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Sample records for high-resolution gamma spectrometry

  1. Laboratory of High resolution gamma spectrometry

    International Nuclear Information System (INIS)

    Mendez G, A.; Giber F, J.; Rivas C, I.; Reyes A, B.

    1992-01-01

    The Department of Nuclear Experimentation of the Nuclear Systems Management requests the collaboration of the Engineering unit for the supervision of the execution of the work of the High resolution Gamma spectrometry and low bottom laboratory, using the hut of the sub critic reactor of the Nuclear Center of Mexico. This laboratory has the purpose of determining the activity of special materials irradiated in nuclear power plants. In this report the architecture development, concepts, materials and diagrams for the realization of this type of work are presented. (Author)

  2. Laboratory of High resolution gamma spectrometry; Laboratorio de espectrometria gamma de alta resolucion

    Energy Technology Data Exchange (ETDEWEB)

    Mendez G, A.; Giber F, J.; Rivas C, I.; Reyes A, B

    1992-01-15

    The Department of Nuclear Experimentation of the Nuclear Systems Management requests the collaboration of the Engineering unit for the supervision of the execution of the work of the High resolution Gamma spectrometry and low bottom laboratory, using the hut of the sub critic reactor of the Nuclear Center of Mexico. This laboratory has the purpose of determining the activity of special materials irradiated in nuclear power plants. In this report the architecture development, concepts, materials and diagrams for the realization of this type of work are presented. (Author)

  3. Performance characteristics of high resolution semiconductor gamma ray spectrometry system

    Energy Technology Data Exchange (ETDEWEB)

    Naing, Ko Ko

    1994-05-01

    A high purity germanium (HPGe) gamma-ray detector has been used in Nuclear Research Laboratory, Department of Physics, Yangon University for over fourteen years. Now it is still being used and it is coupled to new peripheral devices, such as spectroscopy amplifier, analog to digital converter and computer fit-in S-100 multichannel analyser. Therefore, it is necessary to determine the important parameters: energy resolution, detecting efficiency and relative efficiency of the system. In the present work, these parameters were obtained by using mixed calibrated source. The results were compared to the data given by the manufacturer. Moreover, the parameters of another {gamma}-ray detecting system NaI(T1) were also determined. In conclusion the results obtained from the above two measurements were compared and discussed

  4. Performance characteristics of high resolution semiconductor gamma ray spectrometry system

    International Nuclear Information System (INIS)

    Ko Ko Naing

    1994-05-01

    A high purity germanium (HPGe) gamma-ray detector has been used in Nuclear Research Laboratory, Department of Physics, Yangon University for over fourteen years. Now it is still being used and it is coupled to new peripheral devices, such as spectroscopy amplifier, analog to digital converter and computer fit-in S-100 multichannel analyser. Therefore, it is necessary to determine the important parameters: energy resolution, detecting efficiency and relative efficiency of the system. In the present work, these parameters were obtained by using mixed calibrated source. The results were compared to the data given by the manufacturer. Moreover, the parameters of another γ-ray detecting system NaI(T1) were also determined. In conclusion the results obtained from the above two measurements were compared and discussed

  5. The application of computer technique in routine neutron activation analysis using high resolution gamma ray spectrometry

    International Nuclear Information System (INIS)

    Szopa, Z.; Plejewska, M.; Staszelis, J.

    1982-01-01

    A full system of four computer programs for routine - qualitative and quantitative - neutron activation analysis (NAA) using high resolution gamma ray-spectrometry had been elaborated. The structure and possibilities of the ''data flow'' programs i.e. programs DIDPDP and DIDCDC, dedicated for fast and reliable ''off line'' data transfer between the buffer memory of the spectrometric line (9-track magnetic tape) and the fast access memory (disc) of the used computers PDP-11/45 and CYBER-73 had been presented. The structure and organization of the ''data processing'' programs i.e. programs SAWAPS and MAZYG had been presented as well. The utility and reliability of these programs in the case of the large-scale, routine NAA, exampled by analysis of filters with air polutants, had been tested and discussed. Programs are written mainly in FORTRAN. (author)

  6. Determination of Pu isotopic composition and 241Am by high resolution gamma spectrometry on solid samples

    International Nuclear Information System (INIS)

    Sarkar, Arnab; Paul, Sumana; Aggarwal, Suresh K.; Tomar, Bhupendra S.

    2011-08-01

    The present report gives a detailed account of the development of non-destructive assay technique using high resolution gamma-ray spectrometry (HRGS) for determination of plutonium (Pu) isotopic composition and the 241 Am content in solid Pu samples. Energy range 120-420 keV was used in this study. The methodology involves in situ relative efficiency calibration during the measurement process itself, to reduce the errors and increase the reliability of the method. Twenty solid Pu samples of power reactor and research reactor grade were analyzed by this method and the results were compared with those obtained by thermal ionization mass spectrometry. The accuracy of the final results depends strongly upon the accuracy of the available nuclear data (decay constant, gamma abundance etc.). MATLAB based programme was written to perform the analysis. A counting time of 4 hour was chosen for achieving good statistics on the results for samples having 100-200 mg of Pu. The attainable accuracy is found to be 0.5-1% for the fissile isotopes ( 239 Pu + 241 Pu) and 5-10% for 241 Am content. (author)

  7. High resolution gamma-ray spectrometry of culverts containing transuranic waste at the Savannah River Site

    International Nuclear Information System (INIS)

    Hofstetter, K.J.; Sigg, R.

    1990-01-01

    A number of concrete culverts used to retrievably store drummed, dry, radioactive waste at the Savannah River Site (SRS), were suspected of containing ambiguous quantities of transuranic (TRU) nuclides. These culverts were assayed in place for Pu-239 content using thermal and fast neutron counting techniques. High resolution gamma-ray spectroscopy on 17 culverts, having neutron emission rates several times higher than expected, showed characteristic gamma-ray signatures of neutron emitters other than Pu-239 (e.g., Pu-238, Pu/Be, or Am/Be neutron sources). This study confirmed the Pu-239 content of the culverts with anomalous neutron rates and established limits on the Pu-239 mass in each of the 17 suspect culverts by in-field, non-intrusive gamma-ray measurements

  8. Standard guide for high-resolution gamma-ray spectrometry of soil samples

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2004-01-01

    1.1 This guide covers the identification and quantitative determination of gamma-ray emitting radionuclides in soil samples by means of gamma-ray spectrometry. It is applicable to nuclides emitting gamma rays with an approximate energy range of 20 to 2000 keV. For typical gamma-ray spectrometry systems and sample types, activity levels of about 5 Bq (135 pCi) are measured easily for most nuclides, and activity levels as low as 0.1 Bq (2.7 pCi) can be measured for many nuclides. It is not applicable to radionuclides that emit no gamma rays such as the pure beta-emitting radionuclides hydrogen-3, carbon-14, strontium-90, and becquerel quantities of most transuranics. This guide does not address the in situ measurement techniques, where soil is analyzed in place without sampling. Guidance for in situ techniques can be found in Ref (1) and (2). This guide also does not discuss methods for determining lower limits of detection. Such discussions can be found in Refs (3), (4), (5), and (6). 1.2 This guide can be us...

  9. Burn-Up Determination by High Resolution Gamma Spectrometry: Fission Product Migration Studies

    Energy Technology Data Exchange (ETDEWEB)

    Forsyth, R S; Blackadder, W H; Ronqvist, N

    1967-04-15

    The migration of solid fission products, in particular caesium and ruthenium, in high temperature oxide fuel can create a severe problem during the application of non-destructive burn-up methods employing gamma spectrometry, since caesium-137 is otherwise the most convenient long-lived burn-up monitor and ruthenium-106 can be used to distinguish between fissions in U-235 and Pu-239. As part of an experimental programme to develop burn-up methods, gamma scanning experiments have been performed on slices of irradiated UO{sub 2} pellets using a lithium-drifted germanium detector. The usefulness of the technique for migration studies has been demonstrated by comparing the fission product distribution curves across the specimen diameters with the microstructure of the specimens after polishing and etching.

  10. Use of a Shielded High Resolution Gamma Spectrometry System to Segregate LLW from Contact Handleable ILW Containing Plutonium - 13046

    Energy Technology Data Exchange (ETDEWEB)

    Lester, Rosemary; Wilkins, Colin [Canberra UK Ltd, Unit 1 B528.1, Harwell Science Campus, Oxfordshire OX11 0DF (United Kingdom); Chard, Patrick [Canberra UK Ltd, Forss Business and Technology park, Thurso, Caithness KW14 7UZ (United Kingdom); Jaederstroem, Henrik; LeBlanc, Paul; Mowry, Rick [Canberra Industries, Inc., 800 Research Parkway, Meriden, Connecticut, 06450 (United States); MacDonald, Sanders; Gunn, William [Dounreay Site Restoration Limited, Dounreay, Thurso, Caithness, KW14 7TZ (United Kingdom)

    2013-07-01

    Dounreay Site Restoration Limited (DSRL) have a number of drums of solid waste that may contain Plutonium Contaminated Material. These are currently categorised as Contact Handleable Intermediate Level Waste (CHILW). A significant fraction of these drums potentially contain waste that is in the Low Level Waste (LLW) category. A Canberra Q2 shielded high resolution gamma spectrometry system is being used to quantify the total activity of drums that are potentially in the LLW category in order to segregate those that do contain LLW from CHILW drums and thus to minimise the total volume of waste in the higher category. Am-241 is being used as an indicator of the presence of plutonium in the waste from its strong 59.54 keV gamma-ray; a knowledge of the different waste streams from which the material originates allows a pessimistic waste 'fingerprint' to be used in order to determine an upper limit to the activities of the weak and non-gamma-emitting plutonium and associated radionuclides. This paper describes the main features of the high resolution gamma spectrometry system being used by DSRL to perform the segregation of CHILW and LLW and how it was configured and calibrated using the Canberra In-Situ Object Counting System (ISOCS). It also describes how potential LLW drums are selected for assay and how the system uses the existing waste stream fingerprint information to determine a reliable upper limit for the total activity present in each measured drum. Results from the initial on-site commissioning trials and the first measurements of waste drums using the new monitor are presented. (authors)

  11. Cooperation on Improved Isotopic Identification and Analysis Software for Portable, Electrically Cooled High-Resolution Gamma Spectrometry Systems Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Dreyer, Jonathan G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Wang, Tzu-Fang [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Vo, Duc T. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Funk, Pierre F. [Inst. for Radiological Protection and Nuclear Safety (IRSN), Fontenay-aux-Roses (France); Weber, Anne-Laure [Inst. for Radiological Protection and Nuclear Safety (IRSN), Fontenay-aux-Roses (France)

    2017-07-20

    Under a 2006 agreement between the Department of Energy (DOE) of the United States of America and the Institut de Radioprotection et de Sûreté Nucléaire (IRSN) of France, the National Nuclear Security Administration (NNSA) within DOE and IRSN initiated a collaboration to improve isotopic identification and analysis of nuclear material [i.e., plutonium (Pu) and uranium (U)]. The specific aim of the collaborative project was to develop new versions of two types of isotopic identification and analysis software: (1) the fixed-energy response-function analysis for multiple energies (FRAM) codes and (2) multi-group analysis (MGA) codes. The project is entitled Action Sheet 4 – Cooperation on Improved Isotopic Identification and Analysis Software for Portable, Electrically Cooled, High-Resolution Gamma Spectrometry Systems (Action Sheet 4). FRAM and MGA/U235HI are software codes used to analyze isotopic ratios of U and Pu. FRAM is an application that uses parameter sets for the analysis of U or Pu. MGA and U235HI are two separate applications that analyze Pu or U, respectively. They have traditionally been used by safeguards practitioners to analyze gamma spectra acquired with high-resolution gamma spectrometry (HRGS) systems that are cooled by liquid nitrogen. However, it was discovered that these analysis programs were not as accurate when used on spectra acquired with a newer generation of more portable, electrically cooled HRGS (ECHRGS) systems. In response to this need, DOE/NNSA and IRSN collaborated to update the FRAM and U235HI codes to improve their performance with newer ECHRGS systems. Lawrence Livermore National Laboratory (LLNL) and Los Alamos National Laboratory (LANL) performed this work for DOE/NNSA.

  12. Burn-Up Determination by High Resolution Gamma Spectrometry: Axial and Diametral Scanning Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Forsyth, R S; Blackadder, W H; Ronqvist, N

    1967-02-15

    In the gamma spectrometric determination of burn-up the use of a single fission product as a monitor of the specimen fission rate is subject to errors caused by activity saturation or, in certain cases, fission product migration. Results are presented of experiments in which all the resolvable gamma peaks in the fission product spectrum have been used to calculate the fission rate; these results form a pattern which reflect errors in the literature values of the gamma branching ratios, fission yields etc., and also represent a series of empirical correction factors. Axial and diametral scanning experiments on a long-irradiated low-enrichment fuel element are also described and demonstrate that it is possible to differentiate between fissions in U-235 and in Pu-239 respectively by means of the ratios of the Ru-106 activity to the activities of the other fission products.

  13. Preliminary Determination of Natural Radioactivity Levels of the State of Qatar using High-Resolution Gamma-ray Spectrometry

    International Nuclear Information System (INIS)

    Al-Sulaiti, H.A.; Regan, P.H.; Bradley, D.A.; Matthews, M.; Santawamaitre, T.; Malain, D.

    2009-01-01

    The State of Qatar is a peninsula with a total area of 11,437 km 2 which lies over a geological formation comprising a sequence of limestone, chalk, clay and gypsum. Establishing a baseline for the radioactivity concentration in Qatar's soil is the main purpose behind the present study. The project is focused on obtaining measurements of representative soil samples from various areas in Qatar to establish concentrations of the 235 U, 238 U and 232 Th natural decay chains and also the long-lived naturally occurring radionuclide 40 K. The 235 U, 238 U, 232 Th and 40 K concentrations have been measured via high-resolution gamma-ray spectrometry using a hyper-pure germanium detector situated in a low-background environment with a copper inner-plated passive lead shield. A wide range of different gamma-ray energy transitions lines arising from the multiple decay products from the 235 U, 238 U and 232 Th decay chains have been analyzed separately to obtain more statistically significant overall results

  14. Rapid non-destructive quantitative estimation of urania/ thoria in mixed thorium uranium di-oxide pellets by high-resolution gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Shriwastwa, B.B.; Kumar, Anil; Raghunath, B.; Nair, M.R.; Abani, M.C.; Ramachandran, R.; Majumdar, S.; Ghosh, J.K.

    2001-01-01

    A non-destructive technique using high-resolution gamma-ray spectrometry has been standardised for quantitative estimation of uranium/thorium in mixed (ThO 2 -UO 2 ) fuel pellets of varying composition. Four gamma energies were selected; two each from the uranium and thorium series and the time of counting has been optimised. This technique can be used for rapid estimation of U/Th percentage in a large number of mixed fuel pellets from a production campaign

  15. Advanced Collimators for Verification of the Pu Isotopic Composition in Fresh Fuel by High Resolution Gamma Spectrometry

    International Nuclear Information System (INIS)

    Lebrun, Alain; Berlizov, Andriy

    2013-06-01

    IAEA verification of the nuclear material contained in fresh nuclear fuel assemblies is usually based on neutron coincidence counting (NCC). In the case of uranium fuel, active NCC provides the total content of uranium-235 per unit of length which, combined with active length verification, fully supports the verification. In the case of plutonium fuel, passive NCC provides the plutonium-240 equivalent content which needs to be associated with a measurement of the isotopic composition and active length measurement to complete the verification. Plutonium isotopic composition is verified by high resolution gamma spectrometry (HRGS) applied on fresh fuel assemblies assuming all fuel rods are fabricated from the same plutonium batch. For particular verifications when such an assumption cannot be reasonably made, there is a need to optimize the HRGS measurement so that contributions of internal rods to the recorded spectrum are maximized, thus providing equally strong verification of the internal fuel rods. This paper reports on simulation work carried out to design special collimators aimed at reducing the relative contribution of external fuel rods while enhancing the signal recorded from internal rods. Both cases of square lattices (e.g. 17x17 pressurized water reactor (PWR) fuel) and hexagonal compact lattices (e.g. BN800 fast neutron reactor (FNR) fuel) have been addressed. In the case of PWR lattices, the relatively large optical path to internal pins compensates for low plutonium concentrations and the large size of the fuel assemblies. A special collimator based on multiple, asymmetrical, vertical slots allows recording a spectrum from internal rods only when needed. In the FNR case, the triangular lattice is much more compact and the optical path to internal rods is very narrow. However, higher plutonium concentration and use of high energy ranges allow the verification of internal rods to be significantly strengthened. Encouraging results from the simulation

  16. Determination of 137Cs activity in soil from Qatar using high-resolution gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Al-Sulaiti, Huda; Nasir, Tabassum; Al Mugren, K.S.; Alkhomashi, N.; Al-Dahan, N.; Al-Dosari, M.; Bradley, D.A.; Bukhari, S.; Matthews, M.; Regan, P.H.; Santawamaitre, T.; Malain, D.; Habib, A.; Al-Dosari, Hanan; Al Sadig, Ibrahim

    2016-01-01

    With interest in establishing baseline concentrations of 137 Cs in soil from the Qatarian peninsula, we focus on determination of the activity concentrations in 129 soil samples collected across the State of Qatar prior to the 2011 Fukushima Dai-ichi nuclear power plant accident. As such, the data provides the basis of a reference map for the detection of releases of this fission product. The activity concentrations were measured via high-resolution gamma-ray spectrometry using a hyper-pure germanium detector enclosed in a copper-lined passive lead shield that was situated in a low-background environment. The activity concentrations ranged from 0.21 to 15.41 Bq/kg, with a median value of 1 Bq/kg, the greatest activity concentration being observed in a sample obtained from northern Qatar. Although it cannot be confirmed, it is expected that this contamination is mainly due to releases from the Chernobyl accident of 26 April 1986, there being a lack of data from Qatar before the accident. The values are typically within but are sometimes lower than the range indicated by data from other countries in the region. The lower values than those of others is suggested to be due to variation in soil characteristics as well as metrological factors at the time of deposition. - Highlights: • A baseline for the radionuclide 137 Cs in soil samples collected from Qatar was established. • 129 soil samples collected across the landscape. • Samples were collected before the most recent accident “the 2011 Fukushima Dai-ichi NNP accident”. • The highest activity concentration was found to be 15.41±0.67 Stat. and 0.11 Syst. • The relatively high concentrations can be attributed to rain washout.

  17. 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)

  18. Rapid non-destructive quantitative estimation of urania/ thoria in mixed thorium uranium di-oxide pellets by high-resolution gamma-ray spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Shriwastwa, B.B.; Kumar, Anil; Raghunath, B.; Nair, M.R.; Abani, M.C.; Ramachandran, R.; Majumdar, S.; Ghosh, J.K

    2001-06-01

    A non-destructive technique using high-resolution gamma-ray spectrometry has been standardised for quantitative estimation of uranium/thorium in mixed (ThO{sub 2}-UO{sub 2}) fuel pellets of varying composition. Four gamma energies were selected; two each from the uranium and thorium series and the time of counting has been optimised. This technique can be used for rapid estimation of U/Th percentage in a large number of mixed fuel pellets from a production campaign.

  19. 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

  20. Comparison of laser fluorimetry, high resolution gamma-ray spectrometry and neutron activation analysis techniques for determination of uranium content in soil samples

    International Nuclear Information System (INIS)

    Ghods, A.; Asgharizadeh, F.; Salimi, B.; Abbasi, A.

    2004-01-01

    Much more concern is given nowadays for exposure of the world population to natural radiation especially to uranium since 57% of that exposure is due to radon-222, which is a member of uranium decay series. Most of the methods used for uranium determination is low concentration require either tedious separation and preconcentration or the accessibility to special instrumentation for detection of uranium at this low level. this study compares three techniques and methods for uranium analysis among different soil sample with variable uranium contents. Two of these techniques, neutron activation analysis and high resolution gamma-ray spectrometry , are non-destructive while the other, laser fluorimetry is done via chemical extraction of uranium. Analysis of standard materials is done also to control the quality and accuracy of the work. In spite of having quite variable ranges of detection limit, results obtained by high resolution gamma-ray spectrometry based on the assumption of having secular equilibrium between uranium and its daughters, which causes deviation whenever this condition was missed. For samples with reasonable uranium content, neutron activation analysis would be a rapid and reliable technique, while for low uranium content laser fluorimetry would be the most appropriate and accurate technique

  1. Evaluation of natural and anthropogenic radioactivity in environmental samples from Kuwait using high-resolution gamma-ray spectrometry

    Science.gov (United States)

    Bajoga, Abubakar D.

    A study of natural radioactivity from ninety different soil samples across the state of Kuwait was carried out with a view to ascertain the level of natural and/or man-made radioactivity from that area. There has been some concern on the levels of NORM following the First Gulf War in which approximately 300 tons of depleted uranium shells were used and in particular, whether it has a significant impact in the surrounding environment. This study uses gamma-spectroscopy in a low background measuring system employing a high resolution Hyper-Pure Germanium detector. The calculated specific activity concentrations are determined for the radionuclides 226Ra, 214Pb, 214Bi and 228Ac, 212Pb, 208Tl following the decays of the primordial radionuclides 238U and 232Th, respectively. The analysis also includes evaluations for the 235U decay chain. In particular, the 186 keV doublet transition is used together with the activity concentration values established from the decays of 214Bi and 214Pb to establish the 226Ra and 235U specific activity concentrations, which can be used to estimate the 235U:238U isotopic ratios and compare to the accepted value for naturally occurring material of 1:138. Specific activity concentration values have also been determined for the 40K and the anthropogenic radionuclide 137Cs (from fallout) were detected within the same samples. Results of the activity concentration gives mean value of 16.99±0.21, 12.79±0.14, 333±37 and 2.18±0.11 Bq/kg for 238U, 232Th, 40K, and 137Cs, respectively. The associated radiological hazard indices from these samples were found to have mean values of 29.13±0.35 nG/hr, 60.20±0.68 Bq/kg, and 35.30±0.40 µSv/year for the dose rates, radium equivalent, and annual dose equivalent, respectively. Analysed results of elemental concentrations of Uranium, Thorium and Potassium were also determined, and were found to range from 0.96±0.02 ppm to 2.53±0.02 ppm, 2.26±0.04 ppm to 5.23±0.05 ppm and a mean value of 1.21±0

  2. 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)

  3. 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)

  4. Determination of the natural radioactivity levels in north west of Dukhan, Qatar using high-resolution gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Al-Sulaiti, Huda; Nasir, Tabassum; Al Mugren, K.S.; Alkhomashi, N.; Al-Dahan, N.; Al-Dosari, M.; Bradley, D.A.; Bukhari, S.; Matthews, M.; Regan, P.H.; Santawamaitre, T.; Malain, D.; Habib, A.

