spiked with different amounts of carbamazepine (close to 20, 500, and 1600 ng L{sup −1}, respectively) were analysed for the validation of method precision and accuracy. Good precision was obtained as demonstrated by relative standard deviations of 0.7% for the samples with concentrations of 500 and 1600 ng kg{sup −1}, and 5.8% for the sample with concentration of 20 ng kg{sup −1}. Good accuracy was also demonstrated by the relative recoveries in the range of 96.7%–103.5% for all samples with uncertainties of 1.1%–5.4%. Owing to the same chemical properties of carbamazepine and isotope-labelled carbamazepine, the isotope ratio in the μ-SPE procedure was accurately controlled. The use of μ-SPE coupled with IDMS analysis significantly facilitated the fast and accurate measurement of carbamazepine in surface water. - Highlights: • μ-SPE coupled with IDMS for the measurement of carbamazepine. • The method is the first report of coupling μ-SPE with IDMS. • μ-SPE is fast, time

  3. Development of a method for in situ measurement of denitrification in aquifers using 15N tracer tests and membrane inlet mass spectrometry

    Science.gov (United States)

    Eschenbach, W.; Well, R.; Flessa, H.; Walther, W.; Duijnisveld, W. H. M.

    2009-04-01

    In NO3- contaminated aquifers containing reduced compounds like organic carbon or sulfides, denitrification is an intense process. Its characterization is of interest because NO3- consump-tion improves water quality and N2O production can cause emission of this greenhouse gas to the atmosphere. Spatial distribution of NO3- and N2 produced by denitrification in groundwa-ter (excess N2) reflects the NO3- input as well as cumulative denitrification during aquifer pas-sage. Reaction progress (RP) at a given location, i.e. the relative consumption by denitrifica-tion of the NO3- that had been leached to the aquifers, characterizes the stage of the denitrifi-cation process. RP can be derived from the ratio between accumulated gaseous denitrification products and initial NO3- concentrations. The amount and spatial distribution of reduced com-pounds within denitrifying aquifers is not well known. Recent findings from parallel investi-gations on in situ denitrification and reactive compounds suggests that single-well 15N tracer tests might be suitable to characterize the stock of reduced compounds in aquifers (Konrad 2007). The overall objective of our studies is measure the spatial dynamics of denitrification within two sandy aquifers in northern Germany. This includes measurement of the actually occurring denitrification process. Moreover we want to determine the long-term denitrification potential which is governed by the stock of reactive material. Here we present a new approach for in situ-measurement of denitrification at monitoring wells using a combination of 15N-tracer push-pull experiments with in situ analysis of 15N-labled N2 and N2O using membrane inlet mass spectrometry (MIMS). We will present first results from a laboratory test with aquifer mesocosms using the MIMS method. In this test we supplemented aquifer material of two depths (2 and 7 m below surface) of a drinking water catchment in Northwest Germany with K15NO3 solution. After tracer application we

  4. Mass spectrometry with accelerators.

    Science.gov (United States)

    Litherland, A E; Zhao, X-L; Kieser, W E

    2011-01-01

    As one in a series of articles on Canadian contributions to mass spectrometry, this review begins with an outline of the history of accelerator mass spectrometry (AMS), noting roles played by researchers at three Canadian AMS laboratories. After a description of the unique features of AMS, three examples, (14)C, (10)Be, and (129)I are given to illustrate the methods. The capabilities of mass spectrometry have been extended by the addition of atomic isobar selection, molecular isobar attenuation, further ion acceleration, followed by ion detection and ion identification at essentially zero dark current or ion flux. This has been accomplished by exploiting the techniques and accelerators of atomic and nuclear physics. In 1939, the first principles of AMS were established using a cyclotron. In 1977 the selection of isobars in the ion source was established when it was shown that the (14)N(-) ion was very unstable, or extremely difficult to create, making a tandem electrostatic accelerator highly suitable for assisting the mass spectrometric measurement of the rare long-lived radioactive isotope (14)C in the environment. This observation, together with the large attenuation of the molecular isobars (13)CH(-) and (12)CH 2(-) during tandem acceleration and the observed very low background contamination from the ion source, was found to facilitate the mass spectrometry of (14)C to at least a level of (14)C/C ~ 6 × 10(-16), the equivalent of a radiocarbon age of 60,000 years. Tandem Accelerator Mass Spectrometry, or AMS, has now made possible the accurate radiocarbon dating of milligram-sized carbon samples by ion counting as well as dating and tracing with many other long-lived radioactive isotopes such as (10)Be, (26)Al, (36)Cl, and (129)I. The difficulty of obtaining large anion currents with low electron affinities and the difficulties of isobar separation, especially for the heavier mass ions, has prompted the use of molecular anions and the search for alternative

  5. HI-resolution gamma spectrometry measurements of U-238, TH-232, K-40 and CS-137 concentrations in soil samples from Capao Island at CTEx

    International Nuclear Information System (INIS)

    Oliveira, Luciano S.R.; Oliveira, Celio J.V.; Vilela, Paulo R.T.; Vital, Helio C.

    2013-01-01

    Absolute soil concentrations of U-238, Th-232, K-40 and Cs-137 samples collected from Capao Island have been measured by using Hi-Resolution Gamma HPGe Spectrometry. The area of interest encompasses an embankment in a mangrove swamp in Guaratiba, Rio de Janeiro, where nuclear, chemical and biological defense laboratories of the Brazilian Army Technology Center (CTEx) are located. In order to ensure that no significant environmental impact has resulted from neutron physics experiments performed in a graphite subcritical assembly in addition to the operation of two cesium-driven irradiating facilities, routine monitoring of those isotopes have been regularly performed. A total of eight 250 ml samples of mangrove and embankment soils were extracted from four sites of known coordinates within an area of 300 x 300 m 2 and remained stored for a minimum thirty-day period to allow equilibrium to be reached. Collection and preparation of samples were made according to previously established procedures. High purity germanium detectors were used to obtain high-resolution gamma spectra and counting times were required to exceed 30 hours in order to yield sufficient statistical accuracy. Energy and efficiency calibration curves of the counting system were determined by using the GENIE 2000 software for analysis of the gamma spectrum generated by nine standard sources with a total of 11 peak energies ranging from 0.05 to 1.3 MeV. The results, corrected for background, have been expressed as absolute specific activities. All experiments have been made in the Laboratory for Identification of Radiological Agents (LIAR) at CTEx. No trace of cesium-137 has been found and the measured levels of uranium-238, in the order of 10 Bq/kg, are close to the global mean. However, some data have been found to slightly exceed the expected normal range for thorium-232 (60% of samples) and potassium-40 (20% of samples). Since there is no handling of those isotopes in the site or others that could

  6. HI-resolution gamma spectrometry measurements of U-238, TH-232, K-40 and CS-137 concentrations in soil samples from Capao Island at CTEx

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Luciano S.R.; Oliveira, Celio J.V.; Vilela, Paulo R.T.; Vital, Helio C., E-mail: vital@ctex.eb.br [Centro Tecnologico do Exercito (DDQBN/CTEX), Rio de Janeiro, RJ (Brazil). Div. de Defesa Quimica, Biologica e Nuclear. Secao de Defesa Nuclear

    2013-07-01

    Absolute soil concentrations of U-238, Th-232, K-40 and Cs-137 samples collected from Capao Island have been measured by using Hi-Resolution Gamma HPGe Spectrometry. The area of interest encompasses an embankment in a mangrove swamp in Guaratiba, Rio de Janeiro, where nuclear, chemical and biological defense laboratories of the Brazilian Army Technology Center (CTEx) are located. In order to ensure that no significant environmental impact has resulted from neutron physics experiments performed in a graphite subcritical assembly in addition to the operation of two cesium-driven irradiating facilities, routine monitoring of those isotopes have been regularly performed. A total of eight 250 ml samples of mangrove and embankment soils were extracted from four sites of known coordinates within an area of 300 x 300 m{sup 2} and remained stored for a minimum thirty-day period to allow equilibrium to be reached. Collection and preparation of samples were made according to previously established procedures. High purity germanium detectors were used to obtain high-resolution gamma spectra and counting times were required to exceed 30 hours in order to yield sufficient statistical accuracy. Energy and efficiency calibration curves of the counting system were determined by using the GENIE 2000 software for analysis of the gamma spectrum generated by nine standard sources with a total of 11 peak energies ranging from 0.05 to 1.3 MeV. The results, corrected for background, have been expressed as absolute specific activities. All experiments have been made in the Laboratory for Identification of Radiological Agents (LIAR) at CTEx. No trace of cesium-137 has been found and the measured levels of uranium-238, in the order of 10 Bq/kg, are close to the global mean. However, some data have been found to slightly exceed the expected normal range for thorium-232 (60% of samples) and potassium-40 (20% of samples). Since there is no handling of those isotopes in the site or others that

  7. High-precision measurements of uranium and thorium isotopic ratios by multi-collector inductively coupled plasma mass spectrometry (MC-ICPMS)

    Science.gov (United States)

    Wang, Lisheng; Ma, Zhibang; Duan, Wuhui

    2015-04-01

    Isotopic compositions of U-Th and 230Th dating have been widely used in earth sciences, such as chronology, geochemistry, oceanography and hydrology. In this study, five ages of different carbonate samples were measured using 230Th dating technique with U-Th high-precision isotopic measurements by multi-collector inductively coupled plasma mass spectrometry, in Uranium-series Chronology Laboratory, Institute of Geology and Geophysics, Chinese Academy of Sciences.In this study, the precision and accuracy of uranium isotopic composition were estimated by measuring the uranium ratios of NBS-CRM 112A, NBS-CRM U500 and HU-1. The mean measured ratios, 234U/238U = 52.86 (±0.04) × 10-6 and δ234U = -38.36 (±0.77) × 10-3 for NBS-CRM 112A, 234U/238U = 10.4184 (±0.0001) × 10-3, 236U/238U = 15.43 (±0.01) × 10-4 and 238U/235U = 1.00021 (±0.00002) for NBS-CRM U500, 234U/238U = 54.911 (±0.007) and δ234U = -1.04 (±0.13) × 10-3 for HU-1 (95% confidence levels). The U isotope data for standard reference materials are in excellent agreement with previous studies, further highlighting the reliability and analytical capabilities of our technique. We measured the thorium isotopic ratios of three different thorium standards by MC-ICPMS. The three standards (Th-1, Th-2 and Th-3) were mixed by HU-1 and NBS 232Th standard, with the 230Th/232Th ratios from 10-4 to 10-6. The mean measured atomic ratios, 230Th/232Th = 2.1227 (±0.0024) × 10-6, 2.7246 (±0.0026) × 10-5, and 2.8358 (±0.0007) × 10-4 for Th-1, Th-2 and Th-3 (95% confidence levels), respectively. Using this technique, the following standard samples were dated by MC-ICPMS. Sample RKM-4, collected from Babardos Kendal Hill terrace, was used during the first stage of the Uranium-Series Intercomparison Project (USIP-I). Samples 76001, RKM-5 and RKM-6 were studied during the second stage of the USIP program (USIP-II). Sample 76001 is a laminated flowstone, collected from Sumidero Terejapa, Chiapas, Mexico, and samples

  8. Kinetics of ethanol decay in mouth- and nose-exhaled breath measured on-line by selected ion flow tube mass spectrometry following varying doses of alcohol

    Czech Academy of Sciences Publication Activity Database

    Smith, D.; Pysanenko, Andriy; Španěl, Patrik

    2010-01-01

    Roč. 24, č. 7 (2010), s. 1066-1074 ISSN 0951-4198 R&D Projects: GA ČR GA202/09/0800 Institutional research plan: CEZ:AV0Z40400503 Keywords : mass spectrometry * blood-alcohol * breath Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.846, year: 2010

  9. Application of liquid chromatography-mass spectrometry to measure the concentrations and study the synthesis of short chain fatty acids following stable isotope infusions

    NARCIS (Netherlands)

    Meesters, R.J.W.; Eijk, H.M.H. van; Have, G.A.M. ten; Graaf, A.A. de; Venema, K.; Rossum, B.E.J. van; Deutz, N.E.P.

    2007-01-01

    A new method involving zinc sulphate deproteinization was developed to study short chain fatty acids (SCFA) production in the colon and subsequent occurrence of SCFA in blood. SCFA were baseline separated in a 30 min cycle using ion-exclusion chromatography and detected by mass spectrometry.

  10. Mass spectrometry with particle accelerator

    International Nuclear Information System (INIS)

    Anon.

    1983-01-01

    The heavy ion accelerator use is renewing the ultrasensitive mass spectrometry in extending the detection limits. These new devices allow the measurement of rare isotope ratio, as 10 Be, 14 C, 26 Al, 36 Cl or 41 Ca, from the earth natural reservoirs [fr

  11. Cross validation of gas chromatography-flame photometric detection and gas chromatography-mass spectrometry methods for measuring dialkylphosphate metabolites of organophosphate pesticides in human urine.

    Science.gov (United States)

    Prapamontol, Tippawan; Sutan, Kunrunya; Laoyang, Sompong; Hongsibsong, Surat; Lee, Grace; Yano, Yukiko; Hunter, Ronald Elton; Ryan, P Barry; Barr, Dana Boyd; Panuwet, Parinya

    2014-01-01

    We report two analytical methods for the measurement of dialkylphosphate (DAP) metabolites of organophosphate pesticides in human urine. These methods were independently developed/modified and implemented in two separate laboratories and cross validated. The aim was to develop simple, cost effective, and reliable methods that could use available resources and sample matrices in Thailand and the United States. While several methods already exist, we found that direct application of these methods required modification of sample preparation and chromatographic conditions to render accurate, reliable data. The problems encountered with existing methods were attributable to urinary matrix interferences, and differences in the pH of urine samples and reagents used during the extraction and derivatization processes. Thus, we provide information on key parameters that require attention during method modification and execution that affect the ruggedness of the methods. The methods presented here employ gas chromatography (GC) coupled with either flame photometric detection (FPD) or electron impact ionization-mass spectrometry (EI-MS) with isotopic dilution quantification. The limits of detection were reported from 0.10ng/mL urine to 2.5ng/mL urine (for GC-FPD), while the limits of quantification were reported from 0.25ng/mL urine to 2.5ng/mL urine (for GC-MS), for all six common DAP metabolites (i.e., dimethylphosphate, dimethylthiophosphate, dimethyldithiophosphate, diethylphosphate, diethylthiophosphate, and diethyldithiophosphate). Each method showed a relative recovery range of 94-119% (for GC-FPD) and 92-103% (for GC-MS), and relative standard deviations (RSD) of less than 20%. Cross-validation was performed on the same set of urine samples (n=46) collected from pregnant women residing in the agricultural areas of northern Thailand. The results from split sample analysis from both laboratories agreed well for each metabolite, suggesting that each method can produce

  12. Nature of unresolved complex mixture in size-distributed emissions from residential wood combustion as measured by thermal desorption-gas chromatography-mass spectrometry

    Science.gov (United States)

    Hays, Michael D.; Smith, N. Dean; Dong, Yuanji

    2004-08-01

    Unresolved complex mixture (UCM) is an analytical artifact of gas chromatographs of combustion source-related fine aerosol extracts. In this study the UCM is examined in size-resolved fine aerosol emissions from residential wood combustion. The aerosols are sorted by size in an electrical low-pressure impactor (ELPI) and subsequently analyzed by thermal desorption/gas chromatography/mass spectrometry (TD/GC/MS). A semiquantitative system for predicting the branched alkane, cycloalkane, alkylbenzene, C3-, C4-, C5-alkylbenzene, methylnaphthalene, C3-, C4-, C5-alkylnaphthalene, methylphenanthrene C2-, C3-alkylphenanthrene, and dibenzothiophene concentrations in the UCM is introduced. Analysis by TD/GS/MS detects UCM on each ELPI stage for all six combustion tests. The UCM baseline among the different fuel types is variable. In particular, the UCM of Pseudotsuga sp. is enriched in later-eluting compounds of lower volatility. A high level of reproducibility is achieved in determining UCM areas. UCM fractions (UCM ion area/total extracted ion chromatograph area) by individual ELPI stage return a mean relative standard deviation of 19.1% over the entire combustion test set, indicating a highly consistent UCM fraction across the ELPI size boundaries. Among the molecular ions investigated, branched alkane (m/z 57) and dibenzothiophene (m/z 212 and 226) constituents are most abundant in UCM emissions from RWC, collectively accounting for 64-95% of the targeted chemical species. The total UCM emissions span 446-756 mg/kg of dry biomass burned and correspond to an upper limit of 7.1% of the PM2.5 mass. The UCM emissions are primarily accumulation mode (0.1 μm ≤ aerodynamic diameter (da) ≤ 1 μm), with a geometric mean diameter (dg) range of 120.3-518.4 nm. UCM in PM2.5 is chemically asymmetric (shifted to finer da), typically clustering at da ≤ 1 μm. Measurable shifts in dg and changes in distribution widths (σg) on an intratest basis suggest that the particle density

  13. Mobile membrane introduction tandem mass spectrometry for on-the-fly measurements and adaptive sampling of VOCs around oil and gas projects in Alberta, Canada

    Science.gov (United States)

    Krogh, E.; Gill, C.; Bell, R.; Davey, N.; Martinsen, M.; Thompson, A.; Simpson, I. J.; Blake, D. R.