    2012-01-01

    This study is aimed at the determination of the activity concentrations of naturally occuring and technologically enhanced levels of radiation in 34 representative soil samples that have been collected from an inshore oil field area which was found to have, in a previous study, the highest observed value of 226 Ra concentration among 129 soil samples. The activity concentrations of 238 U and 226 Ra have been inferred from gamma-ray transitions associated with their decay progenies and measured using a hyper-pure germanium detector. Details of the sample preparation and the gamma-ray spectroscopic analysis techniques are presented, together with the values of the activity concentrations associated with the naturally occuring radionuclide chains for all the samples collected from NW Dukhan. Discrete-line, gamma-ray energy transitions from spectral lines ranging in energy from ∼100 keV up to 2.6 MeV have been associated with characteristic decays of the various decay products within the 235.8 U and 232 Th radioactive decay chains. These data have been analyzed, under the assumption of secular equilibrium for the U and Th decay chains. Details of the sample preparation and the gamma-ray spectroscopic analysis techniques are presented. The weighted mean value of the activity concentrations of 226 Ra in one of the samples was found to be around a factor of 2 higher than the values obtained in the previous study and approximately a factor of 10 higher than the accepted worldwide average value of 35 Bq/kg. The weighted mean values of the activity concentrations of 232 Th and 40 K were also deduced and found to be within the worldwide average values of 30 and 400 Bq/kg, respectively. Our previous study reported a value of 201.9±1.5 Stat. ±13 Syst. Bq/kg for 226 Ra in one sample and further investigation in the current work determined a measured value for 226 Ra of 342.00±1.9 Stat. ±25 Syst. Bq/kg in a sample taken from the same locality. This is significantly higher

  5. Determination of the natural radioactivity levels in north west of Dukhan, Qatar using high-resolution gamma-ray spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Al-Sulaiti, Huda [Centre for Nuclear and Radiation Physics, Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Radiation Protection and Chemicals Department, Ministry of Environment, P.O. Box 7634, Doha (Qatar); Nasir, Tabassum [Centre for Nuclear and Radiation Physics, Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Department of Physics, Gomal University, D.I. Khan (Pakistan); Al Mugren, K S [Centre for Nuclear and Radiation Physics, Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Physics Department, Faculty of Sciences, Princess Nora Bint Abdul Rahman University, Riyadh (Saudi Arabia); Alkhomashi, N [King Abdulaziz City of Science and Technology (KACST), P.O. Box 6086, Riyadh 11442 (Saudi Arabia); Al-Dahan, N [Centre for Nuclear and Radiation Physics, Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Department of Physics, College of Science, University of Kerbala, Kerbala (Iraq); Al-Dosari, M [Radiation Protection and Chemicals Department, Ministry of Environment, P.O. Box 7634, Doha (Qatar); Bradley, D A [Centre for Nuclear and Radiation Physics, Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Bukhari, S [Information Systems Management Department, Ministry of Environment, P.O. Box 7634, Doha (Qatar); Matthews, M [Centre of Environmental Health Engineering, Department of Civil Engineering, University of Surrey, Guildford GU2 7XH (United Kingdom); Regan, P H [Centre for Nuclear and Radiation Physics, Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Santawamaitre, T [Radiation Protection and Chemicals Department, Ministry of Environment, P.O. Box 7634, Doha (Qatar); Malain, D; Habib, A [Centre for Nuclear and Radiation Physics, Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom)

    2012-07-15

    This study is aimed at the determination of the activity concentrations of naturally occuring and technologically enhanced levels of radiation in 34 representative soil samples that have been collected from an inshore oil field area which was found to have, in a previous study, the highest observed value of {sup 226}Ra concentration among 129 soil samples. The activity concentrations of {sup 238}U and {sup 226}Ra have been inferred from gamma-ray transitions associated with their decay progenies and measured using a hyper-pure germanium detector. Details of the sample preparation and the gamma-ray spectroscopic analysis techniques are presented, together with the values of the activity concentrations associated with the naturally occuring radionuclide chains for all the samples collected from NW Dukhan. Discrete-line, gamma-ray energy transitions from spectral lines ranging in energy from {approx}100 keV up to 2.6 MeV have been associated with characteristic decays of the various decay products within the {sup 235.8}U and {sup 232}Th radioactive decay chains. These data have been analyzed, under the assumption of secular equilibrium for the U and Th decay chains. Details of the sample preparation and the gamma-ray spectroscopic analysis techniques are presented. The weighted mean value of the activity concentrations of {sup 226}Ra in one of the samples was found to be around a factor of 2 higher than the values obtained in the previous study and approximately a factor of 10 higher than the accepted worldwide average value of 35 Bq/kg. The weighted mean values of the activity concentrations of {sup 232}Th and {sup 40}K were also deduced and found to be within the worldwide average values of 30 and 400 Bq/kg, respectively. Our previous study reported a value of 201.9{+-}1.5{sub Stat.}{+-}13{sub Syst.} Bq/kg for {sup 226}Ra in one sample and further investigation in the current work determined a measured value for {sup 226}Ra of 342.00{+-}1.9{sub Stat.}{+-}25{sub Syst

  6. Determination of the activity concentration levels of the artificial radionuclide137Cs in soil samples collected from Qatar using high-resolution gamma-ray spectrometry

    Science.gov (United States)

    Al-Sulaiti, Huda; Nasir, Tabassum; Al Mugren, K. S.; Alkhomashi, N.; Al-Dahan, N.; Al-Dosari, M.; Bradley, D. A.; Bukhari, S.; Regan, P. H.; Santawamaitre, T.; Malain, D.; Habib, A.; Al-Dosari, Hanan; Daar, Eman

    2016-09-01

    The goal of this study was to establish the first baseline measurements for radioactivity concentration of the artificial radionuclide 137Cs in soil samples collected from the Qatarian peninsula. The work focused on the determination of the activity concentrations levels of man-made radiation in 129 soil samples collected across the landscape of the State of Qatar. All the samples were collected before the most recent accident in Japan, “the 2011 Fukushima Dai-ichi nuclear power plant accident”. The activity concentrations have been measured via high-resolution gamma-ray spectrometry using a hyper-pure germanium detector situated in a low-background environment with a copper inner-plated passive lead shield. A radiological map showing the activity concentrations of 137Cs is presented in this work. The concentration wasfound to range from 0.21 to 15.41 Bq/kg. The highest activity concentration of 137Cs was observed in sample no. 26 in North of Qatar. The mean value was found to be around 2.15 ± 0.27 Bq/kg. These values lie within the expected range relative to the countries in the region. It is expected that this contamination is mainly due to the Chernobyl accident on 26 April 1986, but this conclusion cannot be confirmed because of the lack of data before this accident.

  7. 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

  8. A review of the evaluation of TENORM levels at the produced water lagoon of the Minagish oil field using high-resolution gamma-ray spectrometry

    Science.gov (United States)

    Shams, H. M.; Bradley, D. A.; Alshammari, H.; Regan, P. H.

    2017-11-01

    An evaluation of the specific activity concentrations associated with technologically enhanced naturally occurring radioactive materials (TENORM) and anthropogenic radionuclides has been undertaken as part of a systematic study to provide a radiological map of the outer boundary of the produced water lagoon located in the Minagish oil field in the south west of the State of Kuwait. The lagoon contains material from the discharge of produced water which is a by-product of oil production in the region. The lagoon samples were prepared and placed into sealed, marinelli beakers for a full gamma-ray spectrometric analysis using a high-resolution, low-background, high-purity germanium detection systems at the University of Surrey Environmental Radioactivity Laboratory. Of particular interest are the calculation of the activity concentrations associated with members of the decay chains following decays of the primordial radionuclides of the 238U chain (226Ra, 214Pb, 214Bi) and the 232Th chain (228Ra, 228Ac, 212Pb, 212Bi, 208Tl), and the enhanced concentrations of radium isotopes. This conference paper presents an overview summary of the experimental samples which have been measured and the analysis techniques applied, including isotopic correlation plots across the sample region. The result shows the expected significant increase in 226Ra (and progeny) concentrations compared to the NORM values previously reported by our group for the overall terrain in Kuwait.

  9. High resolution spectrometry for relativistic heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Gabor, G; Schimmerling, W; Greiner, D; Bieser, F; Lindstrom, P [California Univ., Berkeley (USA). Lawrence Berkeley Lab.

    1975-12-01

    Several techniques are discussed for velocity and energy spectrometry of relativistic heavy ions with good resolution. A foil telescope with chevron channel plate detectors is described. A test of this telescope was performed using 2.1 GeV/A C/sup 6 +/ ions, and a time-of-flight resolution of 160 ps was measured. Qualitative information on the effect of foil thickness was also obtained.

  10. High resolution gamma spectroscopy well logging system

    International Nuclear Information System (INIS)

    Giles, J.R.; Dooley, K.J.

    1997-01-01

    A Gamma Spectroscopy Logging System (GSLS) has been developed to study sub-surface radionuclide contamination. The absolute counting efficiencies of the GSLS detectors were determined using cylindrical reference sources. More complex borehole geometries were modeled using commercially available shielding software and correction factors were developed based on relative gamma-ray fluence rates. Examination of varying porosity and moisture content showed that as porosity increases, and as the formation saturation ratio decreases, relative gamma-ray fluence rates increase linearly for all energies. Correction factors for iron and water cylindrical shields were found to agree well with correction factors determined during previous studies allowing for the development of correction factors for type-304 stainless steel and low-carbon steel casings. Regression analyses of correction factor data produced equations for determining correction factors applicable to spectral gamma-ray well logs acquired under non-standard borehole conditions

  11. Isotopic composition of uranium in U3O8 by neutron induced reactions utilizing thermal neutrons from critical facility and high resolution gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Acharya, R.; Pujari, P.K.; Goel, Lokesh

    2015-01-01

    Uranium in oxide and metal forms is used as fuel material in nuclear power reactors. For chemical quality control, it is necessary to know the isotopic composition (IC) of uranium i.e., 235 U to 238 U atom ratio as well as 235 U atom % in addition to its total concentration. Uranium samples can be directly assayed by passive gamma ray spectrometry for obtaining IC by utilizing 185 keV (γ-ray abundance 57.2%) of 235 U and 1001 keV (γ-ray abundance 0.837%) of 234m Pa (decay product of 238 U). However, due to low abundance of 1001 keV, often it is not practiced to obtain IC by this method as it gives higher uncertainty even if higher mass of sample and counting time are used. IC of uranium can be determined using activity ratio of neutron induced fission product of 235 U to activation product of 238 U ( 239 Np). In the present work, authors have demonstrated methodologies for determination of IC of U as well as 235 U atom% in natural ( 235 U 0.715%) and low enriched uranium (LEU, 3-20 atom % of 235 U) samples of uranium oxide (U 3 O 8 ) by utilizing ratio of counts at 185 keV γ-ray or γ-rays of fission products with respect to 277 keV of 239 Np. Natural and enriched samples (about 25 mg) were neutron irradiated for 4 hours in graphite reflector position of AHWR Critical Facility (CF) using highly thermalized (>99.9% thermal component) neutron flux (∼10 7 cm -2 s -1 )

  12. Yeast expression proteomics by high-resolution mass spectrometry

    DEFF Research Database (Denmark)

    Walther, Tobias C; Olsen, Jesper Velgaard; Mann, Matthias

    2010-01-01

    -translational controls contribute majorly to regulation of protein abundance, for example in heat shock stress response. The development of new sample preparation methods, high-resolution mass spectrometry and novel bioinfomatic tools close this gap and allow the global quantitation of the yeast proteome under different...

  13. High Resolution Mass Spectrometry of Polyfluorinated Polyether-Based Formulation

    DEFF Research Database (Denmark)

    Dimzon, Ian Ken; Trier, Xenia; Frömel, Tobias

    2016-01-01

    High resolution mass spectrometry (HRMS) was successfully applied to elucidate the structure of a polyfluorinated polyether (PFPE)-based formulation. The mass spectrum generated from direct injection into the MS was examined by identifying the different repeating units manually and with the aid o......-fluorinated polymers. The information from MS is essential in studying the physico-chemical properties of PFPEs and can help in assessing the risks they pose to the environment and to human health. Graphical Abstract ᅟ....

  14. Burn-Up Determination by High Resolution Gamma Spectrometry: Spectra from Slightly-Irradiated Uranium and Plutonium between 400-830 keV

    Energy Technology Data Exchange (ETDEWEB)

    Forsyth, R S; Ronqvist, N

    1966-08-15

    Previously published studies of the short-cooled fission product spectra of irradiated uranium have been severely restricted by the poor energy resolution of the sodium iodide detectors used. In this report are presented fission product spectra of irradiated uranium and plutonium obtained by means of a lithium-drifted germanium detector. The resolved gamma peaks have been assigned to various fission products by correlation of measured energy and half-life values with published data. By simultaneous study of the spectra of two irradiated mixtures of plutonium and uranium, the possibility of using the activities of Ru-103 and Ru-106 as a measure of the relative fission rate in U-235 and Pu-239 has been briefly examined.

  15. Burn-Up Determination by High Resolution Gamma Spectrometry: Spectra from Slightly-Irradiated Uranium and Plutonium between 400-830 keV

    International Nuclear Information System (INIS)

    Forsyth, R.S.; Ronqvist, N.

    1966-08-01

    Previously published studies of the short-cooled fission product spectra of irradiated uranium have been severely restricted by the poor energy resolution of the sodium iodide detectors used. In this report are presented fission product spectra of irradiated uranium and plutonium obtained by means of a lithium-drifted germanium detector. The resolved gamma peaks have been assigned to various fission products by correlation of measured energy and half-life values with published data. By simultaneous study of the spectra of two irradiated mixtures of plutonium and uranium, the possibility of using the activities of Ru-103 and Ru-106 as a measure of the relative fission rate in U-235 and Pu-239 has been briefly examined

  16. Diesel characterization by high-resolution mass spectrometry - gas chromatography

    International Nuclear Information System (INIS)

    Baldrich, C.A

    1998-01-01

    High-resolution mass spectrometry-gas chromatography is combined with the HC22 method in order to obtain detailed information about the chemical composition of diesel and the distribution of different compound types in terms of its final boiling temperature from a single analysis. The total time elapsed from sample injection and signal processing to obtain final results is 90 minutes. This fact makes this methodology a new and very important tool for the decision making process concerning the most suitable final boiling temperature and the type of treatment of the product in order to obtain diesel that fulfills the international standards. The consistency and repeatability of the experimental results are demonstrated

  17. Application of the Oslo method to high resolution gamma spectra

    Science.gov (United States)

    Simon, A.; Guttormsen, M.; Larsen, A. C.; Beausang, C. W.; Humby, P.

    2015-10-01

    Hauser-Feshbach statistical model is a widely used tool for calculation of the reaction cross section, in particular for astrophysical processes. The HF model requires as an input an optical potential, gamma-strength function (GSF) and level density (LD) to properly model the statistical properties of the nucleus. The Oslo method is a well established technique to extract GSFs and LDs from experimental data, typically used for gamma-spectra obtained with scintillation detectors. Here, the first application of the Oslo method to high-resolution data obtained using the Ge detectors of the STARLITER setup at TAMU is discussed. The GSFs and LDs extracted from (p,d) and (p,t) reactions on 152154 ,Sm targets will be presented.

  18. Bayesian Peptide Peak Detection for High Resolution TOF Mass Spectrometry.

    Science.gov (United States)

    Zhang, Jianqiu; Zhou, Xiaobo; Wang, Honghui; Suffredini, Anthony; Zhang, Lin; Huang, Yufei; Wong, Stephen

    2010-11-01

    In this paper, we address the issue of peptide ion peak detection for high resolution time-of-flight (TOF) mass spectrometry (MS) data. A novel Bayesian peptide ion peak detection method is proposed for TOF data with resolution of 10 000-15 000 full width at half-maximum (FWHW). MS spectra exhibit distinct characteristics at this resolution, which are captured in a novel parametric model. Based on the proposed parametric model, a Bayesian peak detection algorithm based on Markov chain Monte Carlo (MCMC) sampling is developed. The proposed algorithm is tested on both simulated and real datasets. The results show a significant improvement in detection performance over a commonly employed method. The results also agree with expert's visual inspection. Moreover, better detection consistency is achieved across MS datasets from patients with identical pathological condition.

  19. 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

  20. Linking high resolution mass spectrometry data with exposure ...

    Science.gov (United States)

    There is a growing need in the field of exposure science for monitoring methods that rapidly screen environmental media for suspect contaminants. Measurement and analysis platforms, based on high resolution mass spectrometry (HRMS), now exist to meet this need. Here we describe results of a study that links HRMS data with exposure predictions from the U.S. EPA's ExpoCast™ program and in vitro bioassay data from the U.S. interagency Tox21 consortium. Vacuum dust samples were collected from 56 households across the U.S. as part of the American Healthy Homes Survey (AHHS). Sample extracts were analyzed using liquid chromatography time-of-flight mass spectrometry (LC–TOF/MS) with electrospray ionization. On average, approximately 2000 molecular features were identified per sample (based on accurate mass) in negative ion mode, and 3000 in positive ion mode. Exact mass, isotope distribution, and isotope spacing were used to match molecular features with a unique listing of chemical formulas extracted from EPA's Distributed Structure-Searchable Toxicity (DSSTox) database. A total of 978 DSSTox formulas were consistent with the dust LC–TOF/molecular feature data (match score ≥ 90); these formulas mapped to 3228 possible chemicals in the database. Correct assignment of a unique chemical to a given formula required additional validation steps. Each suspect chemical was prioritized for follow-up confirmation using abundance and detection frequency results, along wi

  1. Unattented mode monitoring of high resolution gamma-ray spectra

    International Nuclear Information System (INIS)

    Smith, B.G.R.; Van Dyck, P.; Debraix, P.

    1991-01-01

    An Isotope Monitoring System (IMS) for unattended spectrum acquisition is described. This consists of a simple low cost flexible software package running on a Compaq 80386 and controlling up to 4 Canberra Packard System 100 multi-channel analyzer (MCA) cards. The IMS permits the independent configuration of each of the 4 MCA cards for different monitoring cycles and for different spectrum acquisition cycles each being based upon different trigger criteria. In this way IMS is able to automatically identify events, time tag them, and acquire and store valid spectra corresponding to those event. An additional feature of IMS permits to run a Multigroup Analysis (MGA) software package for the determination of plutonium isotopic compositions in batch mode. One particular application is discussed which consists of 4 high resolution gamma-ray detector systems connected together to the IMS for unattended spectrum acquisition. The off-line batch mode analysis of the spectra using MGA is also discussed

  2. Determination of radium-226 by high-resolution alpha spectrometry

    International Nuclear Information System (INIS)

    Sill, C.W.

    1983-01-01

    The determination of radium-226 by alpha spectrometry has been investigated critically to determine experimental conditions under which high resolution and accurate and reliable results can be obtained. Refractory solids such as soils, ores, and tailings from uranium mills are dissolved completely by fusion with potassium fluoride in the presence of barium-133 tracer. The fluoride cake is then transposed with sulfuric acid to a pyrosulfate fusion with simultaneous volatilization of all silica and fluoride. Radium is precipitated with barium already present in the sample by addition of lead perchlorate to a dilute hydrochloric acid solution of the pyrosulfate cake. The resulting insoluble sulfates are dissolved in an alkaline solution of diethylenetriaminepentaacetic acid, and the radium and barium sulfates are reprecipitated with acetic acid. The precipitate is mounted on a membrane filter and analyzed by alpha spectrometry. Water samples are partially evaporated and treated similarly. Resolution of the subsequent alpha spectra is much better than has been achieved previously from barium sulfate, and is almost as good as is obtainable with actinides electrodeposited on polished steel plates. The resolution is about 60 keV full-width-half-maximum with 100 μg of barium on a 1-inch filter with a 450 mm 2 detector at 20% counting efficiency. Recovery is about 97% and accuracy is generally as good as the counting statistics obtained will permit. Grossly inaccurate results can be obtained under certain conditions when barium-133 tracer is used to determine the chemical yield of radium-226. Severe contamination of the surface-barrier detector by polonium-210 and by recoil products of the radium isotopes being counted is demonstrated, amd methods for virtual elimination of both problems are discussed

  3. HCN Polymers: Toward Structure Comprehension Using High Resolution Mass Spectrometry

    Science.gov (United States)

    Bonnet, Jean-Yves; Thissen, Roland; Frisari, Ma; Vuitton, Veronique; Quirico, Eric; Le Roy, Léna; Fray, Nicolas; Cottin, Hervé; Horst, Sarah; Yelle, Roger

    A lot of solar system materials, including cometary ices and Titan aerosols, contain dark matter that can be interpreted as complex nitrogen bearing organic matter [1]. In laboratory experi-ments, HCN polymers are thus analogs of great interest. In fact they may be present in Titan atmosphere and in comet nuclei and then reprocessed as a CN distributed source [2], when ices began to sublimate and ejects from the nucleus organic matter grains [3]. The presence of HCN polymers is suggested because HCN molecule has been directly observed in 1P/Halley comet [4] and others. HCN polymers are also of prebiotic interest [5] as it can form amino acid under hydrolysis conditions. Even if they have been studied during the last decades, their chemical composition and structure are still poorly understood, and a great analytical effort has to be continued. In this way we present a high resolution mass spectrometry (HRMS) and a high resolution tandem mass spectrometry (MS/HRMS) analysis of HCN polymers. It was shown [6] that this is a suitable technique to elucidate composition and structure of the soluble part of tholins analogs of Titan's atmosphere aerosols. HCN polymers have never been studied by HRMS, thus we used a LTQ-Orbitrap XL high resolution mass spectrometer to analyse the HCN polymers. These are produced at LISA by direct polymerisation of pure liquid HCN, catalyzed by ammonia. HCN polymers have been completely dissolved in methanol and then injected in the mass spectrometer by ElectroSpray Ionization (ESI). This atmospheric pressure ionization process produces protonated or deprotonated ions, but it does not fragment molecules. Thus HRMS, allows a direct access to the stoechiometry of all the ionizable molecules present in the samples. Fragmentation analyses (MS/MS) of selected ions have also been performed. Thess analysis provide information about the different chemical fonctionnalities present in HCN poly-mers and also about their structure. Thus we are able to

  4. Determination of radium-226 by high-resolution alpha spectrometry

    International Nuclear Information System (INIS)

    Sill, C.W.

    1983-01-01

    Condition were determined under which high resolution and accurate and reliable results can be obtained. Refractory solids are dissolved completely by fusion with KF and Ba-133 tracer. The fluoride cake is then transposed with sulfuric acid to a pyrosulfate fusion. Radium is precipitated with barium by addition of lead perchlorate to a dilute HCl solution of the pyrosulfate cake. The resulting insoluble sulfates are dissolved in an alkaline solution of DTPA and the Ra and Ba sulfates are reprecipitated with acetic acid to produce very small crystals. The precipitate is mounted on 0.1-μm membrane filter and analyzed by alpha spectrometry. Water samples are partially evaporated and treated similarly. Resolution, almost as good as with actinides electrodeposited on polished steel plates, is about 60 keV full-width-half-maximum with 100 μg of barium on a 1-inch filter with a 450 mm 2 detector at 20% counting efficiency. Recovery is about 97%. One solid sample can be prepared for counting in less than 2 hours. Methods are discussed for ensuring reliability of the results. Severe contamination of the surface-barrier detector by polonium-210 and recoil products is discussed

  5. High Resolution Mass Spectrometry of Polyfluorinated Polyether-Based Formulation

    Science.gov (United States)

    Dimzon, Ian Ken; Trier, Xenia; Frömel, Tobias; Helmus, Rick; Knepper, Thomas P.; de Voogt, Pim

    2016-02-01

    High resolution mass spectrometry (HRMS) was successfully applied to elucidate the structure of a polyfluorinated polyether (PFPE)-based formulation. The mass spectrum generated from direct injection into the MS was examined by identifying the different repeating units manually and with the aid of an instrument data processor. Highly accurate mass spectral data enabled the calculation of higher-order mass defects. The different plots of MW and the nth-order mass defects (up to n = 3) could aid in assessing the structure of the different repeating units and estimating their absolute and relative number per molecule. The three major repeating units were -C2H4O-, -C2F4O-, and -CF2O-. Tandem MS was used to identify the end groups that appeared to be phosphates, as well as the possible distribution of the repeating units. Reversed-phase HPLC separated of the polymer molecules on the basis of number of nonpolar repeating units. The elucidated structure resembles the structure in the published manufacturer technical data. This analytical approach to the characterization of a PFPE-based formulation can serve as a guide in analyzing not just other PFPE-based formulations but also other fluorinated and non-fluorinated polymers. The information from MS is essential in studying the physico-chemical properties of PFPEs and can help in assessing the risks they pose to the environment and to human health.

  6. Quantitation of Acrylamide in Foods by High-Resolution Mass Spectrometry

    NARCIS (Netherlands)

    Troise, A.D.; Fogliano, Vincenzo

    2016-01-01

    The use of liquid chromatography high-resolution mass spectrometry (LC-HRMS) and direct analysis real-time high-resolution mass spectrometry (DART-HRMS) defines a new scenario in the analysis of thermal-induced toxicants, such as acrylamide. Several factors contribute to the definition of the

  7. Recent applications of gas chromatography with high-resolution mass spectrometry.

    Science.gov (United States)

    Špánik, Ivan; Machyňáková, Andrea

    2018-01-01

    Gas chromatography coupled to high-resolution mass spectrometry is a powerful analytical method that combines excellent separation power of gas chromatography with improved identification based on an accurate mass measurement. These features designate gas chromatography with high-resolution mass spectrometry as the first choice for identification and structure elucidation of unknown volatile and semi-volatile organic compounds. Gas chromatography with high-resolution mass spectrometry quantitative analyses was previously focused on the determination of dioxins and related compounds using magnetic sector type analyzers, a standing requirement of many international standards. The introduction of a quadrupole high-resolution time-of-flight mass analyzer broadened interest in this method and novel applications were developed, especially for multi-target screening purposes. This review is focused on the development and the most interesting applications of gas chromatography coupled to high-resolution mass spectrometry towards analysis of environmental matrices, biological fluids, and food safety since 2010. The main attention is paid to various approaches and applications of gas chromatography coupled to high-resolution mass spectrometry for non-target screening to identify contaminants and to characterize the chemical composition of environmental, food, and biological samples. The most interesting quantitative applications, where a significant contribution of gas chromatography with high-resolution mass spectrometry over the currently used methods is expected, will be discussed as well. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Some deficiencies and solutions in gamma ray spectrometry

    International Nuclear Information System (INIS)

    Westmeier, W.

    1998-01-01

    A number of problems in high-resolution gamma ray spectrometry as well as some deficiencies of existing computer programs for the quantitative evaluation of spectra are discussed and some practical solutions are proposed. (author)

  9. 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.

  10. 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)

  11. In-situ high-resolution gamma-spectrometric survey of burial ground-monitoring wells

    International Nuclear Information System (INIS)

    Bowman, W.W.

    1981-09-01

    In situ high resolution gamma-ray spectrometry with an intrinsic germanium detector assembly of special design surveyed the burial ground monitoring wells to locate and identify gamma emitters that may have migrated from the burial trenches toward the water table. Gamma-ray spectra were acquired as a function of depth in each well and recorded on magnetic tape. These spectra were reduced by a series of computer programs to produce count rate versus depth profiles for natural and man-made activities. The original spectra and the profiles have been archived on magnetic tape for comparison with similar future surveys. Large amounts of man-made activities were observed in some of the burial trenches; however, below the trench bottoms, only very low but detectable amounts of 60 Co and 137 Cs were observed in eleven wells. The highest level of man-made gamma activity observed below the trench bottoms has a count rate roughly equal to that observed for uranium daughter activities which are natural to the subsoil

  12. High-Resolution Fast-Neutron Spectrometry for Arms Control and Treaty Verification

    Energy Technology Data Exchange (ETDEWEB)

    David L. Chichester; James T. Johnson; Edward H. Seabury

    2012-07-01

    Many nondestructive nuclear analysis techniques have been developed to support the measurement needs of arms control and treaty verification, including gross photon and neutron counting, low- and high-resolution gamma spectrometry, time-correlated neutron measurements, and photon and neutron imaging. One notable measurement technique that has not been extensively studied to date for these applications is high-resolution fast-neutron spectrometry (HRFNS). Applied for arms control and treaty verification, HRFNS has the potential to serve as a complimentary measurement approach to these other techniques by providing a means to either qualitatively or quantitatively determine the composition and thickness of non-nuclear materials surrounding neutron-emitting materials. The technique uses the normally-occurring neutrons present in arms control and treaty verification objects of interest as an internal source of neutrons for performing active-interrogation transmission measurements. Most low-Z nuclei of interest for arms control and treaty verification, including 9Be, 12C, 14N, and 16O, possess fast-neutron resonance features in their absorption cross sections in the 0.5- to 5-MeV energy range. Measuring the selective removal of source neutrons over this energy range, assuming for example a fission-spectrum starting distribution, may be used to estimate the stoichiometric composition of intervening materials between the neutron source and detector. At a simpler level, determination of the emitted fast-neutron spectrum may be used for fingerprinting 'known' assemblies for later use in template-matching tests. As with photon spectrometry, automated analysis of fast-neutron spectra may be performed to support decision making and reporting systems protected behind information barriers. This paper will report recent work at Idaho National Laboratory to explore the feasibility of using HRFNS for arms control and treaty verification applications, including simulations

  13. Multidimensional analysis of high resolution. gamma. -ray data

    Energy Technology Data Exchange (ETDEWEB)

    Flibotte, S.; Huettmeier, U.J.; France, G. de; Haas, B.; Romain, P.; Theisen, C.; Vivien, J.P.; Zen, J. (Centre de Recherches Nucleaires, 67 - Strasbourg (France)); Bednarczyk, P. (Inst. of Nuclear Physics, Krakow (Poland))

    1992-08-15

    Algorithms are developed to analyze high-fold {gamma}-ray coincidences. Performances of the programs have been tested in 3, 4 and 5 dimensions using events generated with a Monte Carlo simulation. (orig.).

  14. Application of high resolution x-ray spectrometry preceded by neutron activation for elemental analysis of soil samples

    International Nuclear Information System (INIS)

    Hernandez Rivero, A.; Capote Rodriguez, G.; Padilla Alvarez, R.; Herrera Peraza, E.

    1997-01-01

    Utilization of High Resolution X-Ray Spectrometry preceded by activation of the samples by irradiation with neutron fluxes (NAA-RX) is a relatively modern trend in application of nuclear techniques. This method may complement advantageously the usual Neutron Activation Analysis by means of Gamma Spectrometry (NAA-G). In this work results obtained by the application of NAA-RX for non-destructive analysis of Cuban soil samples are discussed. The samples were irradiated with reactor neutron fluxes and the induced characteristic X-rays were measured by using Si(Li)-detector. Concentrations of Fe, Zn and Eu as determined by NAA-RX are compared with both NAA-G and XRF data. For the elaboration of X-Ray and Gamma Spectra the computer programs AXIL and ACTAN were used respectively. (author) [es

  15. Application of high resolution x-ray spectrometry preceded by neutron activation for elemental analysis of soil samples

    International Nuclear Information System (INIS)

    Hernandez Rivero, A.; Capote Rodriguez, G.; Herrera Peraza, E.

    1996-01-01

    Utilization of High Resolution X-Ray Spectrometry preceded by activation of the samples by irradiation with neutron fluxes (NAA R X) is a relatively modern trend in application of nuclear techniques. This method may complement advantageously the usual Neutron Activation Analysis by means of Gamma Spectrometry (NAA-G) In this work results obtained by the application of NAA-RX for non-destructive analysis of Cuban soil samples are discussed. The samples were irradiated with reactor neutron fluxes and the induced characteristic X-rays were measured by using Si(li)-detector. Concentrations of Fe, Zn and Eu as determined by NAA-RX are compared with both NAA-G and XRF data. For the elaboration of X-ray and Gamma Spectra the computer programs AXIL and ACTAN were used respectively

  16. High Resolution Gamma Ray Analysis of Medical Isotopes

    Science.gov (United States)

    Chillery, Thomas

    2015-10-01

    Compton-suppressed high-purity Germanium detectors at the University of Massachusetts Lowell have been used to study medical radioisotopes produced at Brookhaven Linac Isotope Producer (BLIP), in particular isotopes such as Pt-191 used for cancer therapy in patients. The ability to precisely analyze the concentrations of such radio-isotopes is essential for both production facilities such as Brookhaven and consumer hospitals across the U.S. Without accurate knowledge of the quantities and strengths of these isotopes, it is possible for doctors to administer incorrect dosages to patients, thus leading to undesired results. Samples have been produced at Brookhaven and shipped to UML, and the advanced electronics and data acquisition capabilities at UML have been used to extract peak areas in the gamma decay spectra. Levels of Pt isotopes in diluted samples have been quantified, and reaction cross-sections deduced from the irradiation parameters. These provide both cross checks with published work, as well as a rigorous quantitative framework with high quality state-of-the-art detection apparatus in use in the experimental nuclear physics community.

  17. HPGe detectors long time behaviour in high-resolution γ spectrometry

    International Nuclear Information System (INIS)

    Sajo-Bohus, L.; Rosso, D.; Sajo Castelli, A.M.; Napoli, D.R.; Fioretto, E.; Menegazzo, R.; Barros, H.; Ur, C.A.; Palacios, D.; Liendo, J.

    2011-01-01

    A large set of data on long term performance of n-type HPGe detectors used in GASP, EUROBALL and CLARA γ spectrometers, as well as environmental measurements have been collected over two decades. In this paper a detailed statistical analysis of this data is given and detector long term behaviour is provided to the scientific community. We include failure, failure mode, repair frequency, repair outcome and its influence in the energy efficiency and energy resolution. A remarkable result is that the life span distribution is exponential. A detector's failure is a memory-less process, where a previous failure does not influence the upcoming one. Repaired spectrometers result in high reliability with deep implications in the management of large scale high-resolution gamma spectrometry related projects. Findings show that on average, detectors initial counting efficiency is slightly lower (∼2%) than that reported by the manufacturers and the repair process (including annealing) does not affect significantly the energy efficiency, even after a long period of use. Repaired detector energy resolution statistics show that the probability, that a repaired detector will be at least as good as it was originally, is more than 3/4.

  18. Gold finger formation studied by high-resolution mass spectrometry and in silico methods

    NARCIS (Netherlands)

    Laskay, Ü.A.; Garino, C.; Tsybin, Y.O.; Salassa, L.; Casini, A.

    2015-01-01

    High-resolution mass spectrometry and quantum mechanics/molecular mechanics studies were employed for characterizing the formation of two gold finger (GF) domains from the reaction of zinc fingers (ZF) with gold complexes. The influence of both the gold oxidation state and the ZF coordination sphere

  19. CeBr3 as a room-temperature, high-resolution gamma-ray detector

    International Nuclear Information System (INIS)

    Guss, Paul; Reed, Michael; Yuan Ding; Reed, Alexis; Mukhopadhyay, Sanjoy

    2009-01-01

    Cerium bromide (CeBr 3 ) has become a material of interest in the race for high-resolution gamma-ray spectroscopy at room temperature. This investigation quantified the potential of CeBr 3 as a room-temperature, high-resolution gamma-ray detector. The performance of CeBr 3 crystals was compared to other scintillation crystals of similar dimensions and detection environments. Comparison of self-activity of CeBr 3 to cerium-doped lanthanum tribromide (LaBr 3 :Ce) was performed. Energy resolution and relative intrinsic efficiency were measured and are presented.

  20. Evaluation of high-resolution mass spectrometry for urine toxicology screening in a pain management setting.

    Science.gov (United States)

    Crews, Bridgit O; Pesce, Amadeo J; West, Robert; Nguyen, Hugh; Fitzgerald, Robert L

    2012-01-01

    To evaluate liquid chromatography-high-resolution mass spectrometry (LC-HR-MS) for urine toxicology screening, 29 analytes were quantitated in 152 urine specimens from patients with chronic pain using two unique mass spectrometry platforms. De-identified specimens were quantitated in April of 2011 by liquid chromatography-triple quadrupole mass spectrometry (LC-MS-MS) and by full-scan LC-HR-MS at Millennium Laboratories. Considering LC-MS-MS as the reference method, false positive results were identified in 19 specimens measured by LC-HR-MS. Application of relative retention times using deuterium labeled internal standards improved the rate of false positive detection to only five specimens, with four occurring for the same analyte. Ultra-high-resolution mass spectrometry (R = 100,000 at m/z 200) showed no improvement over high-resolution mass spectrometry (R = 10,000 at m/z 200) in the number of false positives detected. Quantitative results measured by LC-MS-MS and LC-HR-MS showed good agreement over four orders of dynamic range. This study demonstrates that LC-HR-MS is a suitable platform for toxicology screening for a pain management population and that quantitative accuracy and sensitivity are comparable to that achieved with LC-MS-MS. The specificity of LC-HR-MS is improved by the addition of deuterium labeled internal standards and the implementation of relative retention time matching.

  1. An efficiency study of a high resolution gamma-ray spectrometer

    International Nuclear Information System (INIS)

    Marti Climent, J.M.

    1987-01-01

    A review of the different curves for the efficiency fit of a high resolution gamma-ray spectrometer was made. These curves are used to fit the efficiency of our detector system. In order to study the goodness of the different fits various standards were used, and the ICRP GAM-83 exercise results were employed. (author)

  2. Electrochemistry-High Resolution Mass Spectrometry to Study Oxidation Products of Trimethoprim

    Directory of Open Access Journals (Sweden)

    Marc-André Lecours

    2018-01-01

    Full Text Available The study of the fate of emerging organic contaminants (EOCs, especially the identification of transformation products, after water treatment or in the aquatic environment, is a topic of growing interest. In recent years, electrochemistry coupled to mass spectrometry has attracted a lot of attention as an alternative technique to investigate oxidation metabolites of organic compounds. The present study used different electrochemical approaches, such as cyclic voltammetry, electrolysis, electro-assisted Fenton reaction coupled offline to high resolution mass spectrometry and thin-layer flow cell coupled online to high resolution mass spectrometry, to study oxidation products of the anti-infective trimethoprim, a contaminant of emerging concern frequently reported in wastewaters and surface waters. Results showed that mono- and di-hydroxylated derivatives of trimethoprim were generated in electrochemically and possibly tri-hydroxylated derivatives as well. Those compounds have been previously reported as mammalian and bacterial metabolites as well as transformation products of advance oxidation processes applied to waters containing trimethoprim. Therefore, this study confirmed that electrochemical techniques are relevant not only to mimic specific biotransformation reactions of organic contaminants, as it has been suggested previously, but also to study the oxidation reactions of organic contaminants of interest in water treatment. The key role that redox reactions play in the environment make electrochemistry-high resolution mass spectrometry a sensitive and simple technique to improve our understanding of the fate of organic contaminants in the environment.

  3. The dynamic range of ultra-high-resolution cryogenic gamma-ray spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Shafinaz [Advanced Detector Group, Lawrence Livermore National Laboratory, 7000 East Avenue, L-270, Livermore, CA 94550 (United States); Terracol, Stephane F. [Advanced Detector Group, Lawrence Livermore National Laboratory, 7000 East Avenue, L-270, Livermore, CA 94550 (United States); Drury, Owen B. [Advanced Detector Group, Lawrence Livermore National Laboratory, 7000 East Avenue, L-270, Livermore, CA 94550 (United States); Friedrich, Stephan [Advanced Detector Group, Lawrence Livermore National Laboratory, 7000 East Avenue, L-270, Livermore, CA 94550 (United States)]. E-mail: friedrich1@llnl.gov

    2006-04-15

    We are developing high-resolution cryogenic gamma-ray spectrometers for nuclear science and non-proliferation applications. The gamma-ray detectors are composed of a bulk superconducting Sn foil absorber attached to a multilayer Mo/Cu transition-edge sensor (TES). The energy resolution of a detector with a 1x1x0.25 mm{sup 3} Sn absorber is 50-90 eV FWHM for {gamma}-rays up to 100 keV, and it decreases for larger absorbers. Here, we present the detector performance for different absorber volumes, and discuss the trade-offs between energy resolution and dynamic range.

  4. Calibration of the High Resolution Gamma Spectrometry Detection Systems from the Environmental Radioactivity Unit and Radiological Surveillance (ARU and RV); Calibracion de los Sistemas Detectores de Espectrometria Gamma de Alta Resolucion de la Unidad de Radiactividad Ambiental y Vigilancia Radiologica (URA y VR)

    Energy Technology Data Exchange (ETDEWEB)

    Suarez-Navarro, J. A.; Gasco, C.; Arana, M.; Suanez, A.

    2012-11-01

    In accordance with international regulations and with the quality criteria imposed by the internal quality system of the laboratory of gamma spectrometry, which belongs to the Unit of Environmental Radioactivity and Radiation Monitoring (URA y VR), it is necessary to perform a periodic calibration of the measurement systems of gamma spectrometry. The equipment calibration carries with the need for the preparation of the geometries of measurement and calibration in energy and in efficiencies. This report reflects the procedures for the preparation of the wide range of geometries available in the laboratory, as well as the different calibrations performed with those geometries in almost all the laboratory gamma detectors using the CANBERRA software Genie 2k. (Author) 9 refs.

  5. Molecular composition of organic aerosols in central Amazonia: an ultra-high-resolution mass spectrometry study

    OpenAIRE

    Kourtchev, I; Godoi, RHM; Connors, S; Levine, JG; Archibald, AT; Godoi, AFL; Paralovo, SL; Barbosa, CGG; Souza, RAF; Manzi, AO; Seco, R; Sjostedt, S; Park, J-H; Guenther, A; Kim, S

    2016-01-01

    The Amazon Basin plays key role in atmospheric chemistry, biodiversity and climate change. In this study we applied nanoelectrospray (nanoESI) ultra-high-resolution mass spectrometry (UHRMS) for the analysis of the organic fraction of PM$_{2.5}$ aerosol samples collected during dry and wet seasons at a site in central Amazonia receiving background air masses, biomass burning and urban pollution. Comprehensive mass spectral data evaluation methods (e.g. Kendrick mass defect, Van Krevelen diagr...

  6. High-resolution gamma-ray measurement systems using a compact electro- mechanically cooled detector system and intelligent software

    International Nuclear Information System (INIS)

    Buckley, W.M.; Carlson, J.B.; Neufeld, K.W.

    1995-01-01

    Obtaining high-resolution gamma-ray measurements using high-purity germanium (HPGe) detectors in the field has been of limited practicality due to the need to use and maintain a supply of liquid nitrogen (LN 2 ). This same constraint limits high-resolution gamma measurements in unattended safeguards or treaty Verification applications. We are developing detectors and software to greatly extend the applicability of high-resolution germanium-based measurements for these situations

  7. The Dynamic Range of Ultra-High Resolution Cryogenic Gamma-ray Spectrometers

    International Nuclear Information System (INIS)

    Ali, S; Terracol, S F; Drury, O B; Friedrich, S

    2005-01-01

    We are developing high-resolution cryogenic gamma-ray spectrometers for nuclear science and non-proliferation applications. The gamma-ray detectors are composed of a bulk superconducting Sn foil absorber attached to multilayer Mo/Cu transition-edge sensors (TES). The energy resolution achieved with a 1 x 1 x 0.25 mm 3 Sn absorber is 50 -90eV for γ-rays up to 100 keV and it decreases for large absorber sizes. We discuss the trade-offs between energy resolution and dynamic range, as well as development of TES arrays for higher count rates and better sensitivity

  8. Ultra-high-resolution alpha spectrometry for nuclear forensics and safeguards applications

    International Nuclear Information System (INIS)

    Bacrania, Minesh K.; Croce, Mark; Bond, Evelyn; Dry, Donald; Moody, W. Allen; Lamont, Stephen; Rabin, Michael; Rim, Jung; Smith, Audrey; Beall, James; Bennett, Douglas; Kotsubo, Vincent; Horansky, Robert; Hilton, Gene; Schmidt, Daniel; Ullom, Joel; Cantor, Robin

    2010-01-01

    We will present our work on the development of ultra-high-resolution detectors for alpha particle spectrometry. These detectors, based on superconducting transition-edge sensors, offer energy resolution that is five to ten times better than conventional silicon detectors. Using these microcalorimeter detectors, the isotopic composition of mixed-actinide samples can be determined rapidly without the need for actinide separation chemistry to isolate each element, or mass spectrometry to separate isotopic signatures that can not be resolved using traditional alpha spectrometry (e.g. Pu-239/Pu-240, or Pu-238/Am-241). This paper will cover the detector and measurement system, actinide source preparation, and the quantitative isotopic analysis of a number of forensics- and safeguards-relevant radioactive sources.

  9. High-resolution mass spectrometry in toxicology: current status and future perspectives.

    Science.gov (United States)

    Maurer, H H; Meyer, Markus R

    2016-09-01

    This paper reviews high-resolution mass spectrometry (HRMS) approaches using time-of-flight or Orbitrap techniques for research and application in various toxicology fields, particularly in clinical toxicology and forensic toxicology published since 2013 and referenced in PubMed. In the introduction, an overview on applications of HRMS in various toxicology fields is given with reference to current review articles. Papers concerning HRMS in metabolism, screening, and quantification of pharmaceuticals, drugs of abuse, and toxins in human body samples are critically reviewed. Finally, a discussion on advantages as well as limitations and future perspectives of these methods is included.

  10. 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

  11. High-resolution, three-step resonance ionization mass spectrometry of gadolinium

    International Nuclear Information System (INIS)

    Blaum, K.; Wendt, K.; Bushaw, B.A.; Noertershaeuser, W.

    2001-01-01

    High-resolution resonance ionization mass spectrometry has been used to measure triple-resonance autoionization (AI) spectra of gadolinium. Al resonances as narrow as 10 MHz have been observed and isotope shifts and hyperfine structure have been measured in selected AI states. The strongest AI state observed at 49663.576 cm-1 with a photoionization cross section of >3.6x10 -15 cm 2 was found to have an overall detection efficiency of >3x10 -5 , allowing application to a number of ultratrace determination problems. Analytical measurements with a diode-laser-based system have been successfully performed on bio-medical tissue samples

  12. Automated, feature-based image alignment for high-resolution imaging mass spectrometry of large biological samples

    NARCIS (Netherlands)

    Broersen, A.; Liere, van R.; Altelaar, A.F.M.; Heeren, R.M.A.; McDonnell, L.A.

    2008-01-01

    High-resolution imaging mass spectrometry of large biological samples is the goal of several research groups. In mosaic imaging, the most common method, the large sample is divided into a mosaic of small areas that are then analyzed with high resolution. Here we present an automated alignment

  13. Profiling of integral membrane proteins and their post translational modifications using high-resolution mass spectrometry

    Science.gov (United States)

    Souda, Puneet; Ryan, Christopher M.; Cramer, William A.; Whitelegge, Julian

    2011-01-01

    Integral membrane proteins pose challenges to traditional proteomics approaches due to unique physicochemical properties including hydrophobic transmembrane domains that limit solubility in aqueous solvents. A well resolved intact protein molecular mass profile defines a protein’s native covalent state including post-translational modifications, and is thus a vital measurement toward full structure determination. Both soluble loop regions and transmembrane regions potentially contain post-translational modifications that must be characterized if the covalent primary structure of a membrane protein is to be defined. This goal has been achieved using electrospray-ionization mass spectrometry (ESI-MS) with low-resolution mass analyzers for intact protein profiling, and high-resolution instruments for top-down experiments, toward complete covalent primary structure information. In top-down, the intact protein profile is supplemented by gas-phase fragmentation of the intact protein, including its transmembrane regions, using collisionally activated and/or electroncapture dissociation (CAD/ECD) to yield sequence-dependent high-resolution MS information. Dedicated liquid chromatography systems with aqueous/organic solvent mixtures were developed allowing us to demonstrate that polytopic integral membrane proteins are amenable to ESI-MS analysis, including top-down measurements. Covalent post-translational modifications are localized regardless of their position in transmembrane domains. Top-down measurements provide a more detail oriented high-resolution description of post-transcriptional and post-translational diversity for enhanced understanding beyond genomic translation. PMID:21982782

  14. Structural characterization of suppressor lipids by high-resolution mass spectrometry

    DEFF Research Database (Denmark)

    Rovillos, Mary Joy; Pauling, Josch Konstantin; Hannibal-Bach, Hans Kristian

    2016-01-01

    RATIONALE: Suppressor lipids were originally identified in 1993 and reported to encompass six lipid classes that enable Saccharomyces cerevisiae to live without sphingolipids. Structural characterization, using non-mass spectrometric approaches, revealed that these suppressor lipids are very long...... chain fatty acid (VLCFA)-containing glycerophospholipids with polar head groups that are typically incorporated into sphingolipids. Here we report, for the first time, the structural characterization of the yeast suppressor lipids using high-resolution mass spectrometry. METHODS: Suppressor lipids were...... isolated by preparative chromatography and subjected to structural characterization using hybrid quadrupole time-of-flight and ion trap-orbitrap mass spectrometry. RESULTS: Our investigation recapitulates the overall structural features of the suppressor lipids and provides an in-depth characterization...

  15. Simulation study for high resolution alpha particle spectrometry with mesh type collimator

    International Nuclear Information System (INIS)

    Park, Seunghoon; Kwak, Sungwoo; Kang, Hanbyeol; Shin, Jungki; Park, Iljin

    2014-01-01

    An alpha particle spectrometry with a mesh type collimator plays a crucial role in identifying specific radionuclide in a radioactive source collected from the atmosphere or environment. The energy resolution is degraded without collimation because particles with a high angle have a longer path to travel in the air. Therefore, collision with the background increases. The collimator can cut out particles which traveling at a high angle. As a result, an energy distribution with high resolution can be obtained. Therefore, the mesh type collimator is simulated for high resolution alpha particle spectrometry. In conclusion, the collimator can improve resolution. With collimator, the collimator is a role of cutting out particles with a high angle, so, low energy tail and broadened energy distribution can be reduced. The mesh diameter is found out as an important factor to control resolution and counting efficiency. Therefore, a target particle, for example, 235 U, can be distinguished by a detector with a collimator under a mixture of various nuclides, for example: 232 U, 238 U, and 232 Th

  16. Fingerprints of flower absolutes using supercritical fluid chromatography hyphenated with high resolution mass spectrometry.