    2012-12-01

    The release of hydrocarbons into the environment can have significant environmental and economic consequences. The evolution of smaller, more portable mass spectrometers to the field can provide spatially and temporally resolved information for rapid detection, adaptive sampling and decision support. We have deployed a mobile platform membrane introduction mass spectrometer (MIMS) for the in-field simultaneous measurement of volatile and semi-volatile organic compounds. In this work, we report instrument and data handling advances that produce geographically referenced data in real-time and preliminary data where these improvements have been combined with high precision ultra-trace VOCs analysis to adaptively sample air plumes near oil and gas operations in Alberta, Canada. We have modified a commercially available ion-trap mass spectrometer (Griffin ICX 400) with an in-house temperature controlled capillary hollow fibre polydimethylsiloxane (PDMS) polymer membrane interface and in-line permeation tube flow cell for a continuously infused internal standard. The system is powered by 24 VDC for remote operations in a moving vehicle. Software modifications include the ability to run continuous, interlaced tandem mass spectrometry (MS/MS) experiments for multiple contaminants/internal standards. All data are time and location stamped with on-board GPS and meteorological data to facilitate spatial and temporal data mapping. Tandem MS/MS scans were employed to simultaneously monitor ten volatile and semi-volatile analytes, including benzene, toluene, ethylbenzene and xylene (BTEX), reduced sulfur compounds, halogenated organics and naphthalene. Quantification was achieved by calibrating against a continuously infused deuterated internal standard (toluene-d8). Time referenced MS/MS data were correlated with positional data and processed using Labview and Matlab to produce calibrated, geographical Google Earth data-visualizations that enable adaptive sampling protocols

  14. Coincidence gamma-ray spectrometry

    DEFF Research Database (Denmark)

    Markovic, Nikola; Roos, Per; Nielsen, Sven Poul

    2017-01-01

    Gamma-ray spectrometry with high-purity germanium (HPGe) detectors is often the technique of choice in an environmental radioactivity laboratory. When measuring environmental samples associated activities are usually low so an important parameter that describes the performance of the spectrometer...... for a nuclide of interest is the minimum detectable activity (MDA). There are many ways for lowering the MDAs in gamma spectrometry. Recently, developments of fast and compact digital acquisition systems have led to growing number of multiple HPGe detector spectrometers. In these applications all detected...

  15. A compact fast data acquisition and data analysis system for time of flight mass spectrometry. Time and S.I. intensity measurements with a new multistop TDC

    International Nuclear Information System (INIS)

    Della-Negra, S.; Le Beyec, Y.

    1987-01-01

    A data acquisition and processing system for time of flight mass spectrometry, based on a PC-AT computer with an additional memory card was developed, and analysis software was written. About 100,000 counts/sec can be analyzed and stored in the memory. In the coincidence mode, 1000 start events with 10 stop events (per sec) on one time digital converter allow 10 spectra to be recorded. Examples of printouts are shown

  16. Rapid and Precise Measurement of Serum Branched-Chain and Aromatic Amino Acids by Isotope Dilution Liquid Chromatography Tandem Mass Spectrometry

    OpenAIRE

    Yang, Ruiyue; Dong, Jun; Guo, Hanbang; Li, Hongxia; Wang, Shu; Zhao, Haijian; Zhou, Weiyan; Yu, Songlin; Wang, Mo; Chen, Wenxiang

    2013-01-01

    BACKGROUND: Serum branched-chain and aromatic amino acids (BCAAs and AAAs) have emerged as predictors for the future development of diabetes and may aid in diabetes risk assessment. However, the current methods for the analysis of such amino acids in biological samples are time consuming. METHODS: An isotope dilution liquid chromatography tandem mass spectrometry (ID-LC/MS/MS) method for serum BCAAs and AAAs was developed. The serum was mixed with isotope-labeled BCAA and AAA internal standar...

  17. On-line Determination of the Deuterium Abundance in Breath Water Vapour by Flowing Afterglow Mass Spectrometry with Applications to Measurements of Total Body Water

    Czech Academy of Sciences Publication Activity Database

    Španěl, Patrik; Smith, D.

    2001-01-01

    Roč. 15, č. 1 (2001), s. 25-32 ISSN 0951-4198 R&D Project s: GA ČR GA203/00/0632 Grant - others:Royal Society(GB) Joint project Institutional research plan: CEZ:AV0Z4040901 Keywords : flowing afterglow * mass spectrometry * stable isotopes Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.478, year: 2001

  18. Principle of accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Matsuzaki, Hiroyuki

    2007-01-01

    The principle of accelerator mass spectrometry (AMS) is described mainly on technical aspects: hardware construction of AMS, measurement of isotope ratio, sensitivity of measurement (measuring limit), measuring accuracy, and application of data. The content may be summarized as follows: rare isotope (often long-lived radioactive isotope) can be detected by various use of the ion energy obtained by the acceleration of ions, a measurable isotope ratio is one of rare isotope to abundant isotopes, and a measured value of isotope ratio is uncertainty to true one. Such a fact must be kept in mind on the use of AMS data to application research. (M.H.)

  19. Application of gamma spectrometry survey and discussion on data processing

    International Nuclear Information System (INIS)

    Li Ji'an; He Jianguo

    2008-01-01

    This paper analyzed and discussed the different opinions about the measured parameters of gamma spectrometry data, introduced the effect of gamma spectrometry survey to the search for sandstone type uranium deposit. The author believes that it is very necessary to perform some ground gamma spectrometry survey and enforce the development and application of airborne radiometric data so as to carry out the role of gamma spectrometry in the exploration of sandstone type uranium deposit. (authors)

  20. Nuclear energy. Waste-packages activity measurement. Part. 1: high-resolution gamma spectrometry in integral mode with open geometry; ISO 14850-1: 2004. Energie nucleaire -- Mesurage de l'activite de colis de dechets. Partie 1: Spectrometrie gamma haute resolution en mode integral et geometrie ouverte

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    ISO 14850:2004 describes a procedure for measurements of gamma-emitting radionuclide activity in homogeneous objects such as unconditioned waste (including process waste, dismantling waste, etc.), waste conditioned in various matrices (bitumen, hydraulic binder, thermosetting resins, etc.), notably in the form of 100 L, 200 L, 400 L or 800 L drums, and test specimens or samples, (vitrified waste), and waste packaged in a container, notably technological waste. It also specifies the calibration of the gamma spectrometry chain. The gamma energies used generally range from 0,05 MeV to 3 MeV.

  1. Nuclear energy - Waste-packages activity measurement - Part.1: high-resolution gamma spectrometry in integral mode with open geometry; ISO 14850-1:2004. Energie nucleaire - Mesurage de l'activite de colis de dechets - Partie 1: spectrometrie gamma haute resolution en mode integral et geometrie ouverte

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    ISO 14850:2004 describes a procedure for measurements of gamma-emitting radionuclide activity in homogeneous objects such as unconditioned waste (including process waste, dismantling waste, etc.), waste conditioned in various matrices (bitumen, hydraulic binder, thermosetting resins, etc.), notably in the form of 100 L, 200 L, 400 L or 800 L drums, and test specimens or samples, (vitrified waste), and waste packaged in a container, notably technological waste. It also specifies the calibration of the gamma spectrometry chain. The gamma energies used generally range from 0,05 MeV to 3 MeV. (authors)

  2. Hydrologic and geochemical controls on the transport of radionuclides in natural undisturbed arid environments as determined by accelerator mass spectrometry measurements

    International Nuclear Information System (INIS)

    Nimz, G; Caffee, M W; McAninch, J

    2000-01-01

    This project developed techniques for measuring globally distributed radionuclides that occur today in extremely low abundances (''fallout'' from the era of atmospheric nuclear testing), and then applied these techniques to better understand the mechanisms by which radionuclides migrate. The techniques employ accelerator mass spectrometry (AMS), a relatively new analytical tool that permits this work to be conducted for the first time. The goal in this project was to develop AMS analytical techniques for 129 I (fallout concentration: ∼ 10 6 atoms/g) 99 Tc (∼ 10 9 atoms/g), 90 Sr (∼10 7 atoms/gram soil), and 93 Zr (∼ 10 9 atoms/g), and improved methods for 36 Cl (∼ 10 9 atoms/g). As a demonstration of the analytical techniques, and as an investigation of identified problems associated with characterizing moisture and radionuclide movement in unsaturated desert soils, we developed a vadose zone research site at the Nevada Test Site. Our findings can be summarized as follows: (1) The distribution of chloride and 36 Cl at the research site indicates that the widely-used ''chloride accumulation'' method for estimating moisture flux is erroneous; some mechanism for attenuation of chloride exists, violating an assumption of the accumulation method; (2) 129 I is fractionated into several soil compartments that have varying migration abilities; the two most mobile can be tentatively identified as Fe/Mn oxyhydroxides and organic acids based on our sequential leaching techniques; (3) These most mobile constituents are capable of migrating at a rate greater than that of 36 Cl, usually considered the most mobile solute in hydrologic systems; these constituents may be colloidal in character, of neutral surface charge, and therefore conservative in aqueous migration; (4) 99 Tc is readily measurable by AMS, as we demonstrate by the first AMS 99 Tc measurements of contaminated waters; extraction of 99 Tc from silicate soils is difficult, but can be done using the extended

  3. Depth profiling of Pu, 241Am and 137Cs in soils from southern Belarus measured by ICP-MS and alpha and gamma spectrometry.

    Science.gov (United States)

    Boulyga, Sergei F; Zoriy, Myroslav; Ketterer, Michael E; Becker, J Sabine

    2003-08-01

    The depth distribution of plutonium, americium, and 137Cs originating from the 1986 accident at the Chernobyl Nuclear Power Plant (NPP) was investigated in several soil profiles in the vicinity from Belarus. The vertical migration of transuranic elements in soils typical of the 30 km relocation area around Chernobyl NPP was studied using inductively coupled plasma mass spectrometry (ICP-MS), alpha spectrometry, and gamma spectrometry. Transuranic concentrations in upper soil layers ranged from 6 x 10(-12) g g(-1) to 6 x 10(-10) g g(-1) for plutonium and from 1.8 x 10(-13) g g(-1) to 1.6 x 10(-11) g g(-1) for americium. These concentrations correspond to specific activities of (239+240)Pu of 24-2400 Bq kg(-1) and specific activity of 241Am of 23-2000 Bq kg(-1), respectively. Transuranics in turf-podzol soil migrate slowly to the deeper soil layers, thus, 80-95%, of radionuclide inventories were present in the 0-3 cm intervals of turf-podzol soils collected in 1994. In peat-marsh soil migration processes occur more rapidly than in turf-podzol and the maximum concentrations are found beneath the soil surface (down to 3-6 cm). The depth distributions of Pu and Am are essentially identical for a given soil profile. (239+240)Pu/137Cs and 241Am/137Cs activity ratios vary by up to a factor of 5 at some sites while smaller variations in these ratios were observed at a site close to Chernobyl, suggesting that 137Cs is dominantly particle associated close to Chernobyl but volatile species of 137Cs are of relatively greater importance at the distant sites.

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

    Science.gov (United States)

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

    2016-08-01

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

  5. Calibration and study of the measurement capabilities of real-time gamma spectrometry equipment developed for the renewal of the network of stations automatic monitoring environmental radiation of the Generalitat of Catalunya

    International Nuclear Information System (INIS)

    Casanovas, R.; Prieto, E.; Salvado, M.

    2014-01-01

    The renewal of the automatic environmental radiation surveillance network of the Generalitat of Catalunya has been carried out through the development and implementation of gamma-spectrometry-based equipment. the monitors use scintillation crystals, either Na(TI) or LaBr 3 (Ce) and currently, there are 3 types of equipment water radioactivity monitors, aerosols on a particulate filter monitors and direct measurement monitors. In this paper, we expose the basic features of its operation, the details of their calibration and the minimum detectable activity concentration for some isotopes. (Author)

  6. Calibration and study of the measurement capabilities of real-time gamma spectrometry equipment, developed for the renewal of the network of automatic stations for environmental radiological surveillance of the Generalitat de Catalunya

    International Nuclear Information System (INIS)

    Casanovas, R.; Prieto, E.; Salvado, M.

    2013-01-01

    The renewal of the automatic environmental radiation surveillance network of the Gereralitat of Catalunya has been carried out through the development and implementation of gamma-spectrometry-based equipment. The monitors use scintillation cristals, either NaI(Tl) or LaBr 3 (Ce) and currently, there are 3 types of equipment: water radioactivity monitors, aerosols on a particulate filter monitors and direct measurement monitors. In this paper, we expose the basic features of its operation, the details of their calibration and the minimum detectable activity concentrations for some isotopes

  7. Validation of methods to measure uranium isotopes using magnetic sector mass spectrometry with inductively coupled plasma source; Validacion de metodos para medir isotopos de uranio usando espectrometria de masas de sector magnetico con fuente de plasma acoplado inductivamente

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez M, H. [Universidad del Centro de Mexico, Capitan Caldera 75, Col. Tequixquiapan, 78250 San Luis Potosi, SLP (Mexico); Rios L, M. J. [Universidad Autonoma de San Luis Potosi, Facultad de Enfermeria y Nutricion, Unidad de Posgrado, Av. Nino Artillero 130, 78210 San Luis Potosi, SLP (Mexico); Romero G, E. T., E-mail: hector.hernandez520@gmail.com [ININ, Departamento de Quimica, Laboratorio Forense Nuclear, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2017-10-15

    The mass spectrometry technique with inductively coupled plasma source (Icp-Ms) has been widely used to measure isotopic ratios of elements toxic to human health. Reason for which, in this work several measurement methods for the analysis of uranium isotopes in different matrices were implemented using magnetic sector mass spectrometry with inductively coupled plasma source (Icp-SFMS). Groundwater, sediment, soil and urine were the matrices analyzed, which were supplied by intercomparison tests conducted by the IAEA and Association for the Promotion of Quality Control of Medical Biology Analysis in Radio-toxicology. The procedures used in the treatment of soil, sediment and water samples were based on US EPA methods. In the case of the urine sample, the preparation was rapid (1:20 dilution). The average of the results obtained in yield of each matrix was 94, 71, 72 and 78% for water, urine, soil and sediment respectively. In addition, the precision in terms of standard relative deviation was less than 5% and the accuracy was less than 4%. In conclusion, the Icp-SFMS is a very sensitive technique for measuring isotopes of U in different matrices. However, careful tuning is necessary, especially in the mass regions of interest 234, 235 and 238 if an external quantification is considered using natural U solutions. (Author)

  8. Pressure-assisted electrokinetic injection for on-line enrichment in capillary electrophoresis-mass spectrometry: a sensitive method for measurement of ten haloacetic acids in drinking water.

    Science.gov (United States)

    Zhang, Huijuan; Zhu, Jiping; Aranda-Rodriguez, Rocio; Feng, Yong-Lai

    2011-11-07

    Haloacetic acids (HAAs) are by-products of the chlorination of drinking water containing natural organic matter and bromide. A simple and sensitive method has been developed for determination of ten HAAs in drinking water. The pressure-assisted electrokinetic injection (PAEKI), an on-line enrichment technique, was employed to introduce the sample into a capillary electrophoresis (CE)-electrospray ionization-tandem mass spectrometry system (ESI-MS/MS). HAAs were monitored in selected reaction monitoring mode. With 3 min of PAEKI time, the ten major HAAs (HAA10) in drinking water were enriched up to 20,000-fold into the capillary without compromising resolution. A simple solid phase clean-up method has been developed to eliminate the influence of ionic matrices from drinking water on PAEKI. Under conditions optimized for mass spectrometry, PAEKI and capillary electrophoresis, detection limits defined as three times ratio of signal to noise have been achieved in a range of 0.013-0.12 μg L(-1) for ten HAAs in water sample. The overall recoveries for all ten HAAs in drinking water samples were between 76 and 125%. Six HAAs including monochloro- (MCAA), dichloro- (DCAA), trichloro- (TCAA), monobromo- (MBAA), bromochloro- (BCAA), and bromodichloroacetic acids (BDCAA) were found in tap water samples collected. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

  9. Accelerator mass spectrometry.

    Science.gov (United States)

    Hellborg, Ragnar; Skog, Göran

    2008-01-01

    In this overview the technique of accelerator mass spectrometry (AMS) and its use are described. AMS is a highly sensitive method of counting atoms. It is used to detect very low concentrations of natural isotopic abundances (typically in the range between 10(-12) and 10(-16)) of both radionuclides and stable nuclides. The main advantages of AMS compared to conventional radiometric methods are the use of smaller samples (mg and even sub-mg size) and shorter measuring times (less than 1 hr). The equipment used for AMS is almost exclusively based on the electrostatic tandem accelerator, although some of the newest systems are based on a slightly different principle. Dedicated accelerators as well as older "nuclear physics machines" can be found in the 80 or so AMS laboratories in existence today. The most widely used isotope studied with AMS is 14C. Besides radiocarbon dating this isotope is used in climate studies, biomedicine applications and many other fields. More than 100,000 14C samples are measured per year. Other isotopes studied include 10Be, 26Al, 36Cl, 41Ca, 59Ni, 129I, U, and Pu. Although these measurements are important, the number of samples of these other isotopes measured each year is estimated to be less than 10% of the number of 14C samples. Copyright 2008 Wiley Periodicals, Inc.

  10. Isotope dilution mass spectrometry as the primary method of measurement for the amount of matter. Application to cadmium determination in biological materials and comparison with instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Munoz, Luis; Gras, Nuri; Quejido, Alberto; Ferrada, Carlos

    2001-01-01

    A primary method of measurement as defined by the Consultative Committee on the Quantity of Matter (Comite Consultatif pour la Quantite de Matiere, CCQM) of the International Bureau of Weights and Measurements (Bureau International des Poids et Mesures, BIPM), is one whose measurement process is perfectly known, has valid theoretical foundations and is fully described and answers to an equation that relates what is measured with what is intended to be measured without any significant empirical correction factors. It is also a method that has insignificant systematic errors, where only magnitudes from the International System of Units (SI) are used and where, preferably, the uncertainties are small ones. They are, therefore, procedures that do not need instrumental calibration. The absolute methods of measurement allow a chain of traceability to be formed between the result obtained and the magnitude of the SI assigned to what is measured. So the results are said to be traceable to the SI. One of the methods that meets these requirements and is recognized as the primary method by the CCQM is Isotope Dilution Mass Spectrometry (IDMS). Through a project of Technical Cooperation with the International Atomic Energy Agency in the area of Chemical Metrology, the CCHEN obtained training in CIEMAT, Spain, in IDMS and its applications to the analysis of biological samples. This work describes the first experience carried out entirely in Chilean laboratories, applying IDMS to the determination of cadmium in the biological reference materials Oyster Tissue 15566-A from the NIST, United States, Dogfish Liver, DOLT-2 from the NRC-CNRC, Canada and Poplar Leaves GBW07604 from the NRCC, China. The samples were traced with an isotope enriched spike 111 Cd and then shaken to obtain the isotopic exchange. Once dissolved, the isotopic relationship 111 Cd/ 114 Cd was determined in the samples using mass spectrometry with plasma source. These results were compared with those obtained

  11. A REVIEW ON MASS SPECTROMETRY DETECTORS

    OpenAIRE

    Khatri Neetu; Gupta Ankit; Taneja Ruchi; Bilandi Ajay; Beniwal Prashant

    2012-01-01

    Mass spectrometry is an analytical technique for "weighing" molecules. Obviously, this is not done with a conventional scale or balance. Instead, mass spectrometry is based upon the principle of the motion of a charged particle that is called an ion, in an electric or magnetic field. The mass to charge ratio (m/z) of the ion affects particles motion. Since the charge of an electron is known, the mass to charge ratio (m/z) is a measurement of mass of an ion. Mass spectrometry research focuses ...

  12. Radionuclide content of simulated and fully radioactive SRLLL waste glasses: comparison of results from ICP-MS, gamma spectrometry and alpha spectrometry

    International Nuclear Information System (INIS)

    Wolf, S.F.; Bates, J.K.

    1995-01-01

    We have measured the transuranic content of two transuranic=doped, simulated waste glasses, using inductively coupled plasma-mass spectrometry (ICP-MS), γ-spectrometry, and α-spectrometry. Average concentrations measured by each technique were within ± 10% of the as-doped concentrations. We also report the transuranic content of three fully radioactive SRL waste glasses that were determined using γ- and α-spectrometry measurements to deconvolute isobaric interferences present in the ICP-MS analyses

  13. Evaluation of Aerosol Mixing State Classes in the GISS Modele-matrix Climate Model Using Single-particle Mass Spectrometry Measurements

    Science.gov (United States)

    Bauer, Susanne E.; Ault, Andrew; Prather, Kimberly A.

    2013-01-01

    Aerosol particles in the atmosphere are composed of multiple chemical species. The aerosol mixing state, which describes how chemical species are mixed at the single-particle level, provides critical information on microphysical characteristics that determine the interaction of aerosols with the climate system. The evaluation of mixing state has become the next challenge. This study uses aerosol time-of-flight mass spectrometry (ATOFMS) data and compares the results to those of the Goddard Institute for Space Studies modelE-MATRIX (Multiconfiguration Aerosol TRacker of mIXing state) model, a global climate model that includes a detailed aerosol microphysical scheme. We use data from field campaigns that examine a variety of air mass regimens (urban, rural, and maritime). At all locations, polluted areas in California (Riverside, La Jolla, and Long Beach), a remote location in the Sierra Nevada Mountains (Sugar Pine) and observations from Jeju (South Korea), the majority of aerosol species are internally mixed. Coarse aerosol particles, those above 1 micron, are typically aged, such as coated dust or reacted sea-salt particles. Particles below 1 micron contain large fractions of organic material, internally-mixed with sulfate and black carbon, and few external mixtures. We conclude that observations taken over multiple weeks characterize typical air mass types at a given location well; however, due to the instrumentation, we could not evaluate mass budgets. These results represent the first detailed comparison of single-particle mixing states in a global climate model with real-time single-particle mass spectrometry data, an important step in improving the representation of mixing state in global climate models.

  14. Alpha spectrometry and the secondary ion mass spectrometry of thorium

    International Nuclear Information System (INIS)

    Strisovska, J.; Kuruc, J.; Galanda, D.; Matel, L.; Aranyosiova, M.; Velic, D.

    2009-01-01

    The main objective of this master thesis was preparation of samples with thorium content on the steel discs by electrodeposition for determination of natural thorium isotope by alpha spectrometry and the secondary ion mass spectrometry and finding out their possible linear correlation between these methods. The samples with electrolytically excluded isotope of 232 Th were prepared by electrodeposition from solution Th(NO 3 ) 4 ·12 H2 O on steel discs in electrodeposition cell with use of solutions Na 2 SO 4 , NaHSO 4 , KOH and (NH 4 ) 2 (C 2 O 4 ) by electric current 0.75 A. Discs were measured by alpha spectrometer. Activity was calculated from the registered impulses for 232 Th and surface's weight. After alpha spectrometry measurements discs were analyzed by TOF-SIMS IV which is installed in the International Laser Centre in Bratislava. Intensities of isotope of 232 Th and ions of ThO + , ThOH + , ThO 2 H + , Th 2 O 4 H + , ThO 2 - , ThO 3 H - , ThH 3 O 3 - and ThN 2 O 5 H - were identified. The linear correlation is between surface's weights of Th and intensities of ions of Th + from SIMS, however the correlation coefficient has relatively low value. We found out with SIMS method that oxidized and hydride forms of thorium are significantly represented in samples with electroplated thorium. (authors)

  15. Performance Test of Alpha Spectrometry for Environmental Radioactivity Analysis

    International Nuclear Information System (INIS)

    Choi, Jung Youn; Yoon, Jong-Ho; Han, Ki-Tek; Ahn, Gil Hoon

    2015-01-01

    Environmental samples are analyzed by various methods such as, ICP-MS (inductively coupled plasma mass spectrometry), AMS (accelerator mass spectrometry) TIMS (thermal ionization mass spectrometry), HRGS (high resolution gamma spectrometry) and alpha /beta particle analysis. In this study, we will described the result of performance test using alpha spectrometry for analyzing environmental samples. Measurement data of the U activity using SRM based on extraction chromatography with UTEVA resin. It should be effective way to separate of uranium isotope for the measurement of alpha spectrometry. But, the result of this measurement data is higher than another recovery data. Also concentration of U data is lack of consistency. We leave out of consideration many effect of factors about influence in the experiment process. In the future work, we will try to reduce the step of experiment process and reflect the uncertainty factors

  16. Mass spectrometry of long-lived radionuclides

    International Nuclear Information System (INIS)

    Becker, Johanna Sabine.

    2003-01-01

    The capability of determining element concentrations at the trace and ultratrace level and isotope ratios is a main feature of inorganic mass spectrometry. The precise and accurate determination of isotope ratios of long-lived natural and artificial radionuclides is required, e.g. for their environmental monitoring and health control, for studying radionuclide migration, for age dating, for determining isotope ratios of radiogenic elements in the nuclear industry, for quality assurance and determination of the burn-up of fuel material in a nuclear power plant, for reprocessing plants, nuclear material accounting and radioactive waste control. Inorganic mass spectrometry, especially inductively coupled plasma mass spectrometry (ICP-MS) as the most important inorganic mass spectrometric technique today, possesses excellent sensitivity, precision and good accuracy for isotope ratio measurements and practically no restriction with respect to the ionization potential of the element investigated--therefore, thermal ionization mass spectrometry (TIMS), which has been used as the dominant analytical technique for precise isotope ratio measurements of long-lived radionuclides for many decades, is being replaced increasingly by ICP-MS. In the last few years instrumental progress in improving figures of merit for the determination of isotope ratio measurements of long-lived radionuclides in ICP-MS has been achieved by the application of a multiple ion collector device (MC-ICP-MS) and the introduction of the collision cell interface in order to dissociate disturbing argon-based molecular ions, to reduce the kinetic energy of ions and neutralize the disturbing noble gas ions (e.g. of 129 Xe + for the determination of 129 I). The review describes the state of the art and the progress of different inorganic mass spectrometric techniques such as ICP-MS, laser ablation ICP-MS vs. TIMS, glow discharge mass spectrometry, secondary ion mass spectrometry, resonance ionization mass

  17. Mechanism of [m+h]+ formation in atmospheric pressure photoionization mass spectrometry: identification of propionitrile in acetonitrile with high mass accuracy measurement and tandem mass spectrometry and evidence for its involvement in the protonation phenomenon.

    Science.gov (United States)

    Kamel, Amin; Jeanville, Patrick; Colizza, Kevin; J-Rivera, Lauren Elizabeth

    2008-11-01

    The role of propionitrile in the production of [M+H]+ under atmospheric pressure photoionization (APPI) was investigated. In dopant-assisted APPI using acetone and anisole, protonated acetone and anisole radical cations were the most prominent ions observed. In dopant-free or direct APPI in acetonitrile, however, a major ion in acetonitrile was detected and identified as propionitrile, using high accuracy mass measurement and collision induced dissociation studies. Vaporizing ca. 10(-5) M althiazide and bendroflumethazide under direct APPI in acetonitrile produced their corresponding protonated species [M+H]+. In addition to protonated acetonitrile, its dimers, and acetonitrile/water clusters, protonated propionitrile, propionitrile dimer, and propionitrile/water clusters were also observed. The role of propionitrile, an impurity in acetonitrile and/or a possible product of ion-molecule reaction, in the production of [M+H]+ of althiazide and bendroflumethazide was further investigated in the absence of dopant using propionitrile-d5. The formation of [M+D]+ species was observed, suggesting a possible role of propionitrile in the protonation process. Additionally, an increase in the [M+H]+ signal of althiazide and bendroflumethazide was observed as a function of propionitrile concentration in acetonitrile. Theoretical data from the literature supported the assumption that one possible mechanism, among others, for the formation of [M+H]+ could be attributed to photo-initiated isomerization of propionitrile. The most stable isomers of propionitrile, based on their calculated ionization energy (IE) and relative energy (DeltaE), were assumed to undergo proton transfer to the analytes, and mechanisms were proposed.

  18. Contribution to the study of luminous sources for uranium isotope measurements by emission spectrometry; Contribution a l'etude de sources lumineuses destinees au dosage isotopique de l'uranium par spectrometrie d'emission

    Energy Technology Data Exchange (ETDEWEB)

    Leichnam, J P; Capitini, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    After a brief summary of results obtained with different hollow cathode luminous sources, the reasons for which they cannot be more widely used are given: an insufficient luminosity when uranium oxides are used in the cathode hollow; the large amount of sample required when it is metallic; the impossibility of effecting a chemical purification of the sample. Electrode-less discharge tubes excited by high frequency whose qualities (luminosity, stability, rapidity of preparation starting from small amounts of sample in various chemical forms, in particular iron) satisfy the conditions laid down for the measurement of uranium 235 by interferometry are used. Tho production process for such lamps is given together with the method of excitation. Examples of recordings obtained with an interferometer of the 'HYPEAC' type and a small grating spectrometer give an idea of the spectral qualities of these sources. (authors) [French] Apres avoir rappele les resultats obtenus avec differentes sources de lumiere a cathode creuse, on explique les raisons qui limitent leur emploi: brillance trop faible lorsque les oxydes d'uranium sont utilises dans le trou cathodique; trop grande quantite d'echantillon necessaire lorsque celui-ci est sous forme metallique; impossibilite de purifier chimiquement l'echantillon. On a employe des tubes a decharge sans electrode excitee par haute frequence, dont les qualites (brillance, stabilite, rapidite de preparation a partir de faibles quantites d'echantillon se presentant sous des formes chimiques diverses, elimination des impuretes chimiques, en particulier du fer) repondent aux conditions imposees pour le dosage isotopique de l'uranium 235 par interferometrie. On decrit le mode operatoire de fabrication de telles lampes et on rappelle le systeme d'excitation. Des exemples d'enregistrement, obtenus avec un appareil interferometrique 'HYPEAC' et un petit spectrometre a reseau, donnent une idee des qualites spectrales de ces sources. (auteurs)

  19. Development of an analytical strategy based on liquid chromatography-high resolution mass spectrometry for measuring perfluorinated compounds in human breast milk: application to the generation of preliminary data regarding perinatal exposure in France.