    Science.gov (United States)

    Santerre, Cyrille; Vallet, Nadine; Touboul, David

    2018-06-02

    Supercritical fluid chromatography hyphenated with high resolution mass spectrometry (SFC-HRMS) was developed for fingerprint analysis of different flower absolutes commonly used in cosmetics field, especially in perfumes. Supercritical fluid chromatography-atmospheric pressure photoionization-high resolution mass spectrometry (SFC-APPI-HRMS) technique was employed to identify the components of the fingerprint. The samples were separated with a porous graphitic carbon (PGC) Hypercarb™ column (100 mm × 2.1 mm, 3 μm) by gradient elution using supercritical CO 2 and ethanol (0.0-20.0 min (2-30% B), 20.0-25.0 min (30% B), 25.0-26.0 min (30-2% B) and 26.0-30.0 min (2% B)) as mobile phase at a flow rate of 1.5 mL/min. In order to compare the SFC fingerprints between five different flower absolutes: Jasminum grandiflorum absolutes, Jasminum sambac absolutes, Narcissus jonquilla absolutes, Narcissus poeticus absolutes, Lavandula angustifolia absolutes from different suppliers and batches, the chemometric procedure including principal component analysis (PCA) was applied to classify the samples according to their genus and their species. Consistent results were obtained to show that samples could be successfully discriminated. Copyright © 2018 Elsevier B.V. All rights reserved.

  17. Improved yield of high resolution mercuric iodide gamma-ray spectrometers

    International Nuclear Information System (INIS)

    Gerrish, V.; van den Berg, L.

    1990-01-01

    Mercuric iodide (HgI 2 ) exhibits properties which make it attractive for use as a solid state nuclear radiation detector. The wide bandgap (E g = 2.1 eV) and low dark current allow room temperature operation, while the high atomic number provides a large gamma-ray cross section. However, poor hole transport has been a major limitation in the routine fabrication of high-resolution spectrometers using this material. This paper presents the results of gamma-ray response and charge transport parameter measurements conducted during the past year at EG ampersand G/EM on 96 HgI 2 spectrometers. The gamma-ray response measurements reveal that detector quality is correlated with the starting material used in the crystal growth. In particular, an increased yield of high-resolution spectrometers was obtained from HgI 2 which was synthesized by precipitation from an aqueous solution, as opposed to using material from commercial vendors. Data are also presented which suggest that better spectrometer performance is tied to improved hole transport. Finally, some initial results on a study of detector uniformity reveal spatial variations which may explain why the correlation between hole transport parameters and spectrometer performance is sometimes violated. 6 refs., 3 figs

  18. Gamma-ray spectrometer system with high efficiency and high resolution

    International Nuclear Information System (INIS)

    Moss, C.E.; Bernard, W.; Dowdy, E.J.; Garcia, C.; Lucas, M.C.; Pratt, J.C.

    1983-01-01

    Our gamma-ray spectrometer system, designed for field use, offers high efficiency and high resolution for safeguards applications. The system consists of three 40% high-purity germanium detectors and a LeCroy 3500 data acquisition system that calculates a composite spectrum for the three detectors. The LeCroy 3500 mainframe can be operated remotely from the detector array with control exercised through modems and the telephone system. System performance with a mixed source of 125 Sb, 154 Eu, and 155 Eu confirms the expected efficiency of 120% with the overall resolution showing little degradation over that of the worst detector

  19. Quantification of steroid hormones in human serum by liquid chromatography-high resolution tandem mass spectrometry.

    Science.gov (United States)

    Matysik, Silke; Liebisch, Gerhard

    2017-12-01

    A limited specificity is inherent to immunoassays for steroid hormone analysis. To improve selectivity mass spectrometric analysis of steroid hormones by liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been introduced in the clinical laboratory over the past years usually with low mass resolution triple-quadrupole instruments or more recently by high resolution mass spectrometry (HR-MS). Here we introduce liquid chromatography-high resolution tandem mass spectrometry (LC-MS/HR-MS) to further increase selectivity of steroid hormone quantification. Application of HR-MS demonstrates an enhanced selectivity compared to low mass resolution. Separation of isobaric interferences reduces background noise and avoids overestimation. Samples were prepared by automated liquid-liquid extraction with MTBE. The LC-MS/HR-MS method using a quadrupole-Orbitrap analyzer includes eight steroid hormones i.e. androstenedione, corticosterone, cortisol, cortisone, 11-deoxycortisol, 17-hydroxyprogesterone, progesterone, and testosterone. It has a run-time of 5.3min and was validated according to the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA) guidelines. For most of the analytes coefficient of variation were 10% or lower and LOQs were determined significantly below 1ng/ml. Full product ion spectra including accurate masses substantiate compound identification by matching their masses and ratios with authentic standards. In summary, quantification of steroid hormones by LC-MS/HR-MS is applicable for clinical diagnostics and holds also promise for highly selective quantification of other small molecules. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Applied gamma-ray spectrometry

    CERN Document Server

    Dams, R; Crouthamel, Carl E

    1970-01-01

    Applied Gamma-Ray Spectrometry covers real life application of the gamma-ray and the devices used in their experimental studies. This book is organized into 9 chapters, and starts with discussions of the various decay processes, the possible interaction mechanisms of gamma radiation with matter, and the intrinsic and extrinsic variables, which affect the observed gamma-ray and X-ray spectra. The subsequent chapters deal with the properties and fabrication of scintillation detectors, semiconductor detectors, and proportional gas counters. These chapters present some of the most widely utilized

  1. Multi-dimensional analysis of high resolution {gamma}-ray data

    Energy Technology Data Exchange (ETDEWEB)

    Flibotte, S.; Huettmeier, U.J.; France, G. de; Haas, B.; Romain, P.; Theisen, Ch.; Vivien, J.P.; Zen, J. [Strasbourg-1 Univ., 67 (France). Centre de Recherches Nucleaires

    1992-12-31

    A new generation of high resolution {gamma}-ray spectrometers capable of recording high-fold coincidence events with a large efficiency will soon be available. Algorithms are developed to analyze high-fold {gamma}-ray coincidences. As a contribution to the software development associated with the EUROGAM spectrometer, the performances of computer codes designed to select multi-dimensional gates from 3-, 4- and 5-fold coincidence databases were tested. The tests were performed on events generated with a Monte Carlo simulation and also on real experimental triple data recorded with the 8{pi} spectrometer and with a preliminary version of the EUROGAM array. (R.P.) 14 refs.; 3 figs.; 3 tabs.

  2. High resolution gamma-ray spectroscopy applied to bulk sample analysis

    International Nuclear Information System (INIS)

    Kosanke, K.L.; Koch, C.D.; Wilson, R.D.

    1980-01-01

    A high resolution Ge(Li) gamma-ray spectrometer has been installed and made operational for use in routine bulk sample analysis by the Bendix Field Engineering Corporation (BFEC) geochemical analysis department. The Ge(Li) spectrometer provides bulk sample analyses for potassium, uranium, and thorium that are superior to those obtained by the BFEC sodium iodide spectrometer. The near term analysis scheme permits a direct assay for uranium that corrects for bulk sample self-absorption effects and is independent of the uranium/radium disequilibrium condition of the sample. A more complete analysis scheme has been developed that fully utilizes the gamma-ray data provided by the Ge(Li) spectrometer and that more properly accounts for the sample self-absorption effect. This new analysis scheme should be implemented on the BFEC Ge(Li) spectrometer at the earliest date

  3. Strategies for dereplication of natural compounds using high-resolution tandem mass spectrometry.

    Science.gov (United States)

    Kind, Tobias; Fiehn, Oliver

    2017-09-01

    Complete structural elucidation of natural products is commonly performed by nuclear magnetic resonance spectroscopy (NMR), but annotating compounds to most likely structures using high-resolution tandem mass spectrometry is a faster and feasible first step. The CASMI contest 2016 (Critical Assessment of Small Molecule Identification) provided spectra of eighteen compounds for the best manual structure identification in the natural products category. High resolution precursor and tandem mass spectra (MS/MS) were available to characterize the compounds. We used the Seven Golden Rules, Sirius2 and MS-FINDER software for determination of molecular formulas, and then we queried the formulas in different natural product databases including DNP, UNPD, ChemSpider and REAXYS to obtain molecular structures. We used different in-silico fragmentation tools including CFM-ID, CSI:FingerID and MS-FINDER to rank these compounds. Additional neutral losses and product ion peaks were manually investigated. This manual and time consuming approach allowed for the correct dereplication of thirteen of the eighteen natural products.

  4. A new processing scheme for ultra-high resolution direct infusion mass spectrometry data

    Science.gov (United States)

    Zielinski, Arthur T.; Kourtchev, Ivan; Bortolini, Claudio; Fuller, Stephen J.; Giorio, Chiara; Popoola, Olalekan A. M.; Bogialli, Sara; Tapparo, Andrea; Jones, Roderic L.; Kalberer, Markus

    2018-04-01

    High resolution, high accuracy mass spectrometry is widely used to characterise environmental or biological samples with highly complex composition enabling the identification of chemical composition of often unknown compounds. Despite instrumental advancements, the accurate molecular assignment of compounds acquired in high resolution mass spectra remains time consuming and requires automated algorithms, especially for samples covering a wide mass range and large numbers of compounds. A new processing scheme is introduced implementing filtering methods based on element assignment, instrumental error, and blank subtraction. Optional post-processing incorporates common ion selection across replicate measurements and shoulder ion removal. The scheme allows both positive and negative direct infusion electrospray ionisation (ESI) and atmospheric pressure photoionisation (APPI) acquisition with the same programs. An example application to atmospheric organic aerosol samples using an Orbitrap mass spectrometer is reported for both ionisation techniques resulting in final spectra with 0.8% and 8.4% of the peaks retained from the raw spectra for APPI positive and ESI negative acquisition, respectively.

  5. High-resolution gamma ray attenuation density measurements on mining exploration drill cores, including cut cores

    Science.gov (United States)

    Ross, P.-S.; Bourke, A.

    2017-01-01

    Physical property measurements are increasingly important in mining exploration. For density determinations on rocks, one method applicable on exploration drill cores relies on gamma ray attenuation. This non-destructive method is ideal because each measurement takes only 10 s, making it suitable for high-resolution logging. However calibration has been problematic. In this paper we present new empirical, site-specific correction equations for whole NQ and BQ cores. The corrections force back the gamma densities to the "true" values established by the immersion method. For the NQ core caliber, the density range extends to high values (massive pyrite, 5 g/cm3) and the correction is thought to be very robust. We also present additional empirical correction factors for cut cores which take into account the missing material. These "cut core correction factors", which are not site-specific, were established by making gamma density measurements on truncated aluminum cylinders of various residual thicknesses. Finally we show two examples of application for the Abitibi Greenstone Belt in Canada. The gamma ray attenuation measurement system is part of a multi-sensor core logger which also determines magnetic susceptibility, geochemistry and mineralogy on rock cores, and performs line-scan imaging.

  6. [Application of liquid chromatography-high resolution mass spectrometry in toxicological screening].

    Science.gov (United States)

    Li, Xiao-Wen; Shen, Bao-Hua; Zhuo, Xian-Yi

    2011-10-01

    Due to the diversity of toxicologically relevant substances, the uncertainty of target compounds and the specificity of samples, toxicological screening techniques have always been valued by the forensic toxicologists. Depending on its powerful separation ability, superhigh resolution and accurate mass measurement, combined with the two levels spectrum database matching and abundance ratio of isotope ion, the liquid chromatography-high resolution mass spectrometry (LC-HRMS) analyzers have increasingly advantage in screening and identification of chemical compound. This review focuses on the applications of LC-HRMS in screening and identification of drug-of-abuse, prescription drugs, pesticide and stimulant. The prospect of LC-HRMS in forensic toxicology analysis is also included.

  7. 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...

  8. Gamma spectrometry today

    International Nuclear Information System (INIS)

    Hemingway, J.

    1990-01-01

    This paper reviews the important advances in gamma spectroscopy made in recent years. Improvements in detectors and other components and the addition of on-line computer control systems is discussed. (UK)

  9. A clinical gamma camera-based pinhole collimated system for high resolution small animal SPECT imaging

    Energy Technology Data Exchange (ETDEWEB)

    Mejia, J.; Galvis-Alonso, O.Y., E-mail: mejia_famerp@yahoo.com.b [Faculdade de Medicina de Sao Jose do Rio Preto (FAMERP), SP (Brazil). Dept. de Biologia Molecular; Castro, A.A. de; Simoes, M.V. [Faculdade de Medicina de Sao Jose do Rio Preto (FAMERP), SP (Brazil). Dept. de Clinica Medica; Leite, J.P. [Universidade de Sao Paulo (FMRP/USP), Ribeirao Preto, SP (Brazil). Fac. de Medicina. Dept. de Neurociencias e Ciencias do Comportamento; Braga, J. [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos, SP (Brazil). Div. de Astrofisica

    2010-11-15

    The main objective of the present study was to upgrade a clinical gamma camera to obtain high resolution tomographic images of small animal organs. The system is based on a clinical gamma camera to which we have adapted a special-purpose pinhole collimator and a device for positioning and rotating the target based on a computer-controlled step motor. We developed a software tool to reconstruct the target's three-dimensional distribution of emission from a set of planar projections, based on the maximum likelihood algorithm. We present details on the hardware and software implementation. We imaged phantoms and heart and kidneys of rats. When using pinhole collimators, the spatial resolution and sensitivity of the imaging system depend on parameters such as the detector-to-collimator and detector-to-target distances and pinhole diameter. In this study, we reached an object voxel size of 0.6 mm and spatial resolution better than 2.4 and 1.7 mm full width at half maximum when 1.5- and 1.0-mm diameter pinholes were used, respectively. Appropriate sensitivity to study the target of interest was attained in both cases. Additionally, we show that as few as 12 projections are sufficient to attain good quality reconstructions, a result that implies a significant reduction of acquisition time and opens the possibility for radiotracer dynamic studies. In conclusion, a high resolution single photon emission computed tomography (SPECT) system was developed using a commercial clinical gamma camera, allowing the acquisition of detailed volumetric images of small animal organs. This type of system has important implications for research areas such as Cardiology, Neurology or Oncology. (author)

  10. Investigation of drift gas selectivity in high resolution ion mobility spectrometry with mass spectrometry detection.

    Science.gov (United States)

    Matz, Laura M; Hill, Herbert H; Beegle, Luther W; Kanik, Isik

    2002-04-01

    Recent studies in electrospray ionization (ESI)/ion mobility spectrometry (IMS) have focussed on employing different drift gases to alter separation efficiency for some molecules. This study investigates four structurally similar classes of molecules (cocaine and metabolites, amphetamines, benzodiazepines, and small peptides) to determine the effect of structure on relative mobility changes in four drift gases (helium, nitrogen, argon, carbon dioxide). Collision cross sections were plotted against drift gas polarizability and a linear relationship was found for the nineteen compounds evaluated in the study. Based on the reduced mobility database, all nineteen compounds could be separated in one of the four drift gases, however, the drift gas that provided optimal separation was specific for the two compounds.

  11. A micro-machined retro-reflector for improving light yield in ultra-high-resolution gamma cameras

    NARCIS (Netherlands)

    Heemskerk, J.W.T.; Korevaar, M.A.N.; Kreuger, R.; Ligtvoet, C.M.; Schotanus, P.; Beekman, F.J.

    2009-01-01

    High-resolution imaging of x-ray and gamma-ray distributions can be achieved with cameras that use charge coupled devices (CCDs) for detecting scintillation light flashes. The energy and interaction position of individual gamma photons can be determined by rapid processing of CCD images of

  12. High-resolution continuum-source atomic absorption spectrometry: what can we expect?

    Directory of Open Access Journals (Sweden)

    Welz Bernhard

    2003-01-01

    Full Text Available A new instrumental concept has been developed for atomic absorption spectrometry (AAS, using a high-intensity xenon short-arc lamp as continuum radiation source, a high-resolution double-echelle monochromator and a CCD array detector, providing a resolution of ~2 pm per pixel. Among the major advantages of the system are: i an improved signal-to-noise ratio because of the high intensity of the radiation source, resulting in improved photometric precision and detection limits; ii for the same reason, there are no more 'weak' lines, i.e. secondary lines can be used without compromises; iii new elements might be determined, for which no radiation source has been available; iv the entire spectral environment around the analytical line becomes 'visible', giving a lot more information than current AAS instruments; v the CCD array detector allows a truly simultaneous background correction close to the analytical line; vi the software is capable of storing reference spectra, e.g. of a molecular absorption with rotational fine structure, and of subtracting such spectra from the spectra recorded for a sample, using a least squares algorithm; vii although not yet realized, the system makes possible a truly simultaneous multi-element AAS measurement when an appropriate two-dimensional detector is used, as is already common practice in optical emission spectrometry; vii preliminary experiments have indicated that the instrumental concept could result in a more rugged analytical performance in the determination of trace elements in complex matrices.

  13. Fast-ion energy resolution by one-step reaction gamma-ray spectrometry

    DEFF Research Database (Denmark)

    Salewski, Mirko; Nocente, M.; Gorini, G.

    2016-01-01

    The spectral broadening of γ-rays from fusion plasmas can be measured in high-resolution gamma-ray spectrometry (GRS). We derive weight functions that determine the observable velocity space and quantify the velocity-space sensitivity of one-step reaction high-resolution GRS measurements in magne...

  14. The Generalized Gamma-DBN for High-Resolution SAR Image Classification

    Directory of Open Access Journals (Sweden)

    Zhiqiang Zhao

    2018-06-01

    Full Text Available With the increase of resolution, effective characterization of synthetic aperture radar (SAR image becomes one of the most critical problems in many earth observation applications. Inspired by deep learning and probability mixture models, a generalized Gamma deep belief network (g Γ-DBN is proposed for SAR image statistical modeling and land-cover classification in this work. Specifically, a generalized Gamma-Bernoulli restricted Boltzmann machine (gΓB-RBM is proposed to capture high-order statistical characterizes from SAR images after introducing the generalized Gamma distribution. After stacking the g Γ B-RBM and several standard binary RBMs in a hierarchical manner, a gΓ-DBN is constructed to learn high-level representation of different SAR land-covers. Finally, a discriminative neural network is constructed by adding an additional predict layer for different land-covers over the constructed deep structure. Performance of the proposed approach is evaluated via several experiments on some high-resolution SAR image patch sets and two large-scale scenes which are captured by ALOS PALSAR-2 and COSMO-SkyMed satellites respectively.

  15. 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)

  16. High-Resolution Gamma-Ray Imaging Measurements Using Externally Segmented Germanium Detectors

    Science.gov (United States)

    Callas, J.; Mahoney, W.; Skelton, R.; Varnell, L.; Wheaton, W.

    1994-01-01

    Fully two-dimensional gamma-ray imaging with simultaneous high-resolution spectroscopy has been demonstrated using an externally segmented germanium sensor. The system employs a single high-purity coaxial detector with its outer electrode segmented into 5 distinct charge collection regions and a lead coded aperture with a uniformly redundant array (URA) pattern. A series of one-dimensional responses was collected around 511 keV while the system was rotated in steps through 180 degrees. A non-negative, linear least-squares algorithm was then employed to reconstruct a 2-dimensional image. Corrections for multiple scattering in the detector, and the finite distance of source and detector are made in the reconstruction process.

  17. Automatic gamma spectrometry analytical apparatus

    International Nuclear Information System (INIS)

    Lamargot, J.-P.; Wanin, Maurice.

    1980-01-01

    This invention falls within the area of quantitative or semi-quantitative analysis by gamma spectrometry and particularly refers to a device for bringing the samples into the counting position. The purpose of this invention is precisely to provide an automatic apparatus specifically adapted to the analysis of hard gamma radiations. To this effect, the invention relates to a gamma spectrometry analytical device comprising a lead containment, a detector of which the sensitive part is located inside the containment and additionally comprising a transfer system for bringing the analyzed samples in succession to a counting position inside the containment above the detector. A feed compartment enables the samples to be brought in turn one by one on to the transfer system through a duct connecting the compartment to the transfer system. Sequential systems for the coordinated forward feed of the samples in the compartment and the transfer system complete this device [fr

  18. In-depth glycoproteomic characterization of γ-conglutin by high-resolution accurate mass spectrometry.

    Directory of Open Access Journals (Sweden)

    Silvia Schiarea

    Full Text Available The molecular characterization of bioactive food components is necessary for understanding the mechanisms of their beneficial or detrimental effects on human health. This study focused on γ-conglutin, a well-known lupin seed N-glycoprotein with health-promoting properties and controversial allergenic potential. Given the importance of N-glycosylation for the functional and structural characteristics of proteins, we studied the purified protein by a mass spectrometry-based glycoproteomic approach able to identify the structure, micro-heterogeneity and attachment site of the bound N-glycan(s, and to provide extensive coverage of the protein sequence. The peptide/N-glycopeptide mixtures generated by enzymatic digestion (with or without N-deglycosylation were analyzed by high-resolution accurate mass liquid chromatography-multi-stage mass spectrometry. The four main micro-heterogeneous variants of the single N-glycan bound to γ-conglutin were identified as Man2(Xyl (Fuc GlcNAc2, Man3(Xyl (Fuc GlcNAc2, GlcNAcMan3(Xyl (Fuc GlcNAc2 and GlcNAc 2Man3(Xyl (Fuc GlcNAc2. These carry both core β1,2-xylose and core α1-3-fucose (well known Cross-Reactive Carbohydrate Determinants, but corresponding fucose-free variants were also identified as minor components. The N-glycan was proven to reside on Asn131, one of the two potential N-glycosylation sites. The extensive coverage of the γ-conglutin amino acid sequence suggested three alternative N-termini of the small subunit, that were later confirmed by direct-infusion Orbitrap mass spectrometry analysis of the intact subunit.

  19. Assessment of meat authenticity using bioinformatics, targeted peptide biomarkers and high-resolution mass spectrometry.

    Science.gov (United States)

    Ruiz Orduna, Alberto; Husby, Erik; Yang, Charles T; Ghosh, Dipankar; Beaudry, Francis

    2015-01-01

    In recent years a significant increase of food fraud has been observed, ranging from false label claims to the use of additives and fillers to increase profitability. Recently in 2013 horse and pig DNAs were detected in beef products sold from several retailers. Mass spectrometry (MS) has become the workhorse in protein research, and the detection of marker proteins could serve for both animal species and tissue authentication. Meat species authenticity is performed in this paper using a well-defined proteogenomic annotation, carefully chosen surrogate tryptic peptides and analysis using a hybrid quadrupole-Orbitrap MS. Selected mammalian meat samples were homogenised and proteins were extracted and digested with trypsin. The samples were analysed using a high-resolution MS. Chromatography was achieved using a 30-min linear gradient along with a BioBasic C8 100 × 1 mm column at a flow rate of 75 µl min(-1). The MS was operated in full-scan high resolution and accurate mass. MS/MS spectra were collected for selected proteotypic peptides. Muscular proteins were methodically analysed in silico in order to generate tryptic peptide mass lists and theoretical MS/MS spectra. Following a comprehensive bottom-up proteomic analysis, we detected and identified a proteotypic myoglobin tryptic peptide (120-134) for each species with observed m/z below 1.3 ppm compared with theoretical values. Moreover, proteotypic peptides from myosin-1, myosin-2 and β-haemoglobin were also identified. This targeted method allowed comprehensive meat speciation down to 1% (w/w) of undesired product.

  20. Atmospheric Oxidation of Squalene: Molecular Study Using COBRA Modeling and High-Resolution Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Fooshee, David R.; Aiona, Paige K.; Laskin, Alexander; Laskin, Julia; Nizkorodov, Sergey; Baldi, Pierre

    2015-10-22

    Squalene is a major component of skin and plant surface lipids, and is known to be present at high concentrations in indoor dust. Its high reactivity toward ozone makes it an important ozone sink and a natural protectant against atmospheric oxidizing agents. While the volatile products of squalene ozonolysis are known, the condensed-phase products have not been characterized. We present an analysis of condensed-phase products resulting from an extensive oxidation of squalene by ozone probed by electrospray ionization (ESI) high-resolution mass spectrometry (HR-MS). A complex distribution of nearly 1,300 peaks assignable to molecular formulas is observed in direct infusion positive ion mode ESI mass spectra. The distribution of peaks in the mass spectra suggests that there are extensive cross-coupling reactions between hydroxy-carbonyl products of squalene ozonolysis. To get additional insights into the mechanism, we apply a Computational Brewing Application (COBRA) to simulate the oxidation of squalene in the presence of ozone, and compare predicted results with those observed by the HR-MS experiments. The system predicts over one billion molecular structures between 0-1450 Da, which correspond to about 27,000 distinct elemental formulas. Over 83% of the squalene oxidation products inferred from the mass spectrometry data are matched by the simulation. Simulation indicates a prevalence of peroxy groups, with hydroxyl and ether groups being the second-most important O-containing functional groups formed during squalene oxidation. These highly oxidized products of squalene ozonolysis may accumulate on indoor dust and surfaces, and contribute to their redox capacity.