    Science.gov (United States)

    Kadar, Hanane; Veyrand, Bruno; Barbarossa, Andrea; Pagliuca, Giampiero; Legrand, Arnaud; Bosher, Cécile; Boquien, Clair-Yves; Durand, Sophie; Monteau, Fabrice; Antignac, Jean-Philippe; Le Bizec, Bruno

    2011-10-01

    Perfluorinated compounds (PFCs) are man-made chemicals for which endocrine disrupting properties and related possible side effects on human health have been reported, particularly in the case of an exposure during the early stages of development, (notably the perinatal period). Existing analytical methods dedicated to PFCs monitoring in food and/or human fluids are currently based on liquid chromatography coupled to tandem mass spectrometry, and were recently demonstrated to present some limitations in terms of sensitivity and/or specificity. An alternative strategy dedicated to the analysis of fourteen PFCs in human breast milk was proposed, based on an effective sample preparation followed by a liquid chromatography coupled to high resolution mass spectrometry measurement (LC-HRMS). This methodology confirmed the high interest for HRMS after negative ionization for such halogenated substances, and finally permitted to reach detection limits around the pg mL(-1) range with an outstanding signal specificity compared to LC-MS/MS. The proposed method was applied to a first set of 30 breast milk samples from French women. The main PFCs detected in all these samples were PFOS and PFOA with respective median values of 74 (range from 24 to 171) and 57 (range from 18 to 102) pg mL(-1), respectively. These exposure data appeared in the same range as other reported values for European countries. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. Acid-yield measurements of the gas-phase ozonolysis of ethene as a function of humidity using Chemical Ionisation Mass Spectrometry (CIMS

    Directory of Open Access Journals (Sweden)

    K. E. Leather

    2012-01-01

    Full Text Available Gas-phase ethene ozonolysis experiments were conducted at room temperature to determine formic acid yields as a function of relative humidity (RH using the integrated EXTreme RAnge chamber-Chemical Ionisation Mass Spectrometry technique, employing a CH3I ionisation scheme. RHs studied were <1, 11, 21, 27, 30 % and formic acid yields of (0.07±0.01 and (0.41±0.07 were determined at <1 % RH and 30 % RH respectively, showing a strong water dependence. It has been possible to estimate the ratio of the rate coefficient for the reaction of the Criegee biradical, CH2OO with water compared with decomposition. This analysis suggests that the rate of reaction with water ranges between 1×10−12–1×10−15 cm3 molecule−1 s−1 and will therefore dominate its loss with respect to bimolecular processes in the atmosphere. Global model integrations suggest that this reaction between CH2OO and water may dominate the production of HC(OOH in the atmosphere.

  1. High-precision 13C and 18O measurements by continuous flow-isotope ratio mass spectrometry (CF-IRMS) in Romanian wines characterization

    International Nuclear Information System (INIS)

    Costinel, Diana; Ionete, Roxana; Vremera, Raluca; Stanciu, Vasile

    2008-01-01

    Wines characterization is an important problem to which isotopic analysis by continuous flow- IRMS has made a significant contribution. The use of mass spectrometry (MS) to determine the ratios of stable isotopes in bio-molecules now provides the means to prove the botanical and geographical origin of a wide variety of foodstuffs - and therefore, to authenticate and eliminate fraud. There is a strong need for reliable and validated methods to ensure compliance with such regulation and to protect the interests of the consumer. The right to producing wines with an appellation of origin is guaranteed by the Ministry of Agriculture, based on proposals made by the National Office of Vine and Wine (starting with the 1993 vintage year). The Ministry of Agriculture, the National Office for Vine and Wine, and the National Research Institute grants the authentication of the wines with appellation of origin. The present paper emphasize the isotopic analysis for 18 O/ 16 O and 13 C/ 12 C from wines, using a new generation Isotope Ratio MS, CF-IRMS Delta V Plus, coupled with three flexible continuous flow preparation devices (GasBench II and TC Elemental Analyser). (authors)

  2. Urban gamma spectrometry. Report 2

    Energy Technology Data Exchange (ETDEWEB)

    Aage, H.K. (Technical Univ. of Denmark, Kgs. Lyngby (Denmark)); Kuukankorpi, S.; Moring, M.; Smolander, P.; Toivonen, H. (Radiation and Nuclear Safety Authority, Helsinki (Finland))

    2009-06-15

    Urban gamma spectrometry has been given only minor attention with the focus being on rural gamma spectrometry. However, in recent years the Nordic emergency management authorities have turned focus towards border control and lost or stolen sources. Gamma spectra measured in urban areas are characterized by a wide variety of spectrum shapes and very fast changes in environmental background. In 2004 a Danish CGS (Carborne Gamma Spectrometry) survey took place in Copenhagen. It was found that gamma spectrometry in urban areas is far more complicated to interpret than had previously been thought and a new method 'Fitting with Spectral Components', FSC, based on NASVD, was tested with some success. In Finland, a database 'LINSSI' has been developed for spectral data management. In CGS search mode a 'peak hypothesis test' is applied to the measured spectra. This system was tested during the Helsinki 2005 Athletics World Championship and it provides fast and reliable automated alarms for intermediate and high level signals. In Sweden mobile detector systems are used for border controls and problems are encountered when making measurement in harbour, container areas. The methods for handling data and for interpretation of urban gamma spectrometry measurements were compared and tested on the same data sets from Copenhagen and Helsinki. Software tools were developed for converting data between the Finnish LINSSI database and the binary file formats used in Denmark and Sweden. The Processing methods used at DTU and STUK have different goals. The ASSS and FSC methods are designed to optimize the overall detection capability of the system, while sacrificing speed, usability and to a certain level robustness. These methods cannot always be used for real time analysis. The Peak Significance method is designed to give robust alarms in real time, while sacrificing some of the detection capability. Thus these methods are not interchangeable, but rather

  3. Urban gamma spectrometry. Report 2

    International Nuclear Information System (INIS)

    Aage, H.K.; Kuukankorpi, S.; Moring, M.; Smolander, P.; Toivonen, H.

    2009-06-01

    Urban gamma spectrometry has been given only minor attention with the focus being on rural gamma spectrometry. However, in recent years the Nordic emergency management authorities have turned focus towards border control and lost or stolen sources. Gamma spectra measured in urban areas are characterized by a wide variety of spectrum shapes and very fast changes in environmental background. In 2004 a Danish CGS (Carborne Gamma Spectrometry) survey took place in Copenhagen. It was found that gamma spectrometry in urban areas is far more complicated to interpret than had previously been thought and a new method 'Fitting with Spectral Components', FSC, based on NASVD, was tested with some success. In Finland, a database 'LINSSI' has been developed for spectral data management. In CGS search mode a 'peak hypothesis test' is applied to the measured spectra. This system was tested during the Helsinki 2005 Athletics World Championship and it provides fast and reliable automated alarms for intermediate and high level signals. In Sweden mobile detector systems are used for border controls and problems are encountered when making measurement in harbour, container areas. The methods for handling data and for interpretation of urban gamma spectrometry measurements were compared and tested on the same data sets from Copenhagen and Helsinki. Software tools were developed for converting data between the Finnish LINSSI database and the binary file formats used in Denmark and Sweden. The Processing methods used at DTU and STUK have different goals. The ASSS and FSC methods are designed to optimize the overall detection capability of the system, while sacrificing speed, usability and to a certain level robustness. These methods cannot always be used for real time analysis. The Peak Significance method is designed to give robust alarms in real time, while sacrificing some of the detection capability. Thus these methods are not interchangeable, but rather complementary. An ideal system

  4. Langmuir probe measurements and mass spectrometry of plasma plumes generated by laser ablation of La{sub 0.4}Ca{sub 0.6}MnO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jikun; Lippert, Thomas, E-mail: Thomas.lippert@psi.ch; Ojeda-G-P, Alejandro; Stender, Dieter; Schneider, Christof W.; Wokaun, Alexander [Department of General Energy Research, Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Lunney, James G. [School of Physics and CRANN, Trinity College, Dublin 2 (Ireland)

    2014-08-21

    The plasma formed in vacuum by UV nanosecond laser ablation of La{sub 0.4}Ca{sub 0.6}MnO{sub 3} in the fluence range of 0.8 to 1.9 J cm{sup −2} using both Langmuir probe analysis and energy-resolved mass spectrometry has been studied. Mass spectrometry shows that the main positive ion species are Ca{sup +}, Mn{sup +}, La{sup +}, and LaO{sup +}. The Ca{sup +} and Mn{sup +} energy distributions are quite broad and lie in the 0–100 eV region, with the average energies increasing with laser fluence. In contrast, the La{sup +} and LaO{sup +} distributions are strongly peaked around 10 eV. The net time-of-arrival signal derived from the measured positive ion energy distributions is broadly consistent with the positive ion signal measured by the Langmuir probe. We also detected a significant number of O{sup −} ions with energies in the range of 0 to 10 eV. The Langmuir probe was also used to measure the temporal variation of the electron density and temperature at 6 cm from the ablation target. In the period when O{sup −} ions are found at this position, the plasma conditions are consistent with those required for significant negative oxygen ion formation, as revealed by studies on radio frequency excited oxygen plasma.

  5. Atomic mass spectrometry

    International Nuclear Information System (INIS)

    Sanz-Medel, A.

    1997-01-01

    The elemental inorganic analysis seems to be dominated today by techniques based on atomic spectrometry. After an evaluation of advantages and limitations of using mass analysers (ion detectors) versus conventional photomultipliers (photon detector) a brief review of the more popular techniques of the emerging Atomic Mass spectrometry is carried out. Their huge potential for inorganic trace analysis is such that in the future we could well witness how this end of the century and millennium marked the fall of the photons empire in Analytical Atomic Spectrometry. (Author)

  6. Atomic electron spectrometry with synchrotron radiation

    International Nuclear Information System (INIS)

    Sorensen, S.L.

    1989-01-01

    Techniques of atomic electron spectrometry were applied to atoms in the gaseous and solid states to derive information about fundamental atomic properties. A new method was developed to measure Coster-Kronig yields in metals by photoionization with synchrotron radiation. Photon-energy sensitive Si L-VV Auger satellites were investigated via electron spectrometry. The krypton 1s photoionization spectrum was measured in an experiment which was motivated by the need to understand the krypton 1s satellite spectrum for calibration of an experiment to measure the mass of the electron antineutrino

  7. Correcting the effects of the matrix using capture gamma-ray spectrometry: Application to measurement by Active Neutron Interrogation; Correction des effets de matrice par spectrometrie des rayonnements gamma de capture: Application a la mesure par Interrogation Neutronique Active (I.N.A.)

    Energy Technology Data Exchange (ETDEWEB)

    Baudry, G.

    2003-11-15

    In the field of the measurement of low masses of fissile material ({sup 235}U, {sup 239}Pu, {sup 241}Pu) in radioactive waste drums, the Active Neutron Interrogation is a non-destructive method achieving good results. It does however remain reliant upon uncertainties related to the matrix effects on interrogation and fission neutrons. The aim of this thesis is to develop a correction method able to take into account these matrix effects by quantifying the amount of absorbent materials (chlorine and hydrogen) in a 118- liter homogeneous matrix. The main idea is to use the gamma-ray spectrometry of gamma emitted by neutron captures to identify and quantify the composition of the matrix. An indicator from its chlorine content is then deduced in order to choose the calibration coefficient which best represents the real composition of the matrix. This document firstly presents the needs of control and characterization of radioactive objects, and the means used in the field of nuclear measurement. Emphases is put in particular on the Active Neutron Interrogation method. The matrices of interest are those made of light technological waste (density {<=} 0,4 g/cm{sup 3}) containing hydrogenated and chlorinated materials. The advantages of gamma-rays emitted by neutron captures for the determination of a chlorine content indicator of the matrices and the principles of the correction method are then explained. Measurements have been firstly realized with an existing Neutron Interrogation device (PROMETHEE 6). Such measurements have proven its inadequacy: no signal from the matrix hydrogen was detected, due to an intense signal from the polyethylene contained in some cell elements. Moreover, the matrix chlorine content appeared difficult to be measured. A new and specific device, named REGAIN and dedicated to active gamma-rays spectrometry, was defined with the Monte-Carlo N-Particle (MCNP) code. The experiments conducted with this new device made it possible to detect the

  8. Meconium Nicotine and Metabolites by Liquid Chromatography–Tandem Mass Spectrometry: Differentiation of Passive and Nonexposure and Correlation with Neonatal Outcome Measures

    Science.gov (United States)

    Gray, Teresa R.; Magri, Raquel; Shakleya, Diaa M.; Huestis, Marilyn A.

    2011-01-01

    BACKGROUND Meconium analysis is a diagnostically sensitive and objective alternative to maternal self-report for detecting prenatal tobacco exposure. Nicotine and metabolite disposition in meconium is poorly characterized, and correlation of analytes’ concentrations with neonatal outcomes is unexplored. Our objectives were to quantify nicotine, cotinine, trans-3′-hydroxycotinine (OH-cotinine), nornicotine, norcotinine, and glucuronide concentrations in meconium, identify the best biomarkers of in utero tobacco exposure, compare meconium concentrations of tobacco-exposed and nonexposed neonates, and investigate concentration–outcome relationships. METHODS We quantified concentrations of nicotine and 4 metabolites with and without hydrolysis simultaneously in meconium from tobacco-exposed and nonexposed neonates by liquid chromatography–tandem mass spectrometry. We compared meconium concentrations to birth weight, length, head circumference, gestational age, and 1- and 5-min Apgar scores. RESULTS Nicotine, cotinine, and OH-cotinine were the most prevalent and abundant meconium tobacco biomarkers and were found in higher concentrations in tobacco-exposed neonates. Whereas cotinine and OH-cotinine are glucuronide bound, performing the lengthy and costly enzymatic hydrolysis identified only 1 additional positive specimen. Unconjugated nicotine, cotinine, or OH-cotinine meconium concentration >10 ng/g most accurately discriminated active from passive and nonexposed neonates. There was no significant correlation between quantitative nicotine and metabolite meconium results and neonatal outcomes, although presence of a nicotine biomarker predicted decreased head circumference. CONCLUSIONS Unconjugated nicotine, cotinine, and OH-cotinine should be analyzed in meconium to detect in utero tobacco exposure, as approximately 25% of positive specimens did not contain cotinine. Immunoassay testing monitoring cotinine only would underestimate the prevalence of prenatal

  9. Software for nuclear spectrometry

    International Nuclear Information System (INIS)

    1998-10-01

    The Advisory Group Meeting (AGM) on Software for Nuclear Spectrometry was dedicated to review the present status of software for nuclear spectrometry and to advise on future activities in this field. Because similar AGM and consultant's meetings had been held in the past; together with an attempt to get more streamlined, this AGM was devoted to the specific field of software for gamma ray spectrometry. Nevertheless, many of the issues discussed and the recommendations made are of general concern for any software on nuclear spectrometry. The report is organized by sections. The 'Summary' gives conclusions and recommendations adopted at the AGM. These conclusions and recommendations resulted from the discussions held during and after presentations of the scientific and technical papers. These papers are reported here in their integral form in the following Sections

  10. Measurement by γ spectrometry of specific activities of radioisotopes present in vegetal ashes. Study of variations of the ambient radioactivity level in the Grenoble transverse valley from March 1966 to August 1968

    International Nuclear Information System (INIS)

    Chevalier, Michel; Guitton, Pierre; Gagnaire, Janine; Ferard, Guy; Plebin, Roger; LACHET, Bernard

    1969-08-01

    The first part of this report addresses the dosimetry of γ emitting radio-elements which are present in vegetal samples. The dose measurements were performed by spectrometry and results were processed by using a least square method. The second part reports works performed in the Grenoble transverse valley by using the same techniques. Radioactivity fluctuations of various radio-elements ( 40 K, 54 Mn, 95 Zr + 95 Nb, 103 Ru + 106 Rh, 137 Cs, 137 Ba, 140 Ba + 140 La, 144 Ce + 144 Pr) in various vegetal species, in water and in sediments have been monitored in seven points of the Isere river banks, upstream and downstream the city of Grenoble, from March 1966 to August 1968. Fluctuations observed for each radio-element are explained by comparison with physiologic, hydrologic and atmospheric climate conditions. The principles of a systematic control of a site for the detection of possible radioactive pollutions are then defined [fr

  11. Mass spectrometry in nuclear science and technology

    International Nuclear Information System (INIS)

    Komori, Takuji

    1985-01-01

    Mass spectrometry has been widely used and playing a very important role in the field of nuclear science and technology. A major reason for this is that not only the types of element but also its isotopes have to be identified and measured in this field. Thus, some applications of this analytical method are reviewed and discussed in this article. Its application to analytical chemistry is described in the second section following an introductory section, which includes subsections for isotropic dilution mass spectrometry, resonance ionization mass spectrometry and isotopic correlation technique. The isotopic ratio measurement for hydrogen, uranium and plutonium as well as nuclear material control and safeguards are also reviewed in this section. In the third section, mass spectrometry is discussed in relation to nuclear reactors, with subsections on natural uranium reactor and neutron flux observation. Some techniques for measuring the burnup fraction, including the heavy isotopic ratio method and fission product monitoring, are also described. In the fourth section, application of mass spectrometry to measurement of nuclear constants, such as ratio of effective cross-sectional area for 235 U, half-life and fission yield is reviewed. (Nogami, K.)

  12. Glycomics using mass spectrometry

    OpenAIRE

    Wuhrer, Manfred

    2013-01-01

    Mass spectrometry plays an increasingly important role in structural glycomics. This review provides an overview on currently used mass spectrometric approaches such as the characterization of glycans, the analysis of glycopeptides obtained by proteolytic cleavage of proteins and the analysis of glycosphingolipids. The given examples are demonstrating the application of mass spectrometry to study glycosylation changes associated with congenital disorders of glycosylation, lysosomal storage di...

  13. Ion mobility spectrometry

    CERN Document Server

    Eiceman, GA

    2005-01-01

    Key Developments for Faster, More Precise Detection Capabilities Driven by the demand for the rapid and advanced detection of explosives, chemical and biological warfare agents, and narcotics, ion mobility spectrometry (IMS) undergone significant refinements in technology, computational capabilities, and understanding of the principles of gas phase ion chemistry and mobility. Beginning with a thorough discussion of the fundamental theories and physics of ion mobility, Ion Mobility Spectrometry, Second Edition describes the recent advances in instrumentation and newly

  14. Instrumentation for mass spectrometry: 1997

    Energy Technology Data Exchange (ETDEWEB)

    McLuckey, S.A.

    1997-08-01

    All mass spectrometry experiments involve the manipulation of material, an interface with the mass spectrometer, ionization, ion manipulation/analysis, detection and data collection/reduction. Each of these elements involve instrumentation. The wide range of species now amenable to mass spectrometry and the diverse areas of physical science in which it plays a role have led to a seemingly unlimited array of instrumental combinations. However, only a limited number of mass analyzers, and their combinations, dominate. The dominant analyzers include time-of-flight, Fourier transform ion cyclotron resonance, the Paul trap, the mass filter, and the sector mass spectrometer. Why there are so few (or so many, depending upon one`s point of view) can be understood upon consideration of a set of mass analyzer figures of merit. These include mass resolution, mass accuracy, mass range, dynamic range, abundance sensitivity, precision, efficiency, speed, MS{sup n} capability, compatibility with the ionizer, cost, and size. The most appropriate form of mass spectrometry is determined by the priorities of the particular measurement placed on the various mass analyzer characteristics and the relative strengths of the analyzers in meeting the requirements. Each of the analyzer types has a unique set of figures of merit that makes it optimally suited for particular applications. This paper discusses these figures of merit, provides data illustrating recent developments for each analyzer type, and gives the figures of merit of each type of analyzer as they stand in 1997. 101 refs., 24 figs.

  15. Optimization of Flame Atomic Absorption Spectrometry for ...

    African Journals Online (AJOL)

    Optimization of Flame Atomic Absorption Spectrometry for Measurement of High Concentrations of Arsenic and Selenium. ... This procedure allowed a rapid determination of As from minimum 4.462 mg/L to higher concentrations without sample pretreatment. Besides As, this method successfully measured Se concentrations ...

  16. RadNet Real-Time Monitoring Spectrometry Data Inventory

    Data.gov (United States)

    U.S. Environmental Protection Agency — The RadNet Real-Time Monitoring Spectrometry Data Inventory contains measured data used to identify and measure specific radioactive materials in the atmosphere at...

  17. Measurement of serum 3-epi-25-hydroxyvitamin D3, 25-hydroxyvitamin D3 and 25-hydroxyvitamin D2 in infant, paediatric and adolescent populations of Korea using ultra-performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Cho, Sung E; Kim, Sollip; Kim, Young D; Lee, Hyojung; Seo, Dong H; Song, Junghan; Um, Tae H; Cho, Chong R; Kim, Nam H; Hwang, Jong H

    2017-09-01

    Background We evaluated the performance of ultra-performance liquid chromatography-tandem mass spectrometry to measure serum 3-epi-25-hydroxyvitamin D 3 , 25-hydroxyvitamin D 3 and 25-hydroxyvitamin D 2 concentrations in 519 infant, paediatric and adolescent serum samples in Korea. Methods We used a Kinetex XB-C18 column and isocratic methanol/water (77.5/22.5, v/v) with 0.025% (v/v) high-performance liquid chromatography solvent additive flowing at 0.25 mL/min, yielding an 11 min/sample run time. A TQD triple quadrupole mass spectrometer in electrospray ionization positive ion mode with multiple reaction monitoring transition via an MSMS vitamin D kit was used to evaluate precision, carryover, ion suppression and linearity. Samples were prepared using the 4-phenyl-1,2,4-triazoline-3,5-dione derivatization method. Results Intra- and inter-run precisions were 1.23-13.28% and 1.02-10.08%, respectively. Group carryovers were -0.27% and 0.10%, respectively. There was no ion suppression. The calibration curve showed good linearity from calibrator Level 1 (11.75 nmol/L) to 6 (375 nmol/L) with R 2  > 0.9999. The 3-epi-25-hydroxyvitamin D 3 and 25-hydroxyvitamin D 3 peaks were clearly separated in the extracted ion chromatogram. Infant serum samples 3-epi-25-hydroxyvitamin D 3 concentrations were significantly higher than paediatric and adolescent concentrations. Conclusions The ultra-performance liquid chromatography-tandem mass spectrometry assay performed acceptably, clearly separating 3-epi-25-hydroxyvitamin D 3 from 25-hydroxyvitamin D 3 . High 3-epi-25-hydroxyvitamin D 3 concentrations were observed in infant but not in paediatric and adolescent serum samples.

  18. Systematic profiling and comparison of the lipidomes from Panax ginseng, P. quinquefolius, and P. notoginseng by ultrahigh performance supercritical fluid chromatography/high-resolution mass spectrometry and ion mobility-derived collision cross section measurement.

    Science.gov (United States)

    Shi, Xiaojian; Yang, Wenzhi; Qiu, Shi; Hou, Jinjun; Wu, Wanying; Guo, Dean

    2018-05-04

    Lipidomics currently is still confronted with challenges from chromatographic separation and lipids identification. Here we report a lipidomics platform by integrating ultrahigh performance supercritical fluid chromatography/quadrupole time-of-flight mass spectrometry (UHPSFC/QTOF-MS) and collision cross section (CCS) measurement using ion mobility spectroscopy/time-of-flight mass spectrometry (IMS/QTOF-MS), aiming to enhance the profiling performance and identification reliability of lipids. The lipidomes extracted from three congeneric Panax species (P. ginseng, P. quinquefolius, and P. notoginseng) by methyl tert-butyl ether are comprehensively profiled and compared by use of this platform. A potent UHPSFC/QTOF-MS approach was developed on a 1.7-μm particles packed Torus 2-PIC column using CH 3 OH (in CO 2 ) as a modifier and CH 3 OH/0.2 mM ammonium acetate as the makeup liquid, enabling well resolution of six lipid subclasses by both positive and negative MS E modes. In contrast to the reversed-phase chromatography, "normal-phase" like elution order and better resolution of polar lipids and some lipid isomers were achieved by UHPSFC separation. Pattern recognition chemometric analysis of 60 batches of Ginseng samples ultimately unveiled 24 lipid markers, of which triacylglycerols were the most important. Aside from the automated MS database searching against HMDB and LIPID MAPS, the application of CCS retrieval or CCS prediction improved lipid identification by reducing the possible hits. In conclusion, this integral platform can significantly improve the chromatographic separation and the reliability of lipids identification in lipidomics studies. It is the first report that systematically compares the lipidomic difference of three reputable Panax species, providing useful information for their quality control in addition to ginsenoside analysis. Copyright © 2018 Elsevier B.V. All rights reserved.

  19. Advanced β-ray-induced X-ray spectrometry for non-destructive measurement of tritium retained in fusion related materials

    Energy Technology Data Exchange (ETDEWEB)

    Matsuyama, Masao, E-mail: matsu3h@ctg.u-toyama.ac.jp; Abe, Shinsuke

    2016-11-01

    Highlights: • A new measurement system to measure low-Z elements such as C and O atoms has been constructed for evaluation of tritium trapped by these elements. - Abstract: A new β-ray-induced X-ray measurement system equipped with a silicon drift detector, which was named “Advanced-BIXS”, was constructed to study in detail retention behavior of surface tritium by measurements of low energy X-rays below 1 keV such as C(K{sub α}) and O(K{sub α}) as well as high energy X-rays induced by β-rays from tritium. In this study, basic performance of the present system has been examined using various tritium-containing samples. It was seen that energy linearity, energy resolution and sensitivity were quite enough for measurements of low energy X-rays induced by β-rays. Intensity of characteristic X-rays emitted from the surface and/or bulk of a tritium-containing sample was lowered by argon used as a working gas of the Advanced-BIXS. Pressure dependence of transmittance of C(K{sub α}) and Fe(K{sub α}) was examined as examples of low and high energy X-rays, and it was able to represent by using the mass absorption coefficient in argon. It was concluded, therefore, that the present system has high potentiality for nondestructive measurements of tritium retained in surface layers and/or bulk of fusion related materials.

  20. Method for the elucidation of the elemental composition of low molecular mass chemicals using exact masses of product ions and neutral losses: application to environmental chemicals measured by liquid chromatography with hybrid quadrupole/time-of-flight mass spectrometry.

    Science.gov (United States)

    Suzuki, Shigeru; Ishii, Tetsuko; Yasuhara, Akio; Sakai, Shinichi

    2005-01-01

    A method for elucidating the elemental compositions of low molecular weight chemicals, based primarily on mass measurements made using liquid chromatography (LC) with time-of-flight mass spectrometry (TOFMS) and quadrupole/time-of-flight mass spectrometry (LC/QTOFMS), was developed and tested for 113 chemicals of environmental interest with molecular masses up to approximately 400 Da. As the algorithm incorporating the method is not affected by differences in the instrument used, or by the ionization method and other ionization conditions, the method is useful not only for LC/TOFMS, but also for all kinds of mass spectra measured with higher accuracy and precision (uncertainties of a few mDa) employing all ionization methods and on-line separation techniques. The method involves calculating candidate compositions for intact ionized molecules (ionized forms of the sample molecule that have lost or gained no more than a proton, i.e., [M+H](+) or [M-H](-)) as well as for fragment ions and corresponding neutral losses, and eliminating those atomic compositions for the molecules that are inconsistent with the corresponding candidate compositions of fragment ions and neutral losses. Candidate compositions were calculated for the measured masses of the intact ionized molecules and of the fragment ions and corresponding neutral losses, using mass uncertainties of 2 and 5 mDa, respectively. Compositions proposed for the ionized molecule that did not correspond to the sum of the compositions of a candidate fragment ion and its corresponding neutral loss were discarded. One, 2-5, 6-10, 11-20, and >20 candidate compositions were found for 65%, 39%, 1%, 1%, and 0%, respectively, for the 124 ionized molecules formed from the 113 chemicals tested (both positive and negative ions were obtained from 11 of the chemicals). However, no candidate composition was found for 2% of the test cases (i.e., 3 chemicals), for each of which the measured mass of one of the product ions was in

  1. Forensic Mass Spectrometry

    Science.gov (United States)

    Hoffmann, William D.; Jackson, Glen P.

    2015-07-01

    Developments in forensic mass spectrometry tend to follow, rather than lead, the developments in other disciplines. Examples of techniques having forensic potential born independently of forensic applications include ambient ionization, imaging mass spectrometry, isotope ratio mass spectrometry, portable mass spectrometers, and hyphenated chromatography-mass spectrometry instruments, to name a few. Forensic science has the potential to benefit enormously from developments that are funded by other means, if only the infrastructure and personnel existed to adopt, validate, and implement the new technologies into casework. Perhaps one unique area in which forensic science is at the cutting edge is in the area of chemometrics and the determination of likelihood ratios for the evaluation of the weight of evidence. Such statistical techniques have been developed most extensively for ignitable-liquid residue analyses and isotope ratio analysis. This review attempts to capture the trends, motivating forces, and likely impact of developing areas of forensic mass spectrometry, with the caveat that none of this research is likely to have any real impact in the forensic community unless: (a) The instruments developed are turned into robust black boxes with red and green lights for positives and negatives, respectively, or (b) there are PhD graduates in the workforce who can help adopt these sophisticated techniques.