  1. Indexing Permafrost Soil Organic Matter Degradation Using High-Resolution Mass Spectrometry.

    Science.gov (United States)

    Mann, Benjamin F; Chen, Hongmei; Herndon, Elizabeth M; Chu, Rosalie K; Tolic, Nikola; Portier, Evan F; Roy Chowdhury, Taniya; Robinson, Errol W; Callister, Stephen J; Wullschleger, Stan D; Graham, David E; Liang, Liyuan; Gu, Baohua

    2015-01-01

    Microbial degradation of soil organic matter (SOM) is a key process for terrestrial carbon cycling, although the molecular details of these transformations remain unclear. This study reports the application of ultrahigh resolution mass spectrometry to profile the molecular composition of SOM and its degradation during a simulated warming experiment. A soil sample, collected near Barrow, Alaska, USA, was subjected to a 40-day incubation under anoxic conditions and analyzed before and after the incubation to determine changes of SOM composition. A CHO index based on molecular C, H, and O data was utilized to codify SOM components according to their observed degradation potentials. Compounds with a CHO index score between -1 and 0 in a water-soluble fraction (WSF) demonstrated high degradation potential, with a highest shift of CHO index occurred in the N-containing group of compounds, while similar stoichiometries in a base-soluble fraction (BSF) did not. Additionally, compared with the classical H:C vs O:C van Krevelen diagram, CHO index allowed for direct visualization of the distribution of heteroatoms such as N in the identified SOM compounds. We demonstrate that CHO index is useful not only in characterizing arctic SOM at the molecular level but also enabling quantitative description of SOM degradation, thereby facilitating incorporation of the high resolution MS datasets to future mechanistic models of SOM degradation and prediction of greenhouse gas emissions.

  2. Advances in high-resolution mass spectrometry based on metabolomics studies for food--a review.

    Science.gov (United States)

    Rubert, Josep; Zachariasova, Milena; Hajslova, Jana

    2015-01-01

    Food authenticity becomes a necessity for global food policies, since food placed in the market without fail has to be authentic. It has always been a challenge, since in the past minor components, called also markers, have been mainly monitored by chromatographic methods in order to authenticate the food. Nevertheless, nowadays, advanced analytical methods have allowed food fingerprints to be achieved. At the same time they have been also combined with chemometrics, which uses statistical methods in order to verify food and to provide maximum information by analysing chemical data. These sophisticated methods based on different separation techniques or stand alone have been recently coupled to high-resolution mass spectrometry (HRMS) in order to verify the authenticity of food. The new generation of HRMS detectors have experienced significant advances in resolving power, sensitivity, robustness, extended dynamic range, easier mass calibration and tandem mass capabilities, making HRMS more attractive and useful to the food metabolomics community, therefore becoming a reliable tool for food authenticity. The purpose of this review is to summarise and describe the most recent metabolomics approaches in the area of food metabolomics, and to discuss the strengths and drawbacks of the HRMS analytical platforms combined with chemometrics.

  3. Metabolite profiling of carbamazepine and ibuprofen in Solea senegalensis bile using high-resolution mass spectrometry.

    Science.gov (United States)

    Aceña, Jaume; Pérez, Sandra; Eichhorn, Peter; Solé, Montserrat; Barceló, Damià

    2017-09-01

    The widespread occurrence of pharmaceuticals in the aquatic environment has raised concerns about potential adverse effects on exposed wildlife. Very little is currently known on exposure levels and clearance mechanisms of drugs in marine fish. Within this context, our research was focused on the identification of main metabolic reactions, generated metabolites, and caused effects after exposure of fish to carbamazepine (CBZ) and ibuprofen (IBU). To this end, juveniles of Solea senegalensis acclimated to two temperature regimes of 15 and 20 °C for 60 days received a single intraperitoneal dose of these drugs. A control group was administered the vehicle (sunflower oil). Bile samples were analyzed by ultra-high-performance liquid chromatography-high-resolution mass spectrometry on a Q Exactive (Orbitrap) system, allowing to propose plausible identities for 11 metabolites of CBZ and 13 metabolites of IBU in fish bile. In case of CBZ metabolites originated from aromatic and benzylic hydroxylation, epoxidation, and ensuing O-glucuronidation, O-methylation of a catechol-like metabolite was also postulated. Ibuprofen, in turn, formed multiple hydroxyl metabolites, O-glucuronides, and (hydroxyl)-acyl glucuronides, in addition to several taurine conjugates. Enzymatic responses after drug exposures revealed a water temperature-dependent induction of microsomal carboxylesterases. The metabolite profiling in fish bile provides an important tool for pharmaceutical exposure assessment. Graphical abstract Studies of metabolism of carbamazepine and ibuprofen in fish.

  4. Investigation of phosphorus atomization using high-resolution continuum source electrothermal atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Dessuy, Morgana B.; Vale, Maria Goreti R.; Lepri, Fabio G.; Welz, Bernhard; Heitmann, Uwe

    2007-01-01

    The atomization of phosphorus in electrothermal atomic absorption spectrometry has been investigated using a high-resolution continuum source atomic absorption spectrometer and atomization from a graphite platform as well as from a tantalum boat inserted in a graphite tube. A two-step atomization mechanism is proposed for phosphorus, where the first step is a thermal dissociation, resulting in a fast atomization signal early in the atomization stage, and the second step is a slow release of phosphorus atoms from the graphite tube surface following the adsorption of molecular phosphorus at active sites of the graphite surface. Depending on experimental conditions only one of the mechanisms or both might be active. In the absence of a modifier and with atomization from a graphite or tantalum platform the second mechanism appears to be dominant, whereas in the presence of sodium fluoride as a modifier both mechanisms are observed. Intercalation of phosphorus into the graphite platform in the condensed phase has also been observed; this phosphorus, however, appears to be permanently trapped in the structure of the graphite and does not contribute to the absorption signal

  5. The EPA iCSS Chemistry Dashboard to Support Compound Identification Using High Resolution Mass Spectrometry Data (ACS Fall meeting)

    Science.gov (United States)

    Abstract: There is a growing need for rapid chemical screening and prioritization to inform regulatory decision-making on thousands of chemicals in the environment. We have previously used high-resolution mass spectrometry to examine household vacuum dust samples using liquid chr...

  6. Environmental Chemistry Compound Identification Using High Resolution Mass Spectrometry Data Integrated to the EPA Chemistry Dashboard (EAS)

    Science.gov (United States)

    There is a growing need for rapid chemical screening and prioritization to inform regulatory decision-making on thousands of chemicals in the environment. We have previously used high-resolution mass spectrometry to examine household vacuum dust samples using liquid chromatograph...

  7. Screening of plant toxins in food,feed and botanicals using full-scan high-resolution (Orbitrap) mass spectrometry

    NARCIS (Netherlands)

    Mol, J.G.J.; Dam, van R.C.J.; Zomer, P.; Mulder, P.P.J.

    2011-01-01

    A generic method based on LC with full-scan high-resolution (Orbitrap) mass spectrometry (MS) was systematically investigated for the simultaneous detection of a wide range of plant toxins in a variety of food and feed matrices. For a selection of 150 substances, representing various chemical

  8. Targeted metabolite profile of food bioactive compounds by Orbitrap high resolution mass spectrometry: The 'FancyTiles' approach

    NARCIS (Netherlands)

    Troise, A.D.; Ferracane, R.; Palermo, M.; Fogliano, V.

    2014-01-01

    In this paper a new targeted metabolic profile approach using Orbitrap high resolution mass spectrometry was described. For each foodmatrix various classes of bioactive compounds and some specificmetabolites of interest were selected on the basis of the existing knowledge creating an easy-to-read

  9. 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

  10. 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

  11. Gamma spectrometry of infinite 4Π geometry

    International Nuclear Information System (INIS)

    Nordemann, D.J.R.

    1987-07-01

    Owing to the weak absorption og gamma radiation by matter, gamma-ray spectrometry may be applied to samples of great volume. A very interesting case is that of the gamma-ray spectrometry applied with 4Π geometry around the detector on a sample assumed to be of infinite extension. The determination of suitable efficiencies allows this method to be quantitative. (author) [pt

  12. SAMPO 90 - High resolution interactive gamma spectrum analysis including automation with macros

    International Nuclear Information System (INIS)

    Aarnio, P.A.; Nikkinen, M.T.; Routti, J.T.

    1991-01-01

    SAMPO 90 is a high performance gamma spectrum analysis program for personal computers. It uses high resolution color graphics to display calibrations, spectra, fitting results as multiplet components, and analysis results. All the analysis phases can be done either under full interactive user control or by using macros for automated measurement and analysis sequences including the control of MCAs and sample changers. Semi-automated calibrations for peak shapes (Gaussian with exponential tails), detector efficiency, and energy are available with a possibility for user intervention through interactive graphics. Accurate peak area determination of even the most complex multiplets, of up to 32 components, is accomplished using linear, non-linear and mixed mode fitting, where the component energies and areas can be either frozen or allowed to float in arbitrary combinations. Nuclide identification is done using associated lines techniques which allow interference correction for fully overlapping peaks. Peaked Background Subtraction can be performed and Minimum Detectable Activities calculated. Attenuation corrections can be taken into account in detector efficiency calculation. The most common PC-based MCA spectrum formats (Canberra S100, Ortec ACE, Nucleus PCA, ND AccuSpec) are supported as well as ASCII spectrum files. A gamma-line library is included together with an editor for user configurable libraries. The analysis reports and program parameters are fully customizable. Function key macros can be used to automate the most common analysis procedures. Small batch type modules are additionally available for routine work. SAMPO 90 is a result of over twenty man years of programming and contains 25,000 lines of Fortran, 10,000 lines of C, and 12,000 lines of assembler

  13. Determination of Polychlorinated Diben-p-dioxins and Dibenzofurans in Flue Gas by High Resolution Gas Chromatography Coupled with High Resolution Spectrometry

    International Nuclear Information System (INIS)

    Chen, T.; Yan, J. H.; Li, X. D.; Cen, K. F.

    2007-01-01

    In 1988 the first municipal solid waste (MSW) incinerator plant was built in Shenzhen, China. Since then Beijing, Shanghai and other big cities have built a few MSW incineration plants. MSW incineration has gradually been used in some cities of China due to its advantages such as significant volume reduction (about 90%), mass reduction (about 70%), and toxicity reduction of the waste and energy recovery. However, MSW incineration is sometimes considered to the general public as the secondary pollution source, because of concerns about is toxic combustion byproducts (TCBs). Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) are the most toxic compounds among the TCBs. In this paper, PCDD/Fs in flue gas produced from a MSW incinerator were isokinetically withdrawn and collected in a multi component sampling train. Then the PCDD/Fs samples were extracted, concentrated and cleaned up step by step. Finally, the determination of PCDD/Fs was carried out by high-resolution gas chromatography coupled with high-resolution mass spectrometry (HRGC/HRMS). The two PCDD/Fs emission levels were the similar, which was 0.115 and 0.096ng TEQ/Nm3 although different sampling time. The PCDD/Fs emission levels were lower than the PCDD/Fs emission regulation in China (1.0 ng TEQ / Nm3) and close to the developed countries' regulations, i.e., 0.1ng TEQ/Nm3. 2,3,4,7,8-Pentachlorodibenzofuran (2,3,4,7,8-PeCDF) was the dominant congener of the total TEQ

  14. High resolution gamma-ray spectroscopy and the fascinating angular momentum realm of the atomic nucleus

    International Nuclear Information System (INIS)

    Riley, M A; Simpson, J; Paul, E S

    2016-01-01

    In 1974 Aage Bohr and Ben Mottelson predicted the different ‘phases’ that may be expected in deformed nuclei as a function of increasing angular momentum and excitation energy all the way up to the fission limit. While admitting their picture was highly conjectural they confidently stated ‘...with the ingenious experimental approaches that are being developed, we may look forward with excitement to the detailed spectroscopic studies that will illuminate the behaviour of the spinning quantised nucleus’ . High resolution gamma-ray spectroscopy has indeed been a major tool in studying the structure of atomic nuclei and has witnessed numerous significant advances over the last four decades. This article will select highlights from investigations at the Niels Bohr Institute, Denmark, and Daresbury Laboratory, UK, in the late 1970s and early 1980s, some of which have continued at other national laboratories in Europe and the USA to the present day. These studies illustrate the remarkable diversity of phenomena and symmetries exhibited by nuclei in the angular momentum–excitation energy plane that continue to surprise and fascinate scientists. (invited comment)

  15. Multi-dimensional analysis of high resolution {gamma}-ray data

    Energy Technology Data Exchange (ETDEWEB)

    Flibotte, S; Huttmeier, U J; France, G de; Haas, B; Romain, P; Theisen, Ch; Vivien, J P; Zen, J [Centre National de la Recherche Scientifique (CNRS), 67 - Strasbourg (France); Bednarczyk, P [Institute of Nuclear Physics, Cracow (Poland)

    1992-08-01

    High resolution {gamma}-ray multi-detectors capable of measuring high-fold coincidences with a large efficiency are presently under construction (EUROGAM, GASP, GAMMASPHERE). The future experimental progress in our understanding of nuclear structure at high spin critically depends on our ability to analyze the data in a multi-dimensional space and to resolve small photopeaks of interest from the generally large background. Development of programs to process such high-fold events is still in its infancy and only the 3-fold case has been treated so far. As a contribution to the software development associated with the EUROGAM spectrometer, we have written and tested the performances of computer codes designed to select multi-dimensional gates from 3-, 4- and 5-fold coincidence databases. The tests were performed on events generated with a Monte Carlo simulation and also on experimental data (triples) recorded with the 8{pi} spectrometer and with a preliminary version of the EUROGAM array. (author). 7 refs., 3 tabs., 1 fig.

  16. High resolution gamma-ray spectroscopy and the fascinating angular momentum realm of the atomic nucleus

    Science.gov (United States)

    Riley, M. A.; Simpson, J.; Paul, E. S.

    2016-12-01

    In 1974 Aage Bohr and Ben Mottelson predicted the different ‘phases’ that may be expected in deformed nuclei as a function of increasing angular momentum and excitation energy all the way up to the fission limit. While admitting their picture was highly conjectural they confidently stated ‘...with the ingenious experimental approaches that are being developed, we may look forward with excitement to the detailed spectroscopic studies that will illuminate the behaviour of the spinning quantised nucleus’. High resolution gamma-ray spectroscopy has indeed been a major tool in studying the structure of atomic nuclei and has witnessed numerous significant advances over the last four decades. This article will select highlights from investigations at the Niels Bohr Institute, Denmark, and Daresbury Laboratory, UK, in the late 1970s and early 1980s, some of which have continued at other national laboratories in Europe and the USA to the present day. These studies illustrate the remarkable diversity of phenomena and symmetries exhibited by nuclei in the angular momentum-excitation energy plane that continue to surprise and fascinate scientists.

  17. Non-targeted glycosidic profiling of international wines using neutral loss-high resolution mass spectrometry.

    Science.gov (United States)

    Barnaba, C; Dellacassa, E; Nicolini, G; Nardin, T; Serra, M; Larcher, R

    2018-07-06

    Many metabolites naturally occur as glycosides, since sugar moieties can be crucial for their biological activity and increase their water solubility. In the plant kingdom they may occur as glycosides or sugar esters, depending on precursor chemical structure, and in wine they have traditionally attracted attention due to their organoleptic properties, such as astringency and bitterness, and because they affect the colour and aroma of wines. A new approach directed at detailed description of glycosides in a large selection of monovarietal wines (8 samples each of Pinot Blanc, Muller Thurgau, Riesling, Traminer, Merlot, Pinot Noir and Cabernet Sauvignon) was developed by combining high performance liquid chromatography with high resolution tandem mass spectrometry. Analytical separation was performed on an Accucore™ Polar Premium LC column, while mass analysis was performed in negative ion mode with an non-targeted screening approach, using a Full MS/AIF/NL dd-MS 2 experiment at a resolving power of 140,000 FWHM. Over 280 glycoside-like compounds were detected, of which 133 (including low-molecular weight phenols, flavonoids and monoterpenols) were tentatively identified in the form of pentose (6), deoxyhexose (17), hexose (73), hexose-pentose (16), hexose-deoxyhexose (7), dihexose (5) and hexose ester (9) derivatives. It was not possible to univocally define the corresponding chemical structure for the remaining 149 glycosides. Non-parametric statistical analysis showed it was possible to well characterise the glycosylated profile of all red and Traminer wines, while the identified glycosides were almost entirely lacking in Pinot Blanc, Riesling and Muller Thurgau wines. Also Tukey's Honestly Significant Difference test (p wines from each other according to their glycosylated profile. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. Similarity of High-Resolution Tandem Mass Spectrometry Spectra of Structurally Related Micropollutants and Transformation Products

    Science.gov (United States)

    Schollée, Jennifer E.; Schymanski, Emma L.; Stravs, Michael A.; Gulde, Rebekka; Thomaidis, Nikolaos S.; Hollender, Juliane

    2017-12-01

    High-resolution tandem mass spectrometry (HRMS2) with electrospray ionization is frequently applied to study polar organic molecules such as micropollutants. Fragmentation provides structural information to confirm structures of known compounds or propose structures of unknown compounds. Similarity of HRMS2 spectra between structurally related compounds has been suggested to facilitate identification of unknown compounds. To test this hypothesis, the similarity of reference standard HRMS2 spectra was calculated for 243 pairs of micropollutants and their structurally related transformation products (TPs); for comparison, spectral similarity was also calculated for 219 pairs of unrelated compounds. Spectra were measured on Orbitrap and QTOF mass spectrometers and similarity was calculated with the dot product. The influence of different factors on spectral similarity [e.g., normalized collision energy (NCE), merging fragments from all NCEs, and shifting fragments by the mass difference of the pair] was considered. Spectral similarity increased at higher NCEs and highest similarity scores for related pairs were obtained with merged spectra including measured fragments and shifted fragments. Removal of the monoisotopic peak was critical to reduce false positives. Using a spectral similarity score threshold of 0.52, 40% of related pairs and 0% of unrelated pairs were above this value. Structural similarity was estimated with the Tanimoto coefficient and pairs with higher structural similarity generally had higher spectral similarity. Pairs where one or both compounds contained heteroatoms such as sulfur often resulted in dissimilar spectra. This work demonstrates that HRMS2 spectral similarity may indicate structural similarity and that spectral similarity can be used in the future to screen complex samples for related compounds such as micropollutants and TPs, assisting in the prioritization of non-target compounds. [Figure not available: see fulltext.

  19. Characterization of Fumonisin A-Series by High-Resolution Liquid Chromatography-Orbitrap Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Masayoshi Tamura

    2014-08-01

    Full Text Available Fumonisin A-series (FAs in a reference material of corn sample that was naturally contaminated with fumonisins was characterized using high-resolution liquid chromatography-Orbitrap mass spectrometry (LC-Orbitap MS. Peaks for fumonisin B1 (FB1, fumonisin B2 (FB2, and fumonisin B3 (FB3, in addition to three peaks corresponding to unknown compounds I, II, and III, were detected in the chromatogram for the corn sample. Fragment ion analysis for FB1, FB2, and FB3 showed that while the ions formed at m/z values of 200–800 were similar to those formed by the cleavage of the tricarballylic acids and the hydroxyl groups, the fragmentation patterns at m/z values of 50–200 varied depending on the hydroxyl group locations in the compounds. Fragment ion analysis of compounds I–III revealed structural similarities to FBs, only differing by an additional C2H2O in the unknown compounds. Using these results and by comparing the product ion mass spectra of compound I with fumonisin A1 (FA1 synthesized from FB1 standards, compounds I–III were hypothesized to be N-acetyl analogs of FBs: fumonisins A1 (FA1, A2 (FA2, and A3 (FA3. The method for determining concentrations was validated with FA1, FB1, FB2, and FB3 standards and applied to analyze the reference material. The FB1, FB2, and FB3 analytical levels were within acceptance limits and the amount of FA1 in the material was ~15% of FB1 amount at 4.2 mg/kg.

  20. Characterization of fumonisin A-series by high-resolution liquid chromatography-orbitrap mass spectrometry.

    Science.gov (United States)

    Tamura, Masayoshi; Mochizuki, Naoki; Nagatomi, Yasushi; Toriba, Akira; Hayakawa, Kazuichi

    2014-08-21

    Fumonisin A-series (FAs) in a reference material of corn sample that was naturally contaminated with fumonisins was characterized using high-resolution liquid chromatography-Orbitrap mass spectrometry (LC-Orbitap MS). Peaks for fumonisin B1 (FB1), fumonisin B2 (FB2), and fumonisin B3 (FB3), in addition to three peaks corresponding to unknown compounds I, II, and III, were detected in the chromatogram for the corn sample. Fragment ion analysis for FB1, FB2, and FB3 showed that while the ions formed at m/z values of 200-800 were similar to those formed by the cleavage of the tricarballylic acids and the hydroxyl groups, the fragmentation patterns at m/z values of 50-200 varied depending on the hydroxyl group locations in the compounds. Fragment ion analysis of compounds I-III revealed structural similarities to FBs, only differing by an additional C2H2O in the unknown compounds. Using these results and by comparing the product ion mass spectra of compound I with fumonisin A1 (FA1) synthesized from FB1 standards, compounds I-III were hypothesized to be N-acetyl analogs of FBs: fumonisins A1 (FA1), A2 (FA2), and A3 (FA3). The method for determining concentrations was validated with FA1, FB1, FB2, and FB3 standards and applied to analyze the reference material. The FB1, FB2, and FB3 analytical levels were within acceptance limits and the amount of FA1 in the material was ~15% of FB1 amount at 4.2 mg/kg.

  1. Determination of sulfur in food by high resolution continuum source flame molecular absorption spectrometry

    Science.gov (United States)

    Zambrzycka, Elżbieta; Godlewska-Żyłkiewicz, Beata

    2014-11-01

    In the present work, a fast, simple and sensitive analytical method for determination of sulfur in food and beverages by high resolution continuum source flame molecular absorption spectrometry was developed. The determination was performed via molecular absorption of carbon monosulfide, CS. Different CS rotational lines (257.959 nm, 258.033 nm, 258.055 nm), number of pixels and types of standard solution of sulfur, namely: sulfuric acid, sodium sulfate, ammonium sulfate, sodium sulfite, sodium sulfide, DL-cysteine, and L-cystine, were studied in terms of sensitivity, repeatability of results as well as limit of detection and limit of quantification. The best results were obtained for measurements of absorption of the CS molecule at 258.055 nm at the wavelength range covering 3 pixels and DL-cysteine in 0.2 mol L- 1 HNO3 solution as a calibration standard. Under optimized conditions the limit of detection and the limit of quantification achieved for sulfur were 10.9 mg L- 1 and 36.4 mg L- 1, respectively. The repeatability of the results expressed as relative standard deviation was typically beverage samples with added known amount of sulfur standard. The recovery of analyte from such samples was in the range of 93-105% with the repeatability in the range of 4.1-5.0%. The developed method was applied for the determination of sulfur in milk (194 ± 10 mg kg- 1), egg white (2188 ± 29 mg kg- 1), mineral water (31.0 ± 0.9 mg L- 1), white wine (260 ± 4 mg L- 1) and red wine (82 ± 2 mg L- 1), as well as in sample rich in ions, such as bitter mineral water (6900 ± 100 mg L- 1).

  2. MASH Suite: a user-friendly and versatile software interface for high-resolution mass spectrometry data interpretation and visualization.