  2. Evaluation of uncertainty and detection limits in 210Pb and 210Po measurement in water by alpha spectrometry using 210Po spontaneous deposition onto a silver disk

    International Nuclear Information System (INIS)

    Fernández, Pedro L.; Gómez, José; Ródenas, Carmen

    2012-01-01

    An easy and accurate method for the determination of 210 Pb and 210 Po in water using 210 Po spontaneous deposition onto a silver disk is proposed and assessed for its detection capabilities according to the ISO Guide for the expression of uncertainty in measurement (GUM) and ISO Standard 11929-7 concerning the evaluation of the characteristic limits for ionizing radiation measurements. The method makes no assumption on the initial values of the activity concentrations of 210 Pb, 210 Bi and 210 Po in the sample to be analyzed, and is based on the alpha spectrometric measurement of 210 Po in two different aliquots: the first one measured five weeks after the sampling date to ensure radioactive equilibrium between 210 Pb and 210 Bi and the second after a sufficient time for the ingrowth of 210 Po from 210 Pb to be significant. As shown, for a recommended time interval of seven months between 210 Po measurements, the applicability of the proposed method is limited to water samples with a 226 Ra to 210 Pb activity ratio C Ra /C Pb ≤4, as usual in natural waters. Using sample and background counting times of 24 h and 240 h, respectively, the detection limit of the activity concentration of each radionuclide at the sampling time for a 1 L sample typically varies between 0.7 and 16 mBq L −1 for 210 Pb in water samples with an initial activity of 210 Po in the range 0–200 mBq L −1 , and between 0.6 and 8.5 mBq L −1 for 210 Po in water samples with an initial activity of 210 Pb in the same range. - Highlights: ► 210 Pb and 210 Po measurement in water by 210 Po spontaneous deposition onto silver disks. ► 210 Pb and 210 Po determination based on 210 Po measurement in two different aliquots. ► Evaluation of characteristic limits in radioactivity measurements using ISO 11929-7. ► 10 Pb - 210 Po detection limits decrease with time elapsed between 210 Po measurements.

  3. Investigations on the properties of gas telescopes with three-piece measuring volume concerning their application for the spectrometry of fast neutrons

    International Nuclear Information System (INIS)

    Borst, H.

    1976-07-01

    In this paper, the properties of gas telescopes with three-piece measuring volume are analyzed. First, the principle of measurement on which gas telescopes are based is explained and ranges of application resulting from it as well as principles of possible realizations are discussed. Then a new theory of proportional gas amplification is derived in its application on methane gas, whose results are used in further descriptions. The following section deals with energy-dependent properties of gas telescopes. Here, it is shown that neutron energies above 100 keV can be measured with gas telescopes. In a further section, the prototype is described and its theoretical properties are shown. Finally, alternative possibilties of design are given from which good properties may be expected, even with accompanying gamma rays. (orig./GSC) [de

  4. Automatic modeling using PENELOPE of two HPGe detectors used for measurement of environmental samples by γ-spectrometry from a few sets of experimental efficiencies

    Science.gov (United States)

    Guerra, J. G.; Rubiano, J. G.; Winter, G.; Guerra, A. G.; Alonso, H.; Arnedo, M. A.; Tejera, A.; Mosqueda, F.; Martel, P.; Bolivar, J. P.

    2018-02-01

    The aim of this paper is to characterize two HPGe gamma-ray detectors used in two different laboratories for environmental radioactivity measurements, so as to perform efficiency calibrations by means of Monte Carlo Simulation. To achieve such an aim, methodologies developed in previous papers have been applied, based on the automatic optimization of the model of detector, so that the differences between computational and reference FEPEs are minimized. In this work, such reference FEPEs have been obtained experimentally from several measurements of the IAEA RGU-1 reference material for specific source-detector arrangements. The models of both detectors built through these methodologies have been validated by comparing with experimental results for several reference materials and different measurement geometries, showing deviations below 10% in most cases.

  5. NDA (Non Destructive Assay) measurements for isotopic homogeneity of UO2 powder form mechanical blending and results comparison between gamma and mass spectrometry

    International Nuclear Information System (INIS)

    Rojas, Carlos A.; Rojo, Marcelo

    2005-01-01

    Eight batches of 0.95% UO2 powder, obtained by mechanical blending of 3.5% and 0.711 % UO2 powders, were sampled. From each batch, samples at the top and the bottom from four drums were taken. Each sample was analysed using different measurement systems, two with NaI(Tl) detectors and another two with HPGe detectors. The Mini Multichannel Analyser (MMCA), model GBS 166, and the calculation codes NaIGEM and MEGAU-EM for peak area analysis and enrichment determination were used. For all cases the WinSPEC acquisition code was used. From the statistical analysis of the measurement results it arises that it is possible to determine the homogeneity grade of UO2 powder samples with a lower error than 0.5% for both types of detectors. The performance of the HPGe measurement system is only slightly more precise than the NaI system. (author)

  6. Statistical methods for mass spectrometry-based clinical proteomics

    NARCIS (Netherlands)

    Kakourou, A.

    2018-01-01

    The work presented in this thesis focuses on methods for the construction of diagnostic rules based on clinical mass spectrometry proteomic data. Mass spectrometry has become one of the key technologies for jointly measuring the expression of thousands of proteins in biological samples.

  7. Atomic Absorption, Atomic Fluorescence, and Flame Emission Spectrometry.

    Science.gov (United States)

    Horlick, Gary

    1984-01-01

    This review is presented in six sections. Sections focus on literature related to: (1) developments in instrumentation, measurement techniques, and procedures; (2) performance studies of flames and electrothermal atomizers; (3) applications of atomic absorption spectrometry; (4) analytical comparisons; (5) atomic fluorescence spectrometry; and (6)…

  8. Measurement of elemental speciation by liquid chromatography -- inductively coupled plasma mass spectrometry (LC-ICP-MS) with the direct injection nebulizer (DIN)

    Energy Technology Data Exchange (ETDEWEB)

    Shum, Sam [Iowa State Univ., Ames, IA (United States)

    1993-05-01

    This thesis is divided into 4 parts: elemental speciation, speciation of mercury and lead compounds by microbore column LC-ICP-MS with direct injection nebulization, spatially resolved measurements of size and velocity distributions of aerosol droplets from a direct injection nebulizer, and elemental speciation by anion exchange and size exclusion chromatography with detection by ICP-MS with direct injection nebulization.

  9. Selective conversion of plasma glucose into CO2 by Saccharomyces cerevisiae for the measurement of C-13 abundance by isotope ratio mass spectrometry : proof of principle

    NARCIS (Netherlands)

    Rembacz, Krzysztof P.; Faber, Klaas Nico; Stellaard, Frans

    2007-01-01

    To study carbohydrate digestion and glucose absorption, time-dependent C-13 enrichment in plasma glucose is measured after oral administration of naturally occurring C-13-enriched carbohydrates. The isotope enrichment of the administered carbohydrate is low (APE <0.1%) and plasma C-13 glucose

  10. Ambient ionization mass spectrometry

    International Nuclear Information System (INIS)

    Lebedev, A T

    2015-01-01

    Ambient ionization mass spectrometry emerged as a new scientific discipline only about ten years ago. A considerable body of information has been reported since that time. Keeping the sensitivity, performance and informativity of classical mass spectrometry methods, the new approach made it possible to eliminate laborious sample preparation procedures and triggered the development of miniaturized instruments to work directly in the field. The review concerns the theoretical foundations and design of ambient ionization methods. Their advantages and drawbacks, as well as prospects for application in chemistry, biology, medicine, environmetal analysis, etc., are discussed. The bibliography includes 194 references

  11. Centralizing and decentralizing the system for unifying measurements on ionizing-radiation characteristics (medium-energy photon and charged-particle radiometry and spectrometry)

    International Nuclear Information System (INIS)

    Bregadze, Yu.I.; Stepanov, E.K.

    1993-01-01

    Ionizing-radiation applications have gradually defined the physical quantities needed to describe radiation sources, radiation as such, and interactions with matter. The optimum unit system has not yet been defined, since new regularities appear during research on the interactions of radiation with matter, and new relationships are being discovered between the radiation characteristics and the observed effects. There are 13 state primary standards in the measurement of ionizing radiation. Several of the standards reproduce the same unit but for different forms of radiation, while special standards reproduce units under special conditions. The present article discusses the various approaches to centralizing and decentralizing systems of supporting unified measurements for various ionizing-radiation characteristics. The three basic physical quantities used to characterize radioactive sources -- radionuclide activity, external particle emission, and particle energy -- are addressed separately. 10 refs

  12. Measurement of low-ppm mixing ratios of water vapor in the upper troposphere and lower stratosphere using chemical ionization mass spectrometry

    Directory of Open Access Journals (Sweden)

    T. D. Thornberry

    2013-06-01

    Full Text Available A chemical ionization mass spectrometer (CIMS instrument has been developed for the fast, precise, and accurate measurement of water vapor (H2O at low mixing ratios in the upper troposphere and lower stratosphere (UT/LS. A low-pressure flow of sample air passes through an ionization volume containing an α-particle radiation source, resulting in a cascade of ion-molecule reactions that produce hydronium ions (H3O+ from ambient H2O. The production of H3O+ ions from ambient H2O depends on pressure and flow through the ion source, which were tightly controlled in order to maintain the measurement sensitivity independent of changes in the airborne sampling environment. The instrument was calibrated every 45 min in flight by introducing a series of H2O mixing ratios between 0.5 and 153 parts per million (ppm, 10−6 mol mol−1 generated by Pt-catalyzed oxidation of H2 standards while overflowing the inlet with dry synthetic air. The CIMS H2O instrument was deployed in an unpressurized payload area aboard the NASA WB-57F high-altitude research aircraft during the Mid-latitude Airborne Cirrus Properties Experiment (MACPEX mission in March and April 2011. The instrument performed successfully during seven flights, measuring H2O mixing ratios below 5 ppm in the lower stratosphere at altitudes up to 17.7 km, and as low as 3.5 ppm near the tropopause. Data were acquired at 10 Hz and reported as 1 s averages. In-flight calibrations demonstrated a typical sensitivity of 2000 Hz ppm−1 at 3 ppm with a signal to noise ratio (2 σ, 1 s greater than 32. The total measurement uncertainty was 9 to 11%, derived from the uncertainty in the in situ calibrations.

  13. Inter-laboratory comparison of elemental analysis and gas chromatography combustion isotope ratio mass spectrometry (GC-C-IRMS). Part I: delta13C measurements of selected compounds for the development of an isotopic Grob-test.

    Science.gov (United States)

    Serra, F; Janeiro, A; Calderone, G; Rojas, J M Moreno; Rhodes, C; Gonthier, L A; Martin, F; Lees, M; Mosandl, A; Sewenig, S; Hener, U; Henriques, B; Ramalho, L; Reniero, F; Teixeira, A J; Guillou, C

    2007-03-01

    This study was directed towards investigating suitable compounds to be used as stable isotope reference materials for gas chromatography combustion isotope ratio mass spectrometry (GC-C-IRMS) calibration. Several compounds were selected from those used in the 'Grob-test' mixture. Oxygen- and nitrogen-containing substances were added to these compounds to allow the mixture to be used as a possible multi-isotopic calibration tool for 2H/1H, 13C/12C, 15N/14N and 18O/16O ratio determinations. In this paper we present the results of delta13C measurements performed by the consortium of the five laboratories taking part in this inter-calibration exercise. All the compounds were individually assessed for homogeneity, short-term stability and long-term stability by means of EA-IRMS, as required by the bureau communitaire de reference (BCR) Guide for Production of Certified Reference Materials. The results were compared then with the GC-C-IRMS measurements using both polar and non-polar columns, and the final mixture of selected compounds underwent a further certification exercise assessing limits of accuracy and reproducibility under specified GC-C-IRMS conditions. Copyright 2007 John Wiley & Sons, Ltd.

  14. Metrological system for y-ray spectrometry measurement of the specific activity and mass fraction of natural radioactive elements in soil and rock samples

    International Nuclear Information System (INIS)

    Khaikovich, I.M.; Fominykh, V.I.; Kirisyuk, E.M.; Belyachkov, Y.A.

    1994-01-01

    In the last few years a great deal of attention has been devoted to the study of the radiation conditions, which in some regions change markedly as a result of intense human activity. One reason for radioactive contamination of an area is dissemination during extraction and processing of radioactive ores or other minerals of natural radioactive elements with a high content of potassium, uranium (radium), and thorium. Estimation of the level of radioactive contamination is one of the main problems of ecological monitoring, and the quality of the measurements sometimes plays a deciding role in the fate of the object being investigated. This also pertains to, in particular, estimation of radioactive contamination of minerals employed for building homes and factories and other industrial structures. In order to draw unequivocal and well-founded conclusions from measurements of the content of natural radioactive elements in soil and rock samples, collected at the object being investigated, a great deal of attention must be devoted during the organization of the measurements to the metrological system

  15. Soil metal concentrations and productivity of Betula populifolia (gray birch) as measured by field spectrometry and incremental annual growth in an abandoned urban Brownfield in New Jersey

    Energy Technology Data Exchange (ETDEWEB)

    Gallagher, Frank J. [Urban Forestry Program, Department of Ecology, Evolution and Natural Resources, Rutgers, State University, 14 College Farm Road, New Brunswick, NJ 08901-8551 (United States); Pechmann, Ildiko [Department of Biological Sciences, Rutgers, State University, 113 University Avenue, Newark, NJ 07102 (United States)], E-mail: pildiko@andromeda.rutgers.edu; Bogden, John D. [Department of Preventive Medicine and Community Health, University of Medicine and Dentistry of New Jersey - N. J. Medical School, P.O. Box 1709, Newark, NJ 07101-1709 (United States); Grabosky, Jason [Urban Forestry Program, Department of Ecology, Evolution and Natural Resources, Rutgers, State University, 14 College Farm Road, New Brunswick, NJ 08901-8551 (United States); Weis, Peddrick [Department of Radiology, University of Medicine and Dentistry of New Jersey - N. J. Medical School, P.O. Box 1709, Newark, NJ 07101-1709 (United States)

    2008-12-15

    A forested brownfield within Liberty State Park, Jersey City, New Jersey, USA, has soils with arsenic, chromium, lead, zinc and vanadium at concentrations above those considered ambient for the area. Using both satellite imagery and field spectral measurements, this study examines plant productivity at the assemblage and individual specimen level. Longer term growth trends (basal area increase in tree cores) were also studied. Leaf chlorophyll content within the hardwood assemblage showed a threshold model for metal tolerance, decreasing significantly beyond a soil total metal load (TML) of 3.0. Biomass production (calculated with RG - Red/Green Ratio Index) in Betula populifolia (gray birch), the co-dominant tree species, had an inverse relationship with the Zn concentration in leaf tissue during the growing season. Growth of B. populifolia exhibited a significant relationship with TML. Assemblage level NDVI and individual tree NDVI also had significant decreases with increasing TML. Ecosystem function measured as plant production is impaired at a critical soil metal load. - Ecosystem function as measured by plant production is impaired at a critical soil metal load (TML above 3) in northern hardwood assemblages growing in a metal-contaminated brownfield.

  16. Quantifying uncertainty in measurement of mercury in suspended particulate matter by cold vapor technique using atomic absorption spectrometry with hydride generator.

    Science.gov (United States)

    Singh, Nahar; Ahuja, Tarushee; Ojha, Vijay Narain; Soni, Daya; Tripathy, S Swarupa; Leito, Ivo

    2013-01-01

    As a result of rapid industrialization several chemical forms of organic and inorganic mercury are constantly introduced to the environment and affect humans and animals directly. All forms of mercury have toxic effects; therefore accurate measurement of mercury is of prime importance especially in suspended particulate matter (SPM) collected through high volume sampler (HVS). In the quantification of mercury in SPM samples several steps are involved from sampling to final result. The quality, reliability and confidence level of the analyzed data depends upon the measurement uncertainty of the whole process. Evaluation of measurement uncertainty of results is one of the requirements of the standard ISO/IEC 17025:2005 (European Standard EN IS/ISO/IEC 17025:2005, issue1:1-28, 2006). In the presented study the uncertainty estimation in mercury determination in suspended particulate matter (SPM) has been carried out using cold vapor Atomic Absorption Spectrometer-Hydride Generator (AAS-HG) technique followed by wet chemical digestion process. For the calculation of uncertainty, we have considered many general potential sources of uncertainty. After the analysis of data of seven diverse sites of Delhi, it has been concluded that the mercury concentration varies from 1.59 ± 0.37 to 14.5 ± 2.9 ng/m(3) with 95% confidence level (k = 2).