    Science.gov (United States)

    Guner, Huseyin; Close, Patrick L; Cai, Wenxuan; Zhang, Han; Peng, Ying; Gregorich, Zachery R; Ge, Ying

    2014-03-01

    The rapid advancements in mass spectrometry (MS) instrumentation, particularly in Fourier transform (FT) MS, have made the acquisition of high-resolution and high-accuracy mass measurements routine. However, the software tools for the interpretation of high-resolution MS data are underdeveloped. Although several algorithms for the automatic processing of high-resolution MS data are available, there is still an urgent need for a user-friendly interface with functions that allow users to visualize and validate the computational output. Therefore, we have developed MASH Suite, a user-friendly and versatile software interface for processing high-resolution MS data. MASH Suite contains a wide range of features that allow users to easily navigate through data analysis, visualize complex high-resolution MS data, and manually validate automatically processed results. Furthermore, it provides easy, fast, and reliable interpretation of top-down, middle-down, and bottom-up MS data. MASH Suite is convenient, easily operated, and freely available. It can greatly facilitate the comprehensive interpretation and validation of high-resolution MS data with high accuracy and reliability.

  3. Efficient high-resolution X-ray emission spectrometry using synchrotron radiation

    International Nuclear Information System (INIS)

    Unterumsberger, Rainer

    2015-01-01

    The aim of the present work is to get access to high-resolution X-Ray Emission Spectrometry (XES) at nanoscaled materials, consisting of light elements and transition metals, by the increase of the sensitivity of a Wavelength-Dispersive Spectrometer (WDS) in the soft X-Ray range. The increase of the sensitivity was achieved by a refocusing of the incident radiation. With the increased sensitivity of the WDS, it was possible to determine the chemical species of different, nominal 100 nm thin titanium oxides. The combination of the refocusing optic and calibrated spectrometer enabled the detection and deconvolution of the L-fluorescence radiation of these nanoscaled titanium oxides. Due to the calibration of the spectrometer, a reliable determination of the transition probabilities of the titanium La- and Ll-fluorescence lines as a function of the chemical state is possible. To the best of my knowledge, the determination of the transition probabilities as a function of the chemical state in the soft X-Ray range has not been investigated yet. The quality of the refocusing was characterized using different diagnostic tools. Vertical full width at half maximum (FWHM) values of the focused beam between 10 μm to 20 μm and horizontal FWHM values between 12 μm and 25 μm could be achieved over an energy range of 180 eV to 1310 eV. Using calibrated photodiodes, it was possible to determine the absolute transmission of the used single bounce monocapillary as well as to monitor the absolute photon flux. By means of the refocusing, it was possible to increase the photon flux by a factor of 4.9 experimentally. The increase of the photon flux enables the analysis of nanoscaled materials with the used spectrometer. This could be shown based on the determination of the lower limit of detection of boron Ka and titanium La. In both cases, the lower limit of detection of 0.4 nm equivalent layer thickness was achieved (about 1.10 -7 g/cm 2 to 2.10 -7 g/cm 2 or 3.10 15 atoms/cm 2 to

  4. Further development of IDGS: Isotope dilution gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Li, T.K.; Parker, J.L.; Kuno, Y.; Sato, S.; Kamata, M.; Akiyama, T.

    1991-01-01

    The isotope dilution gamma-ray spectrometry (IDGS) technique for determining the plutonium concentration and isotopic composition of highly radioactive spent-fuel dissolver solutions has been further developed. Both the sample preparation and the analysis have been improved. The plutonium isotopic analysis is based on high-resolution, low-energy gamma-ray spectrometry. The plutonium concentration in the dissolver solutions then is calculated from the measured isotopic differences among the spike, the dissolver solution, and the spiked dissolver solution. Plutonium concentrations and isotopic compositions of dissolver solutions analyzed from this study agree well with those obtained by traditional isotope dilution mass spectrometry (IDMS) and are consistent with the first IDGS experimental result. With the current detector efficiency, sample size, and a 100-min count time, the estimated precision is ∼0.5% for 239 Pu and 240 Pu isotopic analyses and ∼1% for the plutonium concentration analysis. 5 refs., 2 figs., 7 tabs

  5. Determination of sulfur in food by high resolution continuum source flame molecular absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Zambrzycka, Elżbieta; Godlewska-Żyłkiewicz, Beata, E-mail: bgodlew@uwb.edu.pl

    2014-11-01

    In the present work, a fast, simple and sensitive analytical method for determination of sulfur in food and beverages by high resolution continuum source flame molecular absorption spectrometry was developed. The determination was performed via molecular absorption of carbon monosulfide, CS. Different CS rotational lines (257.959 nm, 258.033 nm, 258.055 nm), number of pixels and types of standard solution of sulfur, namely: sulfuric acid, sodium sulfate, ammonium sulfate, sodium sulfite, sodium sulfide, DL-cysteine, and L-cystine, were studied in terms of sensitivity, repeatability of results as well as limit of detection and limit of quantification. The best results were obtained for measurements of absorption of the CS molecule at 258.055 nm at the wavelength range covering 3 pixels and DL-cysteine in 0.2 mol L{sup −1} HNO{sub 3} solution as a calibration standard. Under optimized conditions the limit of detection and the limit of quantification achieved for sulfur were 10.9 mg L{sup −1} and 36.4 mg L{sup −1}, respectively. The repeatability of the results expressed as relative standard deviation was typically < 5%. The accuracy of the method was tested by analysis of digested biological certified reference materials (soya bean flour, corn flour and herbs) and recovery experiment for beverage samples with added known amount of sulfur standard. The recovery of analyte from such samples was in the range of 93–105% with the repeatability in the range of 4.1–5.0%. The developed method was applied for the determination of sulfur in milk (194 ± 10 mg kg{sup −1}), egg white (2188 ± 29 mg kg{sup −1}), mineral water (31.0 ± 0.9 mg L{sup −1}), white wine (260 ± 4 mg L{sup −1}) and red wine (82 ± 2 mg L{sup −1}), as well as in sample rich in ions, such as bitter mineral water (6900 ± 100 mg L{sup −1}). - Highlights: • HR-CS FMAS technique was used for sulfur measurement via molecular absorption of carbon monosulfide, CS. • Organic DL

  6. Investigation of chemical modifiers for phosphorus in a graphite furnace using high-resolution continuum source atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Lepri, Fabio G.; Dessuy, Morgana B.; Vale, Maria Goreti R.; Borges, Daniel L.G.; Welz, Bernhard; Heitmann, Uwe

    2006-01-01

    Phosphorus is not one of the elements that are typically determined by atomic absorption spectrometry, but this technique nevertheless offers several advantages that make it attractive, such as the relatively great freedom from interferences. As the main resonance lines for phosphorus are in the vacuum-ultraviolet, inaccessible by conventional atomic absorption spectrometry equipment, L'vov and Khartsyzov proposed to use the non-resonance doublet at 213.5 / 213.6 nm. Later it turned out that with conventional equipment it is necessary to use a chemical modifier in order to get reasonable sensitivity, and lanthanum was the first one suggested for that purpose. In the following years more than 30 modifiers have been proposed for the determination of this element, and there is no consensus about the best one. In this work high-resolution continuum source atomic absorption spectrometry has been used to investigate the determination of phosphorus without a modifier and with the addition of selected modifiers of very different nature, including the originally recommended lanthanum modifier, several palladium-based modifiers and sodium fluoride. As high-resolution continuum source atomic absorption spectrometry is revealing the spectral environment of the analytical line at high resolution, it became obvious that without the addition of a modifier essentially no atomic phosphorus is formed, even at 2700 deg. C . The absorption measured with line source atomic absorption spectrometry in this case is due to the PO molecule, the spectrum of which is overlapping with the atomic line. Palladium, with or without the addition of calcium or ascorbic acid, was found to be the only modifier to produce almost exclusively atomic phosphorus. Lanthanum and particularly sodium fluoride produced a mixture of P and PO, depending on the atomization temperature. This fact can explain at least some of the discrepancies found in the literature and some of the phenomena observed in the

  7. Handbook on Mobile Gamma-ray Spectrometry

    DEFF Research Database (Denmark)

    Aage, Helle Karina; Korsbech, Uffe C C

    2003-01-01

    Basic physics and mathematics for Airborne and Car-borne Gamma-ray Spectrometry supplemented with practical examples and methods for advanced data processing......Basic physics and mathematics for Airborne and Car-borne Gamma-ray Spectrometry supplemented with practical examples and methods for advanced data processing...

  8. Bayesian approach to peak deconvolution and library search for high resolution gas chromatography - Mass spectrometry

    NARCIS (Netherlands)

    Barcaru, A.; Mol, H.G.J.; Tienstra, M.; Vivó-Truyols, G.

    2017-01-01

    A novel probabilistic Bayesian strategy is proposed to resolve highly coeluting peaks in high-resolution GC-MS (Orbitrap) data. Opposed to a deterministic approach, we propose to solve the problem probabilistically, using a complete pipeline. First, the retention time(s) for a (probabilistic) number

  9. Decreasing of the detection limit for gamma-ray Spectrometry with the influence of sample treatment

    International Nuclear Information System (INIS)

    Karami, M.; Sadighzadeh, A.; Asgharizadeh, F.; Sardari, D.; Tavassoli, A.; Arbabi, A.; Hochaghani, O.

    2009-01-01

    Full text: In this study the ash method has been applied for environmental sample treatment in order to decrease of the detection limit in gamma-ray spectrometry for low level radioactivity measurements. Detection limit in gamma ray spectrometry is the smallest expectation value of the net counting rate that can be detected on given probabilities. The environmental test samples have been changed into ash using a suitable oven. The heating were made under controlled temperature to avoid the escape of some radionuclides such as radiocaesium. The ash samples were measured by high resolution gamma-ray spectrometry system. (author)

  10. Current use of high-resolution mass spectrometry in drug screening relevant to clinical and forensic toxicology and doping control.

    Science.gov (United States)

    Ojanperä, Ilkka; Kolmonen, Marjo; Pelander, Anna

    2012-05-01

    Clinical and forensic toxicology and doping control deal with hundreds or thousands of drugs that may cause poisoning or are abused, are illicit, or are prohibited in sports. Rapid and reliable screening for all these compounds of different chemical and pharmaceutical nature, preferably in a single analytical method, is a substantial effort for analytical toxicologists. Combined chromatography-mass spectrometry techniques with standardised reference libraries have been most commonly used for the purpose. In the last ten years, the focus has shifted from gas chromatography-mass spectrometry to liquid chromatography-mass spectrometry, because of progress in instrument technology and partly because of the polarity and low volatility of many new relevant substances. High-resolution mass spectrometry (HRMS), which enables accurate mass measurement at high resolving power, has recently evolved to the stage that is rapidly causing a shift from unit-resolution, quadrupole-dominated instrumentation. The main HRMS techniques today are time-of-flight mass spectrometry and Orbitrap Fourier-transform mass spectrometry. Both techniques enable a range of different drug-screening strategies that essentially rely on measuring a compound's or a fragment's mass with sufficiently high accuracy that its elemental composition can be determined directly. Accurate mass and isotopic pattern acts as a filter for confirming the identity of a compound or even identification of an unknown. High mass resolution is essential for improving confidence in accurate mass results in the analysis of complex biological samples. This review discusses recent applications of HRMS in analytical toxicology.

  11. A 3D CZT high resolution detector for x- and gamma-ray astronomy

    DEFF Research Database (Denmark)

    Kuvvetli, Irfan; Budtz-Jørgensen, Carl; Zappettini, A.

    2014-01-01

    At DTU Space we have developed a high resolution three dimensional (3D) position sensitive CZT detector for high energy astronomy. The design of the 3D CZT detector is based on the CZT Drift Strip detector principle. The position determination perpendicular to the anode strips is performed using...

  12. Profiling of modified nucleosides from ribonucleic acid digestion by supercritical fluid chromatography coupled to high resolution mass spectrometry.

    Science.gov (United States)

    Laboureur, Laurent; Guérineau, Vincent; Auxilien, Sylvie; Yoshizawa, Satoko; Touboul, David

    2018-02-16

    A method based on supercritical fluid chromatography coupled to high resolution mass spectrometry for the profiling of canonical and modified nucleosides was optimized, and compared to classical reverse-phase liquid chromatography in terms of separation, number of detected modified nucleosides and sensitivity. Limits of detection and quantification were measured using statistical method and quantifications of twelve nucleosides of a tRNA digest from E. coli are in good agreement with previously reported data. Results highlight the complementarity of both separation techniques to cover the largest view of nucleoside modifications for forthcoming epigenetic studies. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Bayesian approach to peak deconvolution and library search for high resolution gas chromatography - Mass spectrometry.

    Science.gov (United States)

    Barcaru, A; Mol, H G J; Tienstra, M; Vivó-Truyols, G

    2017-08-29

    A novel probabilistic Bayesian strategy is proposed to resolve highly coeluting peaks in high-resolution GC-MS (Orbitrap) data. Opposed to a deterministic approach, we propose to solve the problem probabilistically, using a complete pipeline. First, the retention time(s) for a (probabilistic) number of compounds for each mass channel are estimated. The statistical dependency between m/z channels was implied by including penalties in the model objective function. Second, Bayesian Information Criterion (BIC) is used as Occam's razor for the probabilistic assessment of the number of components. Third, a probabilistic set of resolved spectra, and their associated retention times are estimated. Finally, a probabilistic library search is proposed, computing the spectral match with a high resolution library. More specifically, a correlative measure was used that included the uncertainties in the least square fitting, as well as the probability for different proposals for the number of compounds in the mixture. The method was tested on simulated high resolution data, as well as on a set of pesticides injected in a GC-Orbitrap with high coelution. The proposed pipeline was able to detect accurately the retention times and the spectra of the peaks. For our case, with extremely high coelution situation, 5 out of the 7 existing compounds under the selected region of interest, were correctly assessed. Finally, the comparison with the classical methods of deconvolution (i.e., MCR and AMDIS) indicates a better performance of the proposed algorithm in terms of the number of correctly resolved compounds. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Gamma-line intensity difference method for sup 1 sup 1 sup 7 sup m Sn at high resolution

    CERN Document Server

    Remeikis, V; Mazeika, K

    1998-01-01

    The method for detection of small differences in the gamma-spectrum line intensity for the radionuclide in different environments has been developed for measurements at high resolution. The experiments were realized with the pure germanium planar detector. Solution of the methodical problems allowed to measure the relative difference DELTA IOTA subgamma/IOTA subgamma=(3.4+-1.5)*10 sup - sup 4 of the sup 1 sup 1 sup 7 sup m Sn 156.02 keV gamma-line intensity for the radionuclide in SnO sub 2 with respect to SnS from the difference in the gamma-spectra. The error of the result is caused mainly by the statistical accuracy. It is limited by the highest counting rate at sufficiently high energy resolution and relatively short half-life of sup 1 sup 1 sup 7 sup m Sn. (author)

  15. High-resolution Mass Spectrometry of Skin Mucus for Monitoring Physiological Impacts in Fish Exposed to Wastewater Effluent at a Great Lakes AOC

    Science.gov (United States)

    High-resolution mass spectrometry is advantageous for monitoring physiological impacts and contaminant biotransformation products in fish exposed to complex wastewater effluent. We evaluated this technique using skin mucus from male and female fathead minnows (Pimephales promela...

  16. A Rough Guide to Metabolite Identification Using High Resolution Liquid Chromatography Mass Spectrometry in Metabolomic Profiling in Metazoans

    Directory of Open Access Journals (Sweden)

    David G Watson

    2013-01-01

    Full Text Available Compound identification in mass spectrometry based metabolomics can be a problem but sometimes the problem seems to be presented in an over complicated way. The current review focuses on metazoans where the range of metabolites is more restricted than for example in plants. The focus is on liquid chromatography with high resolution mass spectrometry where it is proposed that most of the problems in compound identification relate to structural isomers rather than to isobaric compounds. Thus many of the problems faced relate to separation of isomers, which is usually required even if fragmentation is used to support structural identification. Many papers report the use of MS/MS or MS2 as an adjunct to the identification of known metabolites but there a few examples in metabolomics studies of metazoans of complete structure elucidation of novel metabolites or metabolites where no authentic standards are available for comparison.

  17. DETECTING LOW-LEVEL SYNTHESIS IMPURITIES IN MODIFIED PHOSPHOROTHIOATE OLIGONUCLEOTIDES USING LIQUID CHROMATOGRAPHY – HIGH RESOLUTION MASS SPECTROMETRY

    Science.gov (United States)

    Nikcevic, Irena; Wyrzykiewicz, Tadeusz K.; Limbach, Patrick A.

    2010-01-01

    Summary An LC-MS method based on the use of high resolution Fourier transform ion cyclotron resonance mass spectrometry (FTIRCMS) for profiling oligonucleotides synthesis impurities is described. Oligonucleotide phosphorothioatediesters (phosphorothioate oligonucleotides), in which one of the non-bridging oxygen atoms at each phosphorus center is replaced by a sulfur atom, are now one of the most popular oligonucleotide modifications due to their ease of chemical synthesis and advantageous pharmacokinetic properties. Despite significant progress in the solid-phase oligomerization chemistry used in the manufacturing of these oligonucleotides, multiple classes of low-level impurities always accompany synthetic oligonucleotides. Liquid chromatography-mass spectrometry has emerged as a powerful technique for the identification of these synthesis impurities. However, impurity profiling, where the entire complement of low-level synthetic impurities is identified in a single analysis, is more challenging. Here we present an LC-MS method based the use of high resolution-mass spectrometry, specifically Fourier transform ion cyclotron resonance mass spectrometry (FTIRCMS or FTMS). The optimal LC-FTMS conditions, including the stationary phase and mobile phases for the separation and identification of phosphorothioate oligonucleotides, were found. The characteristics of FTMS enable charge state determination from single m/z values of low-level impurities. Charge state information then enables more accurate modeling of the detected isotopic distribution for identification of the chemical composition of the detected impurity. Using this approach, a number of phosphorothioate impurities can be detected by LC-FTMS including failure sequences carrying 3′-terminal phosphate monoester and 3′-terminal phosphorothioate monoester, incomplete backbone sulfurization and desulfurization products, high molecular weight impurities, and chloral, isobutyryl, and N3 (2-cyanoethyl) adducts

  18. Feasibility of high-resolution continuum source molecular absorption spectrometry in flame and furnace for sulphur determination in petroleum products

    Science.gov (United States)

    Kowalewska, Zofia

    2011-07-01

    For the first time, high-resolution molecular absorption spectrometry with a high-intensity xenon lamp as radiation source has been applied for the determination of sulphur in crude oil and petroleum products. The samples were analysed as xylene solutions using vaporisation in acetylene-air flame or in an electrothermally heated graphite furnace. The sensitive rotational lines of the CS molecule, belonging to the ∆ν = 0 vibrational sequence within the electronic transition X 1∑ + → A 1П, were applied. For graphite furnace molecular absorption spectrometry, the Pd + Mg organic modifier was selected. Strong interactions with Pd atoms enable easier decomposition of sulphur-containing compounds, likely through the temporal formation of Pd xS y molecules. At the 258.056 nm line, with the wavelength range covering central pixel ± 5 pixels and with application of interactive background correction, the detection limit was 14 ng in graphite furnace molecular absorption spectrometry and 18 mg kg -1 in flame molecular absorption spectrometry. Meanwhile, application of 2-points background correction found a characteristic mass of 12 ng in graphite furnace molecular absorption spectrometry and a characteristic concentration of 104 mg kg -1 in flame molecular absorption spectrometry. The range of application of the proposed methods turned out to be significantly limited by the properties of the sulphur compounds of interest. In the case of volatile sulphur compounds, which can be present in light petroleum products, severe difficulties were encountered. On the contrary, heavy oils and residues from distillation as well as crude oil could be analysed using both flame and graphite furnace vaporisation. The good accuracy of the proposed methods for these samples was confirmed by their mutual consistency and the results from analysis of reference samples (certified reference materials and home reference materials with sulphur content determined by X-ray fluorescence

  19. Feasibility of high-resolution continuum source molecular absorption spectrometry in flame and furnace for sulphur determination in petroleum products

    Energy Technology Data Exchange (ETDEWEB)

    Kowalewska, Zofia, E-mail: zofia.kowalewska@obr.pl

    2011-07-15

    For the first time, high-resolution molecular absorption spectrometry with a high-intensity xenon lamp as radiation source has been applied for the determination of sulphur in crude oil and petroleum products. The samples were analysed as xylene solutions using vaporisation in acetylene-air flame or in an electrothermally heated graphite furnace. The sensitive rotational lines of the CS molecule, belonging to the {Delta}{nu} = 0 vibrational sequence within the electronic transition X{sup 1}{Sigma}{sup +} {yields} A{sup 1}{Pi}, were applied. For graphite furnace molecular absorption spectrometry, the Pd + Mg organic modifier was selected. Strong interactions with Pd atoms enable easier decomposition of sulphur-containing compounds, likely through the temporal formation of Pd{sub x}S{sub y} molecules. At the 258.056 nm line, with the wavelength range covering central pixel {+-} 5 pixels and with application of interactive background correction, the detection limit was 14 ng in graphite furnace molecular absorption spectrometry and 18 mg kg{sup -1} in flame molecular absorption spectrometry. Meanwhile, application of 2-points background correction found a characteristic mass of 12 ng in graphite furnace molecular absorption spectrometry and a characteristic concentration of 104 mg kg{sup -1} in flame molecular absorption spectrometry. The range of application of the proposed methods turned out to be significantly limited by the properties of the sulphur compounds of interest. In the case of volatile sulphur compounds, which can be present in light petroleum products, severe difficulties were encountered. On the contrary, heavy oils and residues from distillation as well as crude oil could be analysed using both flame and graphite furnace vaporisation. The good accuracy of the proposed methods for these samples was confirmed by their mutual consistency and the results from analysis of reference samples (certified reference materials and home reference materials with

  20. Fluorine determination in coal using high-resolution graphite furnace molecular absorption spectrometry and direct solid sample analysis

    Energy Technology Data Exchange (ETDEWEB)

    Machado, Patrícia M.; Morés, Silvane; Pereira, Éderson R. [Departamento de Química, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Welz, Bernhard, E-mail: w.bernardo@terra.com.br [Departamento de Química, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Instituto Nacional de Ciência e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, 40170-115 Salvador, BA (Brazil); Carasek, Eduardo [Departamento de Química, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Andrade, Jailson B. de [Instituto Nacional de Ciência e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, 40170-115 Salvador, BA (Brazil)

    2015-03-01

    The absorption of the calcium mono-fluoride (CaF) molecule has been employed in this study for the determination of fluorine in coal using direct solid sample analysis and high-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS GF MAS). The rotational line at 606.440 nm was used for measuring the molecular absorption in the gas phase. The pyrolysis and vaporization temperatures were 700 °C and 2100 °C, respectively. Different chemical modifiers have been studied, such as Pd and Ir as permanent modifiers, and Pd and the mixed Pd/Mg modifier in solution. The limit of detection and the characteristic mass were 0.3 and 0.1 ng F, respectively. One certified reference material (CRM) of coal (NIST 1635) and four CRMs with a non-certified value for F (SARM 18, SARM 20, BCR 40, BCR 180) were used to evaluate the accuracy and precision of the method, obtaining good agreement (104%) with the certified value and with the informed values (ranging from 90 to 103%). - Highlights: • High-resolution Graphite Furnace Molecular Absorption Spectrometry (HR-GF MAS) • Fluorine has been determined using HR-GF MAS of the CaF molecule. • The CaF molecule was generated in a graphite furnace at a temperature of 2100 °C • Coal samples have been analyzed using direct solid sample introduction. • Aqueous standard solutions have been used for calibration.

  1. Structural Characterisation of Acetogenins from Annona muricata by Supercritical Fluid Chromatography Coupled to High-Resolution Tandem Mass Spectrometry.

    Science.gov (United States)

    Laboureur, Laurent; Bonneau, Natacha; Champy, Pierre; Brunelle, Alain; Touboul, David

    2017-11-01

    Acetogenins are plant polyketides known to be cytotoxic and proposed as antitumor candidates. They are also suspected to be alimentary neurotoxins. Their occurrence as complex mixtures renders their dereplication and structural identification difficult using liquid chromatography coupled to tandem mass spectrometry and efforts are required to improve the methodology. To develop a supercritical fluid chromatography (SFC) high-resolution tandem mass spectrometry method, involving lithium post-column cationisation, for the structural characterisation of Annonaceous acetogenins in crude extracts. The seeds of Annona muricata L. were extracted with methanol. Supercritical fluid chromatography of the extract, using a 2-ethylpyridine stationary phase column, was monitored using a high-resolution quadrupole time-of-flight mass spectrometer. Lithium iodide was added post-column in the make-up solvent. For comparison, the same extract was analysed using high-pressure liquid chromatography coupled to the same mass spectrometer, with a column based on solid core particles. Sensitivity was similar for both HPLC and SFC approaches. Retention behaviour and fragmentation pathways of three different isomer groups are described. A previously unknown group of acetogenins was also evidenced for the first time. The use of SFC-MS/MS allows the reduction of the time of analysis, of environmental impact and an increase in the chromatographic resolution, compared to liquid chromatography. This new methodology enlightened a new group of acetogenins, isomers of montanacin-D. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  2. Determination of 239Pu/240Pu isotopic ratio by high resolution alpha-particle spectrometry

    International Nuclear Information System (INIS)

    Amoudry, F.; Burger, P.

    1983-05-01

    The development of passivated ion-implanted silicon detectors and of very thin alpha-particle sources improves the resolution of alpha-particle spectra and allows to separate energy pics up to now unseparate. The 239 Pu/ 240 Pu isotopic ratio of a mixture has been measured using the alpha spectrometry deconvolution code DEMO [fr

  3. Geant4 simulation of a 3D high resolution gamma camera

    International Nuclear Information System (INIS)

    Akhdar, H.; Kezzar, K.; Aksouh, F.; Assemi, N.; AlGhamdi, S.; AlGarawi, M.; Gerl, J.

    2015-01-01

    The aim of this work is to develop a 3D gamma camera with high position resolution and sensitivity relying on both distance/absorption and Compton scattering techniques and without using any passive collimation. The proposed gamma camera is simulated in order to predict its performance using the full benefit of Geant4 features that allow the construction of the needed geometry of the detectors, have full control of the incident gamma particles and study the response of the detector in order to test the suggested geometries. Three different geometries are simulated and each configuration is tested with three different scintillation materials (LaBr3, LYSO and CeBr3)

  4. High-resolution gamma spectroscopy with whole-body and partial-body counters. Experience, recommendations. Report

    International Nuclear Information System (INIS)

    Sahre, P.

    1997-12-01

    The application of high-resolution gamma spectroscopy with whole-body and partial-body counters shows a steadily rising upward trend over the last few years. This induced the ''Arbeitskreis Inkorporationsueberwachung'' of the association ''Fachverband fuer Strahlenschutz e.V.'' to organise a meeting for joint elaboration of a guide on recommended applications of this measuring technique, based on a review of existing experience and results. A key item on the agenda of the meeting was the comparative evaluation of the Ge semiconductor detector and the NaI solid scintillation detector. (orig./CB) [de

  5. Classification of wine by determination of bioactive phenolic compounds using high resolution mass spectrometry

    OpenAIRE

    Ivanova, Violeta; Dimovska, Violeta; Mitrev, Sasa; Gulaboski, Rubin; Bogeva, Elena; Petruseva, Dragana; Causon, Tim; Hann, Stephan

    2016-01-01

    In this project proposal, metabolomic fingerprinting of wine samples will be examined using high performance liquid chromatography combined with ion mobility quadruple time-of-flight mass spectrometry (HPLC–IMS-QTOF-MS) for the first time. Bioactive compounds in wines from various red and white varieties produced in Macedonia and Austria from different wine regions and different vintages will be determined for the first time using a non-targeted fingerprinting approach on this analytical plat...

  6. Targeting high-performance liquid chromatography-high-resolution mass spectrometry-solid-phase extraction-nuclear magnetic resonance analysis with high-resolution radical scavenging profiles - bioactive secondary metabolites from the endophytic fungus Penicillium namyslowskii

    DEFF Research Database (Denmark)

    Wubshet, Sileshi Gizachew; Nyberg, Nils; Tejesvi, Mysore V.

    2013-01-01

    The high-resolution radical scavenging profile of an extract of the endophytic fungus Penicillium namyslowskii was used to target analysis by high-performance liquid chromatography-high-resolution mass spectrometry-solid-phase extraction-nuclear magnetic resonance spectroscopy, i.e., HPLC...... NMR probe designed for 1.7-mm NMR tubes. To further explore the potential of the above HPLC-HRMS-SPE-NMR platform for analysis of endophytic extracts, six peaks displaying no radical scavenging activity were also analyzed. This allowed unambiguous identification of six metabolites, i...... and griseofulvin, directly from crude extract via HPLC-HRMS-SPE-NMR. Dechlorodehydrogriseofulvin was reported for the first time from nature....

  7. Identification of Vitamin D3 Oxidation Products Using High-Resolution and Tandem Mass Spectrometry

    Science.gov (United States)

    Mahmoodani, Fatemeh; Perera, Conrad O.; Abernethy, Grant; Fedrizzi, Bruno; Greenwood, David; Chen, Hong

    2018-03-01

    In a successful fortification program, the stability of micronutrients added to the food is one of the most important factors. The added vitamin D3 is known to sometimes decline during storage of fortified milks, and oxidation through fatty acid lipoxidation could be suspected as the likely cause. Identification of vitamin D3 oxidation products (VDOPs) in natural foods is a challenge due to the low amount of their contents and their possible transformation to other compounds during analysis. The main objective of this study was to find a method to extract VDOPs in simulated whole milk powder and to identify these products using LTQ-ion trap, Q-Exactive Orbitrap and triple quadrupole mass spectrometry. The multistage mass spectrometry (MSn) spectra can help to propose plausible schemes for unknown compounds and their fragmentations. With the growth of combinatorial libraries, mass spectrometry (MS) has become an important analytical technique because of its speed of analysis, sensitivity, and accuracy. This study was focused on identifying the fragmentation rules for some VDOPs by incorporating MS data with in silico calculated MS fragmentation pathways. Diels-Alder derivatization was used to enhance the sensitivity and selectivity for the VDOPs' identification. Finally, the confirmed PTAD-derivatized target compounds were separated and analyzed using ESI(+)-UHPLC-MS/MS in multiple reaction monitoring (MRM) mode. [Figure not available: see fulltext.

  8. Application of spatially resolved high resolution crystal spectrometry to inertial confinement fusion plasmas.

    Science.gov (United States)

    Hill, K W; Bitter, M; Delgado-Aparacio, L; Pablant, N A; Beiersdorfer, P; Schneider, M; Widmann, K; Sanchez del Rio, M; Zhang, L

    2012-10-01

    High resolution (λ∕Δλ ∼ 10 000) 1D imaging x-ray spectroscopy using a spherically bent crystal and a 2D hybrid pixel array detector is used world wide for Doppler measurements of ion-temperature and plasma flow-velocity profiles in magnetic confinement fusion plasmas. Meter sized plasmas are diagnosed with cm spatial resolution and 10 ms time resolution. This concept can also be used as a diagnostic of small sources, such as inertial confinement fusion plasmas and targets on x-ray light source beam lines, with spatial resolution of micrometers, as demonstrated by laboratory experiments using a 250-μm (55)Fe source, and by ray-tracing calculations. Throughput calculations agree with measurements, and predict detector counts in the range 10(-8)-10(-6) times source x-rays, depending on crystal reflectivity and spectrometer geometry. Results of the lab demonstrations, application of the technique to the National Ignition Facility (NIF), and predictions of performance on NIF will be presented.

  9. Screening new psychoactive substances in urban wastewater using high resolution mass spectrometry.

    Science.gov (United States)

    González-Mariño, Iria; Gracia-Lor, Emma; Bagnati, Renzo; Martins, Claudia P B; Zuccato, Ettore; Castiglioni, Sara

    2016-06-01

    Analysis of drug residues in urban wastewater could complement epidemiological studies in detecting the use of new psychoactive substances (NPS), a continuously changing group of drugs hard to monitor by classical methods. We initially selected 52 NPS potentially used in Italy based on seizure data and consumption alerts provided by the Antidrug Police Department and the National Early Warning System. Using a linear ion trap-Orbitrap high resolution mass spectrometer, we designed a suspect screening and a target method approach and compared them for the analysis of 24 h wastewater samples collected at the treatment plant influents of four Italian cities. This highlighted the main limitations of these two approaches, so we could propose requirements for future research. A library of MS/MS spectra of 16 synthetic cathinones and 19 synthetic cannabinoids, for which analytical standards were acquired, was built at different collision energies and is available on request. The stability of synthetic cannabinoids was studied in analytical standards and wastewater, identifying the best analytical conditions for future studies. To the best of our knowledge, these are the first stability data on NPS. Few suspects were identified in Italian wastewater samples, in accordance with recent epidemiological data reporting a very low prevalence of use of NPS in Italy. This study outlines an analytical approach for NPS identification and measurement in urban wastewater and for estimating their use in the population.

  10. Isotopomer analysis of lipid biosynthesis by high resolution mass spectrometry and NMR

    Energy Technology Data Exchange (ETDEWEB)

    Lane, Andrew N., E-mail: anlane01@louisville.edu [JG Brown Cancer Center, 529 S. Jackson Street, Louisville, KY 40202 (United States); Center for Regulatory and Environmental Analytical Metabolomics (CREAM), University of Louisville, Louisville, KY (United States); Fan, Teresa W.-M. [JG Brown Cancer Center, 529 S. Jackson Street, Louisville, KY 40202 (United States); Center for Regulatory and Environmental Analytical Metabolomics (CREAM), University of Louisville, Louisville, KY (United States); Department of Chemistry, University of Louisville, Louisville, KY 40292 (United States); Xie, Zhengzhi; Moseley, Hunter N.B.; Higashi, Richard M. [Center for Regulatory and Environmental Analytical Metabolomics (CREAM), University of Louisville, Louisville, KY (United States); Department of Chemistry, University of Louisville, Louisville, KY 40292 (United States)

    2009-10-05

    We have coupled 2D-NMR and infusion FT-ICR-MS with computer-assisted assignment to profile {sup 13}C-isotopologues of glycerophospholipids (GPL) directly in crude cell extracts, resulting in very high information throughput of >3000 isobaric molecules in a few minutes. A mass accuracy of better than 1 ppm combined with a resolution of 100,000 at the measured m/z was required to distinguish isotopomers from other GPL structures. Isotopologue analysis of GPLs extracted from LCC2 breast cancer cells grown on [U-{sup 13}C]-glucose provided a rich trove of information about the biosynthesis and turnover of the GPLs. The isotopologue intensity ratios from the FT-ICR-MS were accurate to {approx}1% or better based on natural abundance background, and depended on the signal-to-nose ratio. The time course of incorporation of {sup 13}C from [U-{sup 13}C]-glucose into a particular phosphatidylcholine was analyzed in detail, to provide a quantitative measure of the sizes of glycerol, acetyl CoA and total GPL pools in growing LCC2 cells. Independent and complementary analysis of the positional {sup 13}C enrichment in the glycerol and fatty acyl chains obtained from high resolution 2D NMR was used to verify key aspects of the model. This technology enables simple and rapid sample preparation, has rapid analysis, and is generally applicable to unfractionated GPLs of almost any head group, and to mixtures of other classes of metabolites.

  11. Isotopomer analysis of lipid biosynthesis by high resolution mass spectrometry and NMR

    International Nuclear Information System (INIS)

    Lane, Andrew N.; Fan, Teresa W.-M.; Xie, Zhengzhi; Moseley, Hunter N.B.; Higashi, Richard M.

    2009-01-01

    We have coupled 2D-NMR and infusion FT-ICR-MS with computer-assisted assignment to profile 13 C-isotopologues of glycerophospholipids (GPL) directly in crude cell extracts, resulting in very high information throughput of >3000 isobaric molecules in a few minutes. A mass accuracy of better than 1 ppm combined with a resolution of 100,000 at the measured m/z was required to distinguish isotopomers from other GPL structures. Isotopologue analysis of GPLs extracted from LCC2 breast cancer cells grown on [U- 13 C]-glucose provided a rich trove of information about the biosynthesis and turnover of the GPLs. The isotopologue intensity ratios from the FT-ICR-MS were accurate to ∼1% or better based on natural abundance background, and depended on the signal-to-nose ratio. The time course of incorporation of 13 C from [U- 13 C]-glucose into a particular phosphatidylcholine was analyzed in detail, to provide a quantitative measure of the sizes of glycerol, acetyl CoA and total GPL pools in growing LCC2 cells. Independent and complementary analysis of the positional 13 C enrichment in the glycerol and fatty acyl chains obtained from high resolution 2D NMR was used to verify key aspects of the model. This technology enables simple and rapid sample preparation, has rapid analysis, and is generally applicable to unfractionated GPLs of almost any head group, and to mixtures of other classes of metabolites.

  12. Formation properties from high resolution neutron activation gamma-ray spectra

    International Nuclear Information System (INIS)

    Mellor, D.W.; Underwood, M.C.

    1985-01-01

    A neutron activation logging tool has been developed comprising a Five Curie /sup 241/ Am-Be neutron source and a large n-type hyper-pure germanium gamma-ray detector. The tool maintains a constant temperature cryogenic environment for periods in excess of twenty hours. No liquid nitrogen or other consumable material is used in the operating or recharging stages. A large calibration tank in simulated well-bore geometry has been constructed with sand bodies saturated with oil and low salinity water (14,000 ppm NaCl). In the water zone prompt neutron capture gamma-rays from silicon, hydrogen and chlorine were prominent; gamma-rays from inelastic scattering on oxygen and silicon were detected. No gamma-rays arising from inelastic scattering on carbon were detected. These data have been interpreted to yield the porosity, fluid saturations, salinity and matrix composition. In the oil zone, gamma-rays arising from inelastic scattering on oxygen, silicon and carbon were detected. The intensity of the carbon line was very poor, and inadequate for quantitative purposes

  13. A Modular Pipelined Processor for High Resolution Gamma-Ray Spectroscopy

    Science.gov (United States)

    Veiga, Alejandro; Grunfeld, Christian

    2016-02-01

    The design of a digital signal processor for gamma-ray applications is presented in which a single ADC input can simultaneously provide temporal and energy characterization of gamma radiation for a wide range of applications. Applying pipelining techniques, the processor is able to manage and synchronize very large volumes of streamed real-time data. Its modular user interface provides a flexible environment for experimental design. The processor can fit in a medium-sized FPGA device operating at ADC sampling frequency, providing an efficient solution for multi-channel applications. Two experiments are presented in order to characterize its temporal and energy resolution.

  14. Identification of amines in wintertime ambient particulate material using high resolution aerosol mass spectrometry

    Science.gov (United States)

    Bottenus, Courtney L. H.; Massoli, Paola; Sueper, Donna; Canagaratna, Manjula R.; VanderSchelden, Graham; Jobson, B. Thomas; VanReken, Timothy M.

    2018-05-01

    Significant amounts of amines were detected in fine particulate matter (PM) during ambient wintertime conditions in Yakima, WA, using a high resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS). Positive matrix factorization (PMF) of the organic aerosol (OA) signal resulted in a six-factor solution that included two previously unreported amine OA factors. The contributions of the amine factors were strongly episodic, but the concentration of the combined amine factors was as high as 10-15 μg m-3 (2-min average) during those episodes. In one occasion, the Amine-II component was 45% of total OA signal. The Amine-I factor was dominated by spectral peaks at m/z 86 (C5H12N+) and m/z 100 (C6H14N+), while the Amine-II factor was dominated by spectral peaks at m/z 58 (C3H8N+ and C2H6N2+) and m/z 72 (C4H10N+ and C3H8N2+). The ions dominating each amine factor showed distinct time traces, suggesting different sources or formation processes. Investigation into the chemistry of the amine factors suggests a correlation with inorganic anions for Amine-I, but no evidence that the Amine-II was being neutralized by the same inorganic ions. We also excluded the presence of organonitrates (ON) in the OA. The presence of C2H4O2+ at m/z 60 (a levoglucosan fragment) in the Amine-I spectrum suggests some influence of biomass burning emissions (more specifically residential wood combustion) in this PMF factor, but wind direction suggested that the most likely sources of these amines were agricultural activities and feedlots to the S-SW of the site.

  15. High-resolution mass spectrometry driven discovery of peptidic danger signals in insect immunity.

    Directory of Open Access Journals (Sweden)

    Arton Berisha

    Full Text Available The 'danger model' is an alternative concept for immune response postulating that the immune system reacts to entities that do damage (danger associated molecular patterns, DAMP and not only to entities that are foreign (pathogen-associated molecular patterns, PAMP as proposed by classical immunology concepts. In this study we used Galleria mellonella to validate the danger model in insects. Hemolymph of G. mellonella was digested with thermolysin (as a representative for virulence-associated metalloproteinases produced by humanpathogens followed by chromatographic fractionation. Immune-stimulatory activity was tested by measuring lysozyme activity with the lytic zone assays against Micrococcus luteus cell wall components. Peptides were analyzed by nano-scale liquid chromatography coupled to high-resolution Fourier transform mass spectrometers. Addressing the lack of a genome sequence we complemented the rudimentary NCBI protein database with a recently established transcriptome and de novo sequencing methods for peptide identification. This approach led to identification of 127 peptides, 9 of which were identified in bioactive fractions. Detailed MS/MS experiments in comparison with synthetic analogues confirmed the amino acid sequence of all 9 peptides. To test the potential of these putative danger signals to induce immune responses we injected the synthetic analogues into G. mellonella and monitored the anti-bacterial activity against living Micrococcus luteus. Six out of 9 peptides identified in the bioactive fractions exhibited immune-stimulatory activity when injected. Hence, we provide evidence that small peptides resulting from thermolysin-mediated digestion of hemolymph proteins function as endogenous danger signals which can set the immune system into alarm. Consequently, our study indicates that the danger model also plays a role in insect immunity.

  16. Advanced techniques for high resolution spectroscopic observations of cosmic gamma-ray sources

    International Nuclear Information System (INIS)

    Matteson, J.L.; Pelling, M.R.; Peterson, L.E.

    1985-08-01

    We describe an advanced gamma-ray spectrometer that is currently in development. It will obtain a sensitivity of -4 ph/cm -2 -sec in a 6 hour balloon observation and uses innovative techniques for background reduction and source imaging

  17. Urinary detection of conjugated and unconjugated anabolic steroids by dilute-and-shoot liquid chromatography-high resolution mass spectrometry.

    Science.gov (United States)

    Tudela, Eva; Deventer, Koen; Geldof, Lore; Van Eenoo, Peter

    2015-02-01

    Anabolic androgenic steroids (AAS) are an important class of doping agents. The metabolism of these substances is generally very extensive and includes phase-I and phase-II pathways. In this work, a comprehensive detection of these metabolites is described using a 2-fold dilution of urine and subsequent analysis by liquid chromatography-high resolution mass spectrometry (LC-HRMS). The method was applied to study 32 different metabolites, excreted free or conjugated (glucuronide or sulfate), which permit the detection of misuse of at least 21 anabolic steroids. The method has been fully validated for 21 target compounds (8 glucuronide, 1 sulfate and 12 free steroids) and 18 out of 21 compounds had detection limits in the range of 1-10 ng mL(-1) in urine. For the conjugated compounds, for which no reference standards are available, metabolites were synthesized in vitro or excretion studies were investigated. The detection limits for these compounds ranged between 0.5 and 18 ng mL(-1) in urine. The simple and straightforward methodology complements the traditional methods based on hydrolysis, liquid-liquid extraction, derivatization and analysis by gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS). Copyright © 2014 John Wiley & Sons, Ltd.

  18. Structural Characterization of a Thrombin-Aptamer Complex by High Resolution Native Top-Down Mass Spectrometry

    Science.gov (United States)

    Zhang, Jiang; Loo, Rachel R. Ogorzalek; Loo, Joseph A.

    2017-09-01

    Native mass spectrometry (MS) with electrospray ionization (ESI) has evolved as an invaluable tool for the characterization of intact native proteins and non-covalently bound protein complexes. Here we report the structural characterization by high resolution native top-down MS of human thrombin and its complex with the Bock thrombin binding aptamer (TBA), a 15-nucleotide DNA with high specificity and affinity for thrombin. Accurate mass measurements revealed that the predominant form of native human α-thrombin contains a glycosylation mass of 2205 Da, corresponding to a sialylated symmetric biantennary oligosaccharide structure without fucosylation. Native MS showed that thrombin and TBA predominantly form a 1:1 complex under near physiological conditions (pH 6.8, 200 mM NH4OAc), but the binding stoichiometry is influenced by the solution ionic strength. In 20 mM ammonium acetate solution, up to two TBAs were bound to thrombin, whereas increasing the solution ionic strength destabilized the thrombin-TBA complex and 1 M NH4OAc nearly completely dissociated the complex. This observation is consistent with the mediation of thrombin-aptamer binding through electrostatic interactions and it is further consistent with the human thrombin structure that contains two anion binding sites on the surface. Electron capture dissociation (ECD) top-down MS of the thrombin-TBA complex performed with a high resolution 15 Tesla Fourier transform ion cyclotron resonance (FTICR) mass spectrometer showed the primary binding site to be at exosite I located near the N-terminal sequence of the heavy chain, consistent with crystallographic data. High resolution native top-down MS is complementary to traditional structural biology methods for structurally characterizing native proteins and protein-DNA complexes. [Figure not available: see fulltext.

  19. Site-specific glycosylation of donkey milk lactoferrin investigated by high-resolution mass spectrometry

    DEFF Research Database (Denmark)

    Gallina, Serafina; Saletti, Rosaria; Cunsolo, Vincenzo

    2016-01-01

    A comprehensive monosaccharide composition of the N-glycans of donkey milk lactoferrin, isolated by ion exchange chromatography from an individual milk sample, was obtained by means of chymotryptic digestion, TiO2 and HILIC enrichment, reversed-phase high-performance liquid chromatography......, electrospray mass spectrometry, and high collision dissociation fragmentation. The results obtained allowed identifying 26 different glycan structures, including high mannose, complex and hybrid N-glycans, linked to the protein backbone via an amide bond to asparagine residues located at the positions 137, 281...... and 476. Altogether, the N-glycan structures determined revealed that most of the N-glycans identified in donkey milk lactoferrin are neutral complex/hybrid. Indeed, 10 neutral non-fucosylated complex/hybrid N-glycans and 4 neutral fucosylated complex/hybrid N-glycans were found. In addition, two high...

  20. Cryogenic microcalorimeter system for ultra-high resolution alpha-particle spectrometry

    International Nuclear Information System (INIS)

    Rabin, Michael W.; Hoover, Andrew S.; Bacrania, Minesh K.; Croce, Mark P.; Hoteling, N.J.; Lamont, S.P.; Plionis, A.A.; Dry, D.E.; Ullom, J.N.; Bennett, D.A.; Horansky, R.; Kotsubo, V.; Cantor, R.

    2009-01-01

    Microcalorimeters have been shown to yield unsurpassed energy resolution for alpha spectrometry, up to 1.06 keV FWHM at 5.3 MeV. These detectors use a superconducting transition-edge sensor (TES) to measure the temperature change in an absorber from energy deposited by an interacting alpha particle. Our system has four independent detectors mounted inside a liquid nitrogen/liquid helium cryostat. An adiabatic demagnetization refrigerator (ADR) cools the detector stage to its operating temperature of 80 mK. Temperature regulation with ∼15 uK peak-to-peak variation is achieved by PID control of the ADR. The detectors are voltage-biased, and the current signal is amplified by a commercial SQUID readout system and digitized for further analysis, This paper will discuss design and operation of our microcalorimeter alpha spectrometer, and will show recent results.

  1. Cryogenic Microcalorimeter System for Ultra-High Resolution Alpha-Particle Spectrometry

    Science.gov (United States)

    Croce, M. P.; Bacrania, M. K.; Hoover, A. S.; Rabin, M. W.; Hoteling, N. J.; LaMont, S. P.; Plionis, A. A.; Dry, D. E.; Ullom, J. N.; Bennett, D. A.; Horansky, R. D.; Kotsubo, V.; Cantor, R.

    2009-12-01

    Microcalorimeters have been shown to yield unsurpassed energy resolution for alpha spectrometry, up to 1.06 keV FWHM at 5.3 MeV. These detectors use a superconducting transition-edge sensor (TES) to measure the temperature change in an absorber from energy deposited by an interacting alpha particle. Our system has four independent detectors mounted inside a liquid nitrogen/liquid helium cryostat. An adiabatic demagnetization refrigerator (ADR) cools the detector stage to its operating temperature of 80 mK. Temperature regulation with ˜15-μK peak-to-peak variation is achieved by PID control of the ADR. The detectors are voltage-biased, and the current signal is amplified by a commercial SQUID readout system and digitized for further analysis. This paper will discuss design and operation of our microcalorimeter alpha-particle spectrometer, and will show recent results.