  17. Soil metal concentrations and productivity of Betula populifolia (gray birch) as measured by field spectrometry and incremental annual growth in an abandoned urban Brownfield in New Jersey

    International Nuclear Information System (INIS)

    Gallagher, Frank J.; Pechmann, Ildiko; Bogden, John D.; Grabosky, Jason; Weis, Peddrick

    2008-01-01

    A forested brownfield within Liberty State Park, Jersey City, New Jersey, USA, has soils with arsenic, chromium, lead, zinc and vanadium at concentrations above those considered ambient for the area. Using both satellite imagery and field spectral measurements, this study examines plant productivity at the assemblage and individual specimen level. Longer term growth trends (basal area increase in tree cores) were also studied. Leaf chlorophyll content within the hardwood assemblage showed a threshold model for metal tolerance, decreasing significantly beyond a soil total metal load (TML) of 3.0. Biomass production (calculated with RG - Red/Green Ratio Index) in Betula populifolia (gray birch), the co-dominant tree species, had an inverse relationship with the Zn concentration in leaf tissue during the growing season. Growth of B. populifolia exhibited a significant relationship with TML. Assemblage level NDVI and individual tree NDVI also had significant decreases with increasing TML. Ecosystem function measured as plant production is impaired at a critical soil metal load. - Ecosystem function as measured by plant production is impaired at a critical soil metal load (TML above 3) in northern hardwood assemblages growing in a metal-contaminated brownfield

  18. Flux measurement of methanol, acetaldehyde and other oxygenated VOCs from crop harvesting using proton-transfer-reaction mass spectrometry and surface layer gradient method

    International Nuclear Information System (INIS)

    Lindinger, C.; Jordan, A.; Karl, T.; Guenther, A.; Tschiersch, J.; Ruckerbauer, F.; Paretzke, H.

    2002-01-01

    PTR-MS technique was used to measure fluxes of various VOC's including oxygenates using surface layer gradient method. The VOC concentrations and temperature were measured at heights of about 0.5 m and 3.9 m above ground at field site in St. Johann in Tirol during and after grass cutting (24th and 25th of May 2000) in order to calculate fluxes. The sensible heat flux was obtained by a sonic anemometer with turbulence data analyzer. The major crop in this part of Austria are perennial grasses used for livestock farming. We observed VOC emission fluxes including methanol and acetaldehyde as the major volatile, C 5 and C 6 leaf wound compounds with lesser amounts and traces of acetone and butanone. This composition of VOC's is very similar to that released from slashed pasture grass. At the same time, VOC fluxes were measured with PTR-MS and eddy covariance method. Comparing the flux data of methanol and acetaldehyde of both days have shown very similar results. (author)

  19. Quantitative mass spectrometry: an overview

    Science.gov (United States)

    Urban, Pawel L.

    2016-10-01

    Mass spectrometry (MS) is a mainstream chemical analysis technique in the twenty-first century. It has contributed to numerous discoveries in chemistry, physics and biochemistry. Hundreds of research laboratories scattered all over the world use MS every day to investigate fundamental phenomena on the molecular level. MS is also widely used by industry-especially in drug discovery, quality control and food safety protocols. In some cases, mass spectrometers are indispensable and irreplaceable by any other metrological tools. The uniqueness of MS is due to the fact that it enables direct identification of molecules based on the mass-to-charge ratios as well as fragmentation patterns. Thus, for several decades now, MS has been used in qualitative chemical analysis. To address the pressing need for quantitative molecular measurements, a number of laboratories focused on technological and methodological improvements that could render MS a fully quantitative metrological platform. In this theme issue, the experts working for some of those laboratories share their knowledge and enthusiasm about quantitative MS. I hope this theme issue will benefit readers, and foster fundamental and applied research based on quantitative MS measurements. This article is part of the themed issue 'Quantitative mass spectrometry'.

  20. Eddy covariance measurements with high-resolution time-of-flight aerosol mass spectrometry: a new approach to chemically resolved aerosol fluxes

    Directory of Open Access Journals (Sweden)

    D. K. Farmer

    2011-06-01

    Full Text Available Although laboratory studies show that biogenic volatile organic compounds (VOCs yield substantial secondary organic aerosol (SOA, production of biogenic SOA as indicated by upward fluxes has not been conclusively observed over forests. Further, while aerosols are known to deposit to surfaces, few techniques exist to provide chemically-resolved particle deposition fluxes. To better constrain aerosol sources and sinks, we have developed a new technique to directly measure fluxes of chemically-resolved submicron aerosols using the high-resolution time-of-flight aerosol mass spectrometer (HR-AMS in a new, fast eddy covariance mode. This approach takes advantage of the instrument's ability to quantitatively identify both organic and inorganic components, including ammonium, sulphate and nitrate, at a temporal resolution of several Hz. The new approach has been successfully deployed over a temperate ponderosa pine plantation in California during the BEARPEX-2007 campaign, providing both total and chemically resolved non-refractory (NR PM1 fluxes. Average deposition velocities for total NR-PM1 aerosol at noon were 2.05 ± 0.04 mm s−1. Using a high resolution measurement of the NH2+ and NH3+ fragments, we demonstrate the first eddy covariance flux measurements of particulate ammonium, which show a noon-time deposition velocity of 1.9 ± 0.7 mm s−1 and are dominated by deposition of ammonium sulphate.

  1. High-precision measurement of phenylalanine δ15N values for environmental samples: a new approach coupling high-pressure liquid chromatography purification and elemental analyzer isotope ratio mass spectrometry.

    Science.gov (United States)

    Broek, Taylor A B; Walker, Brett D; Andreasen, Dyke H; McCarthy, Matthew D

    2013-11-15

    Compound-specific isotope analysis of individual amino acids (CSI-AA) is a powerful new tool for tracing nitrogen (N) source and transformation in biogeochemical cycles. Specifically, the δ(15)N value of phenylalanine (δ(15)N(Phe)) represents an increasingly used proxy for source δ(15)N signatures, with particular promise for paleoceanographic applications. However, current derivatization/gas chromatography methods require expensive and relatively uncommon instrumentation, and have relatively low precision, making many potential applications impractical. A new offline approach has been developed for high-precision δ(15)N measurements of amino acids (δ(15)N(AA)), optimized for δ(15)N(Phe) values. Amino acids (AAs) are first purified via high-pressure liquid chromatography (HPLC), using a mixed-phase column and automated fraction collection. The δ(15)N values are determined via offline elemental analyzer-isotope ratio mass spectrometry (EA-IRMS). The combined HPLC/EA-IRMS method separated most protein AAs with sufficient resolution to obtain accurate δ(15)N values, despite significant intra-peak isotopic fractionation. For δ(15)N(Phe) values, the precision was ±0.16‰ for standards, 4× better than gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS; ±0.64‰). We also compared a δ(15)N(Phe) paleo-record from a deep-sea bamboo coral from Monterey Bay, CA, USA, using our method versus GC/C/IRMS. The two methods produced equivalent δ(15)N(Phe) values within error; however, the δ(15)N(Phe) values from HPLC/EA-IRMS had approximately twice the precision of GC/C/IRMS (average stdev of 0.27‰ ± 0.14‰ vs 0.60‰ ± 0.20‰, respectively). These results demonstrate that offline HPLC represents a viable alternative to traditional GC/C/IMRS for δ(15)N(AA) measurement. HPLC/EA-IRMS is more precise and widely available, and therefore useful in applications requiring increased precision for data interpretation (e.g. δ(15)N paleoproxies

  2. Neutron spectrometry and dosimetry with ANNs

    International Nuclear Information System (INIS)

    Vega C, H. R.; Hernandez D, V. M.; Gallego, E.; Lorente, A.

    2009-10-01

    Artificial neural networks technology has been applied to unfold the neutron spectra and to calculate the effective dose, the ambient equivalent dose, and the personal dose equivalent for 252 Cf and 241 AmBe neutron sources. A Bonner sphere spectrometry with a 6 LiI(Eu) scintillator was utilized to measure the count rates of the spheres that were utilized as input in two artificial neural networks, one for spectrometry and another for dosimetry. Spectra and the ambient dose equivalent were also obtained with BUNKIUT code and the UTA4 response matrix. With both procedures spectra and ambient dose equivalent agrees in less than 10%. (author)

  3. Feasibility study of calibration strategy for direct quantitative measurement of K and Mg in plant material by laser-induced breakdown spectrometry

    Directory of Open Access Journals (Sweden)

    Daniel Menezes Silvestre

    2015-09-01

    Full Text Available The calibration and quantitative measurement is the “Achilles heel” of the LIBS technique. This paper deals with a method developed for the direct measurement of K and Mg in plant samples. Instrumental parameters were optimized and the best condition found was a 50 μm spot size, 10 Hz laser repetition rate, 75 accumulated laser pulses with 25 mJ/pulse and 0.25 μs of delay time. For method calibration, the use of synthetic standard calibrating material prepared by the addition of increasing concentrations of K and Mg in wood, filter paper and babassu mesocarp was proposed in order to assess the feasibility of using these various matrices in plant samples analysis. The limits of detection of proposed method were 2–30 and 6–27 μg g−1 for K and Mg, respectively. The use of the carbon emission wavelength at 247.856 nm was used as internal standard to improve the analytical results. Certified reference materials of plants were used to check the accuracy of the proposed method and recovery around 82% and 100% were obtained in all cases.

  4. Complementary online aerosol mass spectrometry and offline FT-IR spectroscopy measurements: Prospects and challenges for the analysis of anthropogenic aerosol particle emissions

    Science.gov (United States)

    Faber, Peter; Drewnick, Frank; Bierl, Reinhard; Borrmann, Stephan

    2017-10-01

    The aerosol mass spectrometer (AMS) is well established in investigating highly time-resolved dynamics of submicron aerosol chemical composition including organic aerosol (OA). However, interpretation of mass spectra on molecular level is limited due to strong fragmentation of organic substances and potential reactions inside the AMS ion chamber. Results from complementary filter-based FT-IR absorption measurements were used to explain features in high-resolution AMS mass spectra of different types of OA (e.g. cooking OA, cigarette smoking OA, wood burning OA). Using this approach some AMS fragment ions were validated in this study as appropriate and rather specific markers for a certain class of organic compounds for all particle types under investigation. These markers can therefore be used to get deeper insights in the chemical composition of OA based on AMS mass spectra in upcoming studies. However, the specificity of other fragment ions such as C2H4O2+ (m/z 60.02114) remains ambiguous. In such cases, complementary FT-IR measurements allow the interpretation of highly time-resolved AMS mass spectra at the level of molecular functional groups. Furthermore, this study discusses the challenges in reducing inorganic interferences (e.g. from water and ammonium salts) in FT-IR spectra of atmospheric aerosols to decrease spectral uncertainties for better comparisons and, thus, to get more robust results.

  5. The measurement of urinary 8-hidroxy-2'deoxyguanosine level with liquid chromatography-tandem mass spectrometry method in patients with polycystic ovary syndrome

    Directory of Open Access Journals (Sweden)

    Şeyda Özdemir

    2014-03-01

    Full Text Available Objective: The measurement of urinary 8-hidroxy- 2’deoxyguanosine (8-OHdG level by liquid chromatography-tandem mass (LC-MS/MS method in order to determine whether there is an obvious oxidative deoxyribonucleic acid (DNA damage in patients with Polycystic Ovary Syndrome (PCOS and its relationship with long term risks. Material Methods: Twenty-eight patients with PCOS diagnosis according to the criteria of 2003 Rotterdam Concensus Conference on PCOS were included in this study and twenty-seven healthy women were included as control group. After collecting first morning urine samples of patients and women in control group, the urinary 8-OHdG level were measured by LC-MS/MS method and the results were expressed as nmol/L. 8-OHdG/creatinine ratio (nmol/mol was used to compensate the variation of all nucleoside concentration in urine. The patients with PCOS and the control group were compared in terms of the 8-OHdG/creatinine ratio. Results: Statistically, there was not a significant difference between the patients with PCOS and the control group in terms of the 8-OHdG/creatinine ratio (p= 0.533. Conclusion: According to our research, due to an increase of antioxidant and DNA repair capacity, the urinary 8-OHdG/creatinine ratio as a determinant of oxidative stress in patients with PCOS was not different from the level analyzed in healthy women.

  6. Atomization in graphite-furnace atomic absorption spectrometry. Peak-height method vs. integration method of measuring absorbance: carbon rod atomizer 63

    International Nuclear Information System (INIS)

    Sturgeon, R.E.; Chakrabarti, C.L.; Maines, I.S.; Bertels, P.C.

    1975-01-01

    Oscilloscopic traces of transient atomic absorption signals generated during continuous heating of a Carbon Rod Atomizer model 63 show features which are characteristic of the element being atomized. This research was undertaken to determine the significance and usefulness of the two analytically significant parameters, absorbance maximum and integrated absorbance. For measuring integrated absorbance, an electronic integrating control unit consisting of a timing circuit, a lock-in amplifier, and a digital voltmeter, which functions as a direct absorbance x second readout, has been designed, developed, and successfully tested. Oscilloscopic and recorder traces of the absorbance maximum and digital display of the integrated absorbance are simultaneously obtained. For the elements studied, Cd, Zn, Cu, Al, Sn, Mo, and V, the detection limits and the precision obtained are practically identical for both methods of measurements. The sensitivities by the integration method are about the same as, or less than, those obtained by the peak-height method, whereas the calibration curves by the former are generally linear over wider ranges of concentrations. (U.S.)

  7. Miniaturization and Mass Spectrometry

    NARCIS (Netherlands)

    le Gac, S.; le Gac, Severine; van den Berg, Albert; van den Berg, A.; Unknown, [Unknown

    2009-01-01

    With this book we want to illustrate how two quickly growing fields of instrumentation and technology, both applied to life sciences, mass spectrometry and microfluidics (or microfabrication) naturally came to meet at the end of the last century and how this marriage impacts on several types of

  8. Fourier Transform Mass Spectrometry.

    Science.gov (United States)

    Gross, Michael L.; Rempel, Don L.

    1984-01-01

    Discusses the nature of Fourier transform mass spectrometry and its unique combination of high mass resolution, high upper mass limit, and multichannel advantage. Examines its operation, capabilities and limitations, applications (ion storage, ion manipulation, ion chemistry), and future applications and developments. (JN)

  9. Analytical mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

    This 43rd Annual Summer Symposium on Analytical Chemistry was held July 24--27, 1990 at Oak Ridge, TN and contained sessions on the following topics: Fundamentals of Analytical Mass Spectrometry (MS), MS in the National Laboratories, Lasers and Fourier Transform Methods, Future of MS, New Ionization and LC/MS Methods, and an extra session. (WET)

  10. Analytical mass spectrometry. Abstracts

    Energy Technology Data Exchange (ETDEWEB)

    1990-12-31

    This 43rd Annual Summer Symposium on Analytical Chemistry was held July 24--27, 1990 at Oak Ridge, TN and contained sessions on the following topics: Fundamentals of Analytical Mass Spectrometry (MS), MS in the National Laboratories, Lasers and Fourier Transform Methods, Future of MS, New Ionization and LC/MS Methods, and an extra session. (WET)

  11. High-precision measurement of mercury isotope ratios in sediments using cold-vapor generation multi-collector inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Foucher, Delphine; Hintelmann, Holger

    2006-01-01

    An on-line Hg reduction technique using stannous chloride as the reductant was applied for accurate and precise mercury isotope ratio determinations by multi-collector (MC)-ICP/MS. Special attention has been paid to ensure optimal conditions (such as acquisition time and mercury concentration) allowing precision measurements good enough to be able to significantly detect the anticipated small differences in Hg isotope ratios in nature. Typically, internal precision was better than 0.002% (1 RSE) on all Hg ratios investigated as long as approximately 20 ng of Hg was measured with a 10-min acquisition time. Introducing higher amounts of mercury (50 ng Hg) improved the internal precision to 205 Tl/ 203 Tl correction coupled to a standard-sample bracketing approach. The large number of data acquired allowed us to validate the consistency of our measurements over a one-year period. On average, the short-term uncertainty determined by repeated runs of NIST SRM 1641d Hg standard during a single day was 202 Hg/ 198 Hg, 202 Hg/ 199 Hg, 202 Hg/ 200 Hg, and 202 Hg/ 201 Hg). The precision fell to 202 Hg/ 198 Hg expressed as δ values (per mil deviations relative to NIST SRM 1641d Hg standard solution) displayed differences from +0.74 to -4.00 permille. The magnitude of the Hg fractionation per amu was constant within one type of sample and did not exceed 1.00 permille. Considering all results (the reproducibility of Hg standard solutions, reference sediment samples, and the examination of natural samples), the analytical error of our δ values for the overall method was within ±0.28 permille (1 SD), which was an order of magnitude lower than the extent of fractionation (4.74 permille) observed in sediments. This study confirmed that analytical techniques have reached a level of long-term precision and accuracy that is sufficiently sensitive to detect even small differences in Hg isotope ratios that occur within one type of samples (e.g., between different sediments) and so

  12. Flavor release measurement by atmospheric pressure chemical ionization ion trap mass spectrometry, construction of interface and mathematical modeling of release profiles

    DEFF Research Database (Denmark)

    Haahr, Anne-Mette; Madsen, Henrik; Smedsgaard, Jørn

    2003-01-01

    and the method can be used to measure breath from the nose. A mathematical model of the data was developed to give a quantitative method for description and characterization of the release of flavor compounds. The release profiles consisted of two sequences, one for a chewing period, and one for a phasing out...... process. The proposed method for modeling provided a reasonable description of the release process. In addition to flavor compounds, this new interface and mathematical application could provide information on chemicals in the human breath which could be interesting, for example, within medical diagnosis....... with that of the flavor detection threshold. An application study on the release of menthone and menthol from chewing gum by a group of six test persons was performed. Flavored chewing gum was used as a model matrix because of the long chewing periods and the simplicity of the system. It is concluded that the interface...

  13. Determination of ultra-low level 129I in vegetation using pyrolysis for iodine separation and accelerator mass spectrometry measurements

    DEFF Research Database (Denmark)

    Hou, Xiaolin; Wang, Yanyun

    2016-01-01

    Radioactive isotopes of iodine are the most common radiological toxins from nuclear accidents due to their high release and high enrichment in human thyroid. Among the radioactive isotopes, long-lived 129I can not only be used for the estimation of the radioactive risk of short-lived radioactive...... and ultra-low concentration in normal environmental and biological samples, it is important to efficiently separate iodine from the sample matrix and sensitively measure 129I. However, the complicated chemical properties of iodine and high organic content in biological samples make efficient separation...... of iodine very difficult using conventional acid digestion and alkaline ashing methods. By optimizing the key parameters related to the separation of iodine by pyrolysis using a tube furnace, including carbonization temperature, heating protocol, combustion assisting gas, iodine volatilization process...

  14. Measurements of HNO3 and N2O5 using ion drift-chemical ionization mass spectrometry during the MILAGRO/MCMA-2006 campaign

    Science.gov (United States)

    Zheng, J.; Zhang, R.; Fortner, E. C.; Volkamer, R. M.; Molina, L.; Aiken, A. C.; Jimenez, J. L.; Gaeggeler, K.; Dommen, J.; Dusanter, S.; Stevens, P. S.; Tie, X.

    2008-11-01

    An ion drift-chemical ionization mass spectrometer (ID-CIMS) was deployed in Mexico City between 7 and 31 March to measure gas-phase nitric acid (HNO3) and dinitrogen pentoxide (N2O5 during the Mexico City Metropolitan Area (MCMA)-2006 field campaign. The observation site was located at the Instituto Mexicano del Petróleo in the northern part of Mexico City urban area with major emissions of pollutants from residential, vehicular and industrial sources. Diurnally, HNO3 was less than 200 parts per trillion (ppt) during the night and early morning. The concentration of HNO3 increased steadily from around 09:00 a.m. central standard time (CST), reached a peak value of 0.5 to 3 parts per billion (ppb) in the early afternoon, and then declined sharply to less than half of the peak value near 05:00 p.m. CST. An inter-comparison between the ID-CIMS and an ion chromatograph/mass spectrometer (ICMS) showed a good agreement between the two HNO3 measurements (R2=0.75). The HNO3 mixing ratio was found to anti-correlate with submicron-sized aerosol nitrate, suggesting that the gas-particle partitioning process was a major factor in determining the gaseous HNO3 concentration. Losses by irreversible reactions with mineral dust and via dry deposition also could be important at this site. Most of the times during the MCMA 2006 field campaign, N2O5 was found to be below the detection limit (about 30 ppt for a 10 s integration time) of the ID-CIMS, because of high NO mixing ratio at the surface (>100 ppb) during the night. An exception occurred on 26 March 2006, when about 40 ppt N2O5 was observed during the late afternoon and early evening hours under cloudy conditions before the build-up of NO at the surface site. The results revealed that during the MCMA-2006 field campaign HNO3 was primarily produced from the reaction of OH with NO2 and regulated by gas/particle transfer and dry deposition. The production of HNO3 from N2O5 hydrolysis during the nighttime was small because of

  15. Accelerator mass spectrometry in NIPNE

    International Nuclear Information System (INIS)

    Ivascu, M; Marinescu, L.; Dima, R.; Cata-Danil, D.; Petrascu, M.; Popescu, I.; Stan-Sion, C.; Radulescu, M.; Plostinaru, D.

    1997-01-01

    The Accelerator Mass Spectrometry (AMS) is today the method capable to measure the lowest concentration of a particular nuclide in sample materials. The method has applications in environmental physics, medicine, measurements of cosmic-ray or nuclear power plant produced radionuclides in the earth's atmosphere. All over the world, more than 40 charged particles and heavy ion accelerators are performing such analyses concerning the research interest of a huge number of laboratories. The Romanian Institute of Nuclear Physics and Engineering in Bucharest has initiated a construction project for the AMS facility at the FN - Van de Graaff Tandem accelerator. This program benefits of technical and financial assistance provided by IAEA in the frame of the IAEA-TC Project ROM 8014-265C. A general lay-out of the AMS project is presented. The construction work has begun and first tests of the AMS injector will take place between July - September this year. (authors)

  16. Quantification of trace arsenic in soils by field-portable X-ray fluorescence spectrometry: considerations for sample preparation and measurement conditions.

    Science.gov (United States)

    Parsons, Chris; Margui Grabulosa, Eva; Pili, Eric; Floor, Geerke H; Roman-Ross, Gabriela; Charlet, Laurent

    2013-11-15

    Recent technological improvements have led to the widespread adoption of field portable energy dispersive X-ray fluorescence (FP-XRF) by governmental agencies, environmental consultancies and research institutions. FP-XRF units often include analysis modes specifically designed for the quantification of trace elements in soils. Using these modes, X-ray tube based FP-XRF units can offer almost "point and shoot" ease of use and results comparable to those of laboratory based instruments. Nevertheless, FP-XRF analysis is sensitive to spectral interferences as well as physical and chemical matrix effects which can result in decreased precision and accuracy. In this study, an X-ray tube-based FP-XRF analyser was used to determine trace (low ppm) concentrations of As in a floodplain soil. The effect of different sample preparation and analysis conditions on precision and accuracy were systematically evaluated. We propose strategies to minimise sources of error and maximise data precision and accuracy, achieving in situ limits of detection and precision of 6.8 ppm and 14.4%RSD, respectively for arsenic. We demonstrate that soil moisture, even in relatively dry soils, dramatically affects analytical performance with a signal loss of 37% recorded for arsenic at 20 wt% soil moisture relative to dry soil. We also highlight the importance of the use of certified reference materials and independent measurement methods to ensure accurate correction of field values. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Precision of glucose measurements in control sera by isotope dilution/mass spectrometry: proposed definitive method compared with a reference method

    International Nuclear Information System (INIS)

    Pelletier, O.; Arratoon, C.

    1987-01-01

    This improved isotope-dilution gas chromatographic/mass spectrometric (GC/MS) method, in which [ 13 C]glucose is the internal standard, meets the requirements of a Definitive Method. In a first study with five reconstituted lyophilized sera, a nested analysis of variance of GC/MS values indicated considerable among-vial variation. The CV for 32 measurements per serum ranged from 0.5 to 0.9%. However, concentration and uncertainty values (mmol/L per gram of serum) assigned to one serum by the NBS Definitive Method (7.56 +/- 0.28) were practically identical to those obtained with the proposed method (7.57 +/- 0.20). In the second study, we used twice more [ 13 C]glucose diluent to assay four serum pools and two lyophilized sera. The CV ranged from 0.26 to 0.5% for the serum pools and from 0.28 to 0.59% for the lyophilized sera. In comparison, results by the hexokinase/glucose-6-phosphate dehydrogenase reference method agreed within acceptable limits with those by the Definitive Method but tended to be slightly higher (up to 3%) for lyophilized serum samples or slightly lower (up to 2.5%) for serum pools

  18. Accurate argon cluster-ion sputter yields: Measured yields and effect of the sputter threshold in practical depth-profiling by x-ray photoelectron spectroscopy and secondary ion mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Cumpson, Peter J.; Portoles, Jose F.; Barlow, Anders J.; Sano, Naoko [National EPSRC XPS User' s Service (NEXUS), School of Mechanical and Systems Engineering, Newcastle University, Newcastle upon Tyne, NE1 7RU (United Kingdom)

    2013-09-28

    Argon Gas Cluster-Ion Beam sources are likely to become widely used on x-ray photoelectron spectroscopy and secondary ion mass spectrometry instruments in the next few years. At typical energies used for sputter depth profiling the average argon atom in the cluster has a kinetic energy comparable with the sputter threshold, meaning that for the first time in practical surface analysis a quantitative model of sputter yields near threshold is needed. We develop a simple equation based on a very simple model. Though greatly simplified it is likely to have realistic limiting behaviour and can be made useful for estimating sputter yields by fitting its three parameters to experimental data. We measure argon cluster-ion sputter yield using a quartz crystal microbalance close to the sputter threshold, for silicon dioxide, poly(methyl methacrylate), and polystyrene and (along with data for gold from the existing literature) perform least-squares fits of our new sputter yield equation to this data. The equation performs well, with smaller residuals than for earlier empirical models, but more importantly it is very easy to use in the design and quantification of sputter depth-profiling experiments.

  19. Study and validity of 13C stable carbon isotopic ratio analysis by mass spectrometry and 2H site-specific natural isotopic fractionation by nuclear magnetic resonance isotopic measurements to characterize and control the authenticity of honey

    International Nuclear Information System (INIS)

    Cotte, J.F.; Casabianca, H.; Lheritier, J.; Perrucchietti, C.; Sanglar, C.; Waton, H.; Grenier-Loustalot, M.F.

    2007-01-01

    Honey samples were analyzed by stable carbon isotopic ratio analysis by mass spectrometry (SCIRA-MS) and site-specific natural isotopic fractionation measured by nuclear magnetic resonance (SNIF-NMR) to first determine their potentials for characterizing the substance and then to combat adulteration. Honey samples from several geographic and botanical origins were analyzed. The δ 13 C parameter was not significant for characterizing an origin, while the (D/H) I ratio could be used to differentiate certain single-flower varieties. Application of the official control method of adding a C 4 syrup (AOAC official method 998.12) to our authentic samples revealed anomalies resulting from SCIRA indices that were more negative than -1 per mille (permil). A filtration step was added to the experimental procedure and provided results that were compliant with Natural origin of our honey samples. In addition, spiking with a C 4 syrup could be detected starting at 9-10%. The use of SNIF-NMR is limited by the detection of a syrup spike starting only at 20%, which is far from satisfying

  20. Data Generated by Quantitative Liquid Chromatography-Mass Spectrometry Proteomics Are Only the Start and Not the Endpoint: Optimization of Quantitative Concatemer-Based Measurement of Hepatic Uridine-5'-Diphosphate-Glucuronosyltransferase Enzymes with Reference to Catalytic Activity.

    Science.gov (United States)

    Achour, Brahim; Dantonio, Alyssa; Niosi, Mark; Novak, Jonathan J; Al-Majdoub, Zubida M; Goosen, Theunis C; Rostami-Hodjegan, Amin; Barber, Jill

    2018-06-01

    Quantitative proteomic methods require optimization at several stages, including sample preparation, liquid chromatography-tandem mass spectrometry (LC-MS/MS), and data analysis, with the final analysis stage being less widely appreciated by end-users. Previously reported measurement of eight uridine-5'-diphospho-glucuronosyltransferases (UGT) generated by two laboratories [using stable isotope-labeled (SIL) peptides or quantitative concatemer (QconCAT)] reflected significant disparity between proteomic methods. Initial analysis of QconCAT data showed lack of correlation with catalytic activity for several UGTs (1A4, 1A6, 1A9, 2B15) and moderate correlations for UGTs 1A1, 1A3, and 2B7 ( R s = 0.40-0.79, P data analysis, starting from unprocessed LC-MS/MS data, was undertaken, with the aim of improving accuracy, defined by correlation against activity. Three main criteria were found to be important: choice of monitored peptides and fragments, correction for isotope-label incorporation, and abundance normalization using fractional protein mass. Upon optimization, abundance-activity correlations improved significantly for six UGTs ( R s = 0.53-0.87, P data analysis strategy and indicates, using examples, the significance of systematic data processing following acquisition. The proposed strategy offers significant improvement on existing guidelines applicable to clinically relevant proteins quantified using QconCAT. Copyright © 2018 by The American Society for Pharmacology and Experimental Therapeutics.

  1. Measurement and Analysis of Specific Activities of Natural Radionuclides (40K, 226Ra and 232Th) in Beach Sand Samples from Talo Kapo Beach of Yaring District in Pattani Province using Gamma Ray Spectrometry

    Science.gov (United States)

    Daoh, M.; Masae, R. N.; Po-oh, S.; Boonkrongcheep; Kessaratikoon, P.

    2017-09-01

    The Specific Activities of 40K, 226Ra and 232Th were studied and determinate for 30 beach sand samples collected from Talo Kapo beach of Yaring district in Pattani province. Experimental results were obtained by using a high-purity germanium (HPGe) detector and gamma spectrometry analysis system. The IAEA-SOIL-6 reference materials obtained from the International Atomic Energy Agency were also used to analyze and compute the 40K, 226Ra and 232Th specific activity in all 30 beach sand samples. The measuring time of each sample is 10,000 seconds. It was found that specific activity range from 1805.37 - 3323.05, 40.96 - 2137.36 38.63 - 4329.28 Bq/kg for with mean values of 2242.79 ± 117.40, 250.18 ± 8.21 and 458.42 ± 7.68 Bq/kg for 40K, 226Ra and 232Th, respectively. Moreover, the results wer