  2. Phase I and phase II reductive metabolism simulation of nitro aromatic xenobiotics with electrochemistry coupled with high resolution mass spectrometry.

    Science.gov (United States)

    Bussy, Ugo; Chung-Davidson, Yu-Wen; Li, Ke; Li, Weiming

    2014-11-01

    Electrochemistry combined with (liquid chromatography) high resolution mass spectrometry was used to simulate the general reductive metabolism of three biologically important nitro aromatic molecules: 3-trifluoromethyl-4-nitrophenol (TFM), niclosamide, and nilutamide. TFM is a pesticide used in the Laurential Great Lakes while niclosamide and nilutamide are used in cancer therapy. At first, a flow-through electrochemical cell was directly connected to a high resolution mass spectrometer to evaluate the ability of electrochemistry to produce the main reduction metabolites of nitro aromatic, nitroso, hydroxylamine, and amine functional groups. Electrochemical experiments were then carried out at a constant potential of -2.5 V before analysis of the reduction products by LC-HRMS, which confirmed the presence of the nitroso, hydroxylamine, and amine species as well as dimers. Dimer identification illustrates the reactivity of the nitroso species with amine and hydroxylamine species. To investigate xenobiotic metabolism, the reactivity of nitroso species to biomolecules was also examined. Binding of the nitroso metabolite to glutathione was demonstrated by the observation of adducts by LC-ESI(+)-HRMS and the characteristics of their MSMS fragmentation. In conclusion, electrochemistry produces the main reductive metabolites of nitro aromatics and supports the observation of nitroso reactivity through dimer or glutathione adduct formation.

  3. Expanding the linear dynamic range for quantitative liquid chromatography-high resolution mass spectrometry utilizing natural isotopologue signals

    International Nuclear Information System (INIS)

    Liu, Hanghui; Lam, Lily; Yan, Lin; Chi, Bert; Dasgupta, Purnendu K.

    2014-01-01

    Highlights: • Less abundant isotopologue ions were utilized to decrease detector saturation. • A 25–50 fold increase in the upper limit of dynamic range was demonstrated. • Linear dynamic range was expanded without compromising mass resolution. - Abstract: The linear dynamic range (LDR) for quantitative liquid chromatography–mass spectrometry can be extended until ionization saturation is reached by using a number of target isotopologue ions in addition to the normally used target ion that provides the highest sensitivity. Less abundant isotopologue ions extend the LDR: the lower ion abundance decreases the probability of ion detector saturation. Effectively the sensitivity decreases and the upper limit of the LDR increases. We show in this paper that the technique is particularly powerful with a high resolution time of flight mass spectrometer because the data for all ions are automatically acquired, and we demonstrated this for four small organic molecules; the upper limits of LDRs increased by 25–50 times

  4. Urban gamma spectrometry. Report 1

    International Nuclear Information System (INIS)

    Aage, H.K.; Kuukankorpi, S.; Moring, M.; Smolander, P.; Toivonen, H.

    2009-06-01

    This report contains the present status and results for the NKS UGS-project per 1 June 2006 for NKS partners DTU, Denmark, and STUK, Finland. The Danish and Finnish CGS (Carborne Gamma Spectrometry) systems are not of similar types. The Danish CGS system(s) only make use of one NaI(Tl) detector whereas the Finnish CGS system consists of several detectors, NaI(Tl) and HPGe both and as an additional feature the Finnish detectors have position dependent different fields of view. Furthermore, the Finnish system is equipped with an air sampling system. In terms of operation, the Danish detector is located on the rooftop where as the Finnish detectors are located inside the vehicle. The Finnish and the Danish team use different methods for data processing. STUK uses a hypothesis test method to get robust real time alarms (within 10 seconds) when significant peaks from a previously defined set of nuclides are detected. An alarm for a significantly elevated total pulse rate is sent if none of the predefined nuclides is identified. All data are stored to the LINSSI database, which facilitates easy data retrieval for post processing. DEMA/DTU bases their calculations on full spectrum fitting using NASVD and the Danish software NucSpec. Source signals are found from spectrum fitting residuals or from stripping of energy windows - either by the standard 4-windows method or by a measurement based method where stripping factors for any window of interest can be derived from the measurements themselves. A thorough description of the two systems and data processing methods (including mathematics) are described in this report. For the Danish methods of data processing some comparisons have been made, but no final conclusion has been reached yet. Raw urban data has been investigated along with urban data sets to which source signals have been added and searched for. For the Finnish method calibration plots of the minimum detection limits for two different detector types have been

  5. Urban gamma spectrometry. Report 1

    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

    This report contains the present status and results for the NKS UGS-project per 1 June 2006 for NKS partners DTU, Denmark, and STUK, Finland. The Danish and Finnish CGS (Carborne Gamma Spectrometry) systems are not of similar types. The Danish CGS system(s) only make use of one NaI(Tl) detector whereas the Finnish CGS system consists of several detectors, NaI(Tl) and HPGe both and as an additional feature the Finnish detectors have position dependent different fields of view. Furthermore, the Finnish system is equipped with an air sampling system. In terms of operation, the Danish detector is located on the rooftop where as the Finnish detectors are located inside the vehicle. The Finnish and the Danish team use different methods for data processing. STUK uses a hypothesis test method to get robust real time alarms (within 10 seconds) when significant peaks from a previously defined set of nuclides are detected. An alarm for a significantly elevated total pulse rate is sent if none of the predefined nuclides is identified. All data are stored to the LINSSI database, which facilitates easy data retrieval for post processing. DEMA/DTU bases their calculations on full spectrum fitting using NASVD and the Danish software NucSpec. Source signals are found from spectrum fitting residuals or from stripping of energy windows - either by the standard 4-windows method or by a measurement based method where stripping factors for any window of interest can be derived from the measurements themselves. A thorough description of the two systems and data processing methods (including mathematics) are described in this report. For the Danish methods of data processing some comparisons have been made, but no final conclusion has been reached yet. Raw urban data has been investigated along with urban data sets to which source signals have been added and searched for. For the Finnish method calibration plots of the minimum detection limits for two different detector types have been

  6. High-resolution studies of momentum distributions using perfect crystal gamma diffractometry

    International Nuclear Information System (INIS)

    Krexner, G.; Bischof, G.; Jentschel, M.; Boerner, H.

    2006-01-01

    Full text: Positron annihilation spectroscopy has turned out to be highly successful in the investigation of Fermi surfaces, electronic structures and various kinds of defects. On the other hand, algorithms based on density functional theory have made enormous progress in recent years and calculations for the contributions of both delocalized and core electrons in a rapidly increasing number of systems is either already feasible today or to be expected in the near future. By comparison, over the last decades there has been little improvement in the experimental limitations which are still set by the energy resolution of germanium detectors (slightly above 1 keV for annihilation photons close to 500 keV) and the angular resolution in ACAR studies (superior by about one order of magnitude). In addition, coincidence techniques are hampered by low count rates. An alternative is suggested by the fact that, in principle, Bragg diffraction techniques using perfect single crystals provide a way for the precise determination of wavelengths corresponding to energies in the MeV range. The single crystal analyzer instrument PN3 at the Institute Laue-Langevin (Grenoble, France) offers the unique possibility to determine the energy of annihilation photons with an accuracy close to about 1 eV, i.e. an improvement of up to three orders of magnitude in comparison to conventional semiconductor detectors. We discuss possible applications of this spectrometer in high-resolution studies of momentum distributions for both delocalized and core electrons. (author)

  7. Triacylglycerol profiling of microalgae strains for biofuel feedstock by liquid chromatography-high-resolution mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    MacDougall, Karen M.; McNichol, Jesse; McGinn, Patrick J.; O' Leary, Stephen J.B.; Melanson, Jeremy E. [Institute for Marine Biosciences, National Research Council of Canada, Halifax, NS (Canada)

    2011-11-15

    Biofuels from photosynthetic microalgae are quickly gaining interest as a viable carbon-neutral energy source. Typically, characterization of algal feedstock involves breaking down triacylglycerols (TAG) and other intact lipids, followed by derivatization of the fatty acids to fatty acid methyl esters prior to analysis by gas chromatography (GC). However, knowledge of the intact lipid profile could offer significant advantages for discovery stage biofuel research such as the selection of an algal strain or the optimization of growth and extraction conditions. Herein, lipid extracts from microalgae were directly analyzed by ultra-high pressure liquid chromatography-mass spectrometry (UHPLC-MS) using a benchtop Orbitrap mass spectrometer. Phospholipids, glycolipids, and TAGs were analyzed in the same chromatographic run, using a combination of accurate mass and diagnostic fragment ions for identification. Using this approach, greater than 100 unique TAGs were identified over the six algal strains studied and TAG profiles were obtained to assess their potential for biofuel applications. Under the growth conditions employed, Botryococcus braunii and Scenedesmus obliquus yielded the most comprehensive TAG profile with a high abundance of TAGs containing oleic acid. (orig.)

  8. A 3D high-resolution gamma camera for radiopharmaceutical studies with small animals

    CERN Document Server

    Loudos, G K; Giokaris, N D; Styliaris, E; Archimandritis, S C; Varvarigou, A D; Papanicolas, C N; Majewski, S; Weisenberger, D; Pani, R; Scopinaro, F; Uzunoglu, N K; Maintas, D; Stefanis, K

    2003-01-01

    The results of studies conducted with a small field of view tomographic gamma camera based on a Position Sensitive Photomultiplier Tube are reported. The system has been used for the evaluation of radiopharmaceuticals in small animals. Phantom studies have shown a spatial resolution of 2 mm in planar and 2-3 mm in tomographic imaging. Imaging studies in mice have been carried out both in 2D and 3D. Conventional radiopharmaceuticals have been used and the results have been compared with images from a clinically used system.

  9. A high resolution gamma-ray spectrometer based on superconducting microcalorimeters

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, D. A.; Horansky, R. D. [National Institute of Standards and Technology, Boulder, Colorado 80305 (United States); University of Denver, Denver, Colorado 80208 (United States); Schmidt, D. R.; Doriese, W. B.; Fowler, J. W.; Kotsubo, V.; Mates, J. A. B. [National Institute of Standards and Technology, Boulder, Colorado 80305 (United States); University of Colorado, Boulder, Colorado 80309 (United States); Hoover, A. S.; Winkler, R.; Rabin, M. W. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Alpert, B. K.; Beall, J. A.; Fitzgerald, C. P.; Hilton, G. C.; Irwin, K. D.; O' Neil, G. C.; Reintsema, C. D.; Schima, F. J.; Swetz, D. S.; Vale, L. R. [National Institute of Standards and Technology, Boulder, Colorado 80305 (United States); and others

    2012-09-15

    Improvements in superconductor device fabrication, detector hybridization techniques, and superconducting quantum interference device readout have made square-centimeter-sized arrays of gamma-ray microcalorimeters, based on transition-edge sensors (TESs), possible. At these collecting areas, gamma microcalorimeters can utilize their unprecedented energy resolution to perform spectroscopy in a number of applications that are limited by closely-spaced spectral peaks, for example, the nondestructive analysis of nuclear materials. We have built a 256 pixel spectrometer with an average full-width-at-half-maximum energy resolution of 53 eV at 97 keV, a useable dynamic range above 400 keV, and a collecting area of 5 cm{sup 2}. We have demonstrated multiplexed readout of the full 256 pixel array with 236 of the pixels (91%) giving spectroscopic data. This is the largest multiplexed array of TES microcalorimeters to date. This paper will review the spectrometer, highlighting the instrument design, detector fabrication, readout, operation of the instrument, and data processing. Further, we describe the characterization and performance of the newest 256 pixel array.

  10. High resolution phoswich gamma-ray imager utilizing monolithic MPPC arrays with submillimeter pixelized crystals

    Science.gov (United States)

    Kato, T.; Kataoka, J.; Nakamori, T.; Kishimoto, A.; Yamamoto, S.; Sato, K.; Ishikawa, Y.; Yamamura, K.; Kawabata, N.; Ikeda, H.; Kamada, K.

    2013-05-01

    We report the development of a high spatial resolution tweezers-type coincidence gamma-ray camera for medical imaging. This application consists of large-area monolithic Multi-Pixel Photon Counters (MPPCs) and submillimeter pixelized scintillator matrices. The MPPC array has 4 × 4 channels with a three-side buttable, very compact package. For typical operational gain of 7.5 × 105 at + 20 °C, gain fluctuation over the entire MPPC device is only ± 5.6%, and dark count rates (as measured at the 1 p.e. level) amount to acrylic light guide measuring 1 mm thick, and with summing operational amplifiers that compile the signals into four position-encoded analog outputs being used for signal readout. Spatial resolution of 1.1 mm was achieved with the coincidence imaging system using a 22Na point source. These results suggest that the gamma-ray imagers offer excellent potential for applications in high spatial medical imaging.

  11. High-resolution imaging gamma-ray spectroscopy with externally segmented germanium detectors

    Science.gov (United States)

    Callas, J. L.; Mahoney, W. A.; Varnell, L. S.; Wheaton, W. A.

    1993-01-01

    Externally segmented germanium detectors promise a breakthrough in gamma-ray imaging capabilities while retaining the superb energy resolution of germanium spectrometers. An angular resolution of 0.2 deg becomes practical by combining position-sensitive germanium detectors having a segment thickness of a few millimeters with a one-dimensional coded aperture located about a meter from the detectors. Correspondingly higher angular resolutions are possible with larger separations between the detectors and the coded aperture. Two-dimensional images can be obtained by rotating the instrument. Although the basic concept is similar to optical or X-ray coded-aperture imaging techniques, several complicating effects arise because of the penetrating nature of gamma rays. The complications include partial transmission through the coded aperture elements, Compton scattering in the germanium detectors, and high background count rates. Extensive electron-photon Monte Carlo modeling of a realistic detector/coded-aperture/collimator system has been performed. Results show that these complicating effects can be characterized and accounted for with no significant loss in instrument sensitivity.

  12. First characterization of AKB-48 metabolism, a novel synthetic cannabinoid, using human hepatocytes and high-resolution mass spectrometry.

    Science.gov (United States)

    Gandhi, Adarsh S; Zhu, Mingshe; Pang, Shaokun; Wohlfarth, Ariane; Scheidweiler, Karl B; Liu, Hua-Fen; Huestis, Marilyn A

    2013-10-01

    Since the federal authorities scheduled the first synthetic cannabinoids, JWH-018 and JWH-073, new synthetic cannabinoids were robustly marketed. N-(1-Adamantyl)-1-pentylindazole-3-carboxamide (AKB-48), also known as APINACA, was recently observed in Japanese herbal smoking blends. The National Forensic Laboratory Information System registered 443 reports of AKB-48 cases in the USA from March 2010 to January 2013. In May 2013, the Drug Enforcement Administration listed AKB-48 as a Schedule I drug. Recently, AKB-48 was shown to have twice the CB1 receptor binding affinity than CB2. These pharmacological effects and the difficulty in detecting the parent compound in urine highlight the importance of metabolite identification for developing analytical methods for clinical and forensic investigations. Using human hepatocytes and TripleTOF mass spectrometry, we identified 17 novel phase I and II AKB-48 metabolites, products of monohydroxylation, dihydroxylation, or trihydroxylation on the aliphatic adamantane ring or N-pentyl side chain. Glucuronide conjugation of some mono- and dihydroxylated metabolites also occurred. Oxidation and dihydroxylation on the adamantane ring and N-pentyl side chain formed a ketone. More metabolites were identified after 3 h of incubation than at 1 h. For the first time, we present a AKB-48 metabolic scheme obtained from human hepatocytes and high-resolution mass spectrometry. These data are needed to develop analytical methods to identify AKB-48 consumption in clinical and forensic testing.

  13. Evaluation and optimization of high-performance liquid chromatography coupled with high-resolution mass spectrometry for phospholipid quantitation.

    Science.gov (United States)

    Fu, Mingkun; Xu, Wei; Lu, Qing; Pan, Guoyu; Varga, Csanad

    2014-04-15

    High-performance liquid chromatography coupled with high-resolution mass spectrometry (HPLC/HRMS) provides an attractive alternative to the traditional triple quadrupole mass spectrometry selected reaction monitoring (SRM) methodology in the field of quantitation. An LTQ Orbitrap Velos mass spectrometer coupled with a Shimadzu UHPLC system was used. A mass extraction window (MEW) was defined to mathematically correlate with mass resolving power (MRP). Five MRP measurement conditions at 7500, 15,000, 30,000, 60,000, and 100,000, and five MEW widths at 10%, 20%, 50%, and 100% of ±1000000/MRP, and were utilized as the experimental conditions. Comparison of profile and centroid algorithms was evaluated as well. Selection of pH 8.5 buffer, C4 column, 20% IPA, and 10 ppm H3 PO4 , minimized hydrophobic and silanol interactions to enhance separation. Narrowing the MEW minimized background noise, while over-narrowing the MEW gave signal loss due to mass accuracy deviation. The mass accuracy deviation was larger for lower MRP measurements especially with centriod data, and hence a profile algorithm was recommended. The post-ionization signal suppression was observed with low MRP and was further confirmed with the analysis of multi-level linearity. It was found that the HPLC/HRMS method with conditions of 20% ±1000000/MRP as MEW, 30,000 or 60,000 MRP, and profile algorithm, provide optimum results for quantitation of seven model phospholipids. Copyright © 2014 John Wiley & Sons, Ltd.

  14. Discovery of putative salivary biomarkers for Sjögren's syndrome using high resolution mass spectrometry and bioinformatics.

    Science.gov (United States)

    Zoukhri, Driss; Rawe, Ian; Singh, Mabi; Brown, Ashley; Kublin, Claire L; Dawson, Kevin; Haddon, William F; White, Earl L; Hanley, Kathleen M; Tusé, Daniel; Malyj, Wasyl; Papas, Athena

    2012-03-01

    The purpose of the current study was to determine if saliva contains biomarkers that can be used as diagnostic tools for Sjögren's syndrome (SjS). Twenty seven SjS patients and 27 age-matched healthy controls were recruited for these studies. Unstimulated glandular saliva was collected from the Wharton's duct using a suction device. Two µl of salvia were processed for mass spectrometry analyses on a prOTOF 2000 matrix-assisted laser desorption/ionization orthogonal time of flight (MALDI O-TOF) mass spectrometer. Raw data were analyzed using bioinformatic tools to identify biomarkers. MALDI O-TOF MS analyses of saliva samples were highly reproducible and the mass spectra generated were very rich in peptides and peptide fragments in the 750-7,500 Da range. Data analysis using bioinformatic tools resulted in several classification models being built and several biomarkers identified. One model based on 7 putative biomarkers yielded a sensitivity of 97.5%, specificity of 97.8% and an accuracy of 97.6%. One biomarker was present only in SjS samples and was identified as a proteolytic peptide originating from human basic salivary proline-rich protein 3 precursor. We conclude that salivary biomarkers detected by high-resolution mass spectrometry coupled with powerful bioinformatic tools offer the potential to serve as diagnostic/prognostic tools for SjS.

  15. Determination of boron isotope ratios by high-resolution continuum source molecular absorption spectrometry using graphite furnace vaporizers

    Science.gov (United States)

    Abad, Carlos; Florek, Stefan; Becker-Ross, Helmut; Huang, Mao-Dong; Heinrich, Hans-Joachim; Recknagel, Sebastian; Vogl, Jochen; Jakubowski, Norbert; Panne, Ulrich

    2017-10-01

    Boron isotope amount ratios n(10B)/n(11B) have been determined by monitoring the absorption spectrum of boron monohydride (BH) in a graphite furnace using high-resolution continuum source molecular absorption spectrometry (HR-CS-MAS). Bands (0 → 0) and (1 → 1) for the electronic transition X1Σ+ → A1Π were evaluated around wavelengths 433.1 nm and 437.1 nm respectively. Clean and free of memory effect molecular spectra of BH were recorded. In order to eliminate the memory effect of boron, a combination of 2% (v/v) hydrogen gas in argon and 1% trifluoromethane in argon, an acid solution of calcium chloride and mannitol as chemical modifiers was used. Partial least square regression (PLS) for analysis of samples and reference materials were applied. For this, a spectral library with different isotopes ratios for PLS regression was built. Results obtained around the 433.1 nm and 437.1 nm spectral regions are metrologically compatible with those reported by mass spectrometric methods. Moreover, for the evaluated region of 437 nm, an accuracy of 0.15‰ is obtained as the average deviation from the isotope reference materials. Expanded uncertainties with a coverage factor of k = 2 range between 0.15 and 0.44‰. This accuracy and precision are compatible with those obtained by mass spectrometry for boron isotope ratio measurements.

  16. The determination of polycyclic aromatic hydrocarbons in human urine by high-resolution gas chromatography-mass spectrometry.

    Science.gov (United States)

    Cho, Sung-Hee; Lee, Sun-Kyung; Kim, Chong Hyeak

    2018-05-01

    Polycyclic aromatic hydrocarbons (PAHs), organic compounds formed by at least two condensed aromatic rings, are ubiquitous environmental pollutants that are produced by incomplete combustion of organic materials. PAHs have been classified as carcinogenIC to humans by the International Agency for Research on Cancer, because they can bind to DNA, causing mutations. Therefore, the levels of PAHs in human urine can be used as an indicator for potential carcinogenesis and cell mutation. An analytical method was developed for the accurate measurement of PAHs in urine using high-resolution gas chromatography-mass spectrometry. Urine samples were extracted by an Oasis HLB extraction cartridge after enzymatic hydrolysis with a β-glucuronidase/arylsulfatase cocktail. The 18 PAHs were separated using an Agilent DB-5 MS capillary column (30 m × 0.25 mm, 0.25 μm) and monitored by time-of-flight mass spectrometry. Under the optimized method, the linearity of calibration curves was >0.994. The limits of detection at a signal-to-noise ratio of 3 were 10-100 ng/L. The coefficients of variation were in the range of 0.4-9.0%. The present method was highly accurate for simultaneous determination of 18 PAHs in human urine and could be applied to monitoring and biomedical investigations to check exposure of PAHs. Copyright © 2017 John Wiley & Sons, Ltd.

  17. Molecular characterization of phytoplankton dissolved organic matter (DOM) and sulfur components using high resolution Orbitrap mass spectrometry.

    Science.gov (United States)

    Mangal, Vaughn; Stock, Naomi L; Guéguen, Celine

    2016-03-01

    Orbitrap high resolution mass spectrometry (HRMS) with electrospray ionization in both positive and negative polarity was conducted on Suwannee River fulvic acid (SRFA), Pony Lake fulvic acid (PLFA) standards, and dissolved organic matter (DOM) released by freshwater phytoplankton (Scenedesmus obliquus, Euglena mutabilis, and Euglena gracilis). Three-dimensional van Krevelen diagrams expressing various oxygenation states of sulfur molecules and abundance plots of sulfur-containing species were constructed. Orbitrap HRMS analysis of SRFA found a high density of peaks in the lignin region (77 %) and low density of protein material (6.53 %), whereas for PLFA, 25 % of the total peaks were lignin related compared to 56 % of peaks in protein regions, comparable with other HRMS studies. Phytoplankton-derived DOM of S. obliquus, E. mutabilis, and E. gracilis was dominated by protein molecules at respective percentages of 36, 46, and 49 %, and is consistent with previous experiments examining phytoplankton-derived DOM composition. The normalized percentage of SO-containing compounds was determined among the three phytoplankton to be 56 % for Scenedesmus, 54 % for E. mutabilis, and 47 % for E. gracilis, suggesting variation between sulfur content in phytoplankton-derived DOM and differences in metal binding capacities. These results suggest the level of resolution by Orbitrap mass spectrometry is sufficient for preliminary characterization of phytoplankton DOM at an affordable cost relative to other HRMS techniques.

  18. Data on endogenous bovine ovarian follicular cells peptides and small proteins obtained through Top-down High Resolution Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Valérie Labas

    2017-08-01

    Full Text Available The endogenous peptides and small proteins extracted from bovine ovarian follicular cells (oocytes, cumulus and granulosa cells were identified by Top-down High Resolution Mass Spectrometry (TD-HR-MS/MS in order to annotate peptido- and proteoforms detected using qualitative and quantitative profiling method based on ICM-MS (Intact Cell Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry. The description and analysis of these Top-down MS data in the context of oocyte quality biomarkers research are available in the original research article of Labas et al. (2017 http://dx.doi.org/10.1016/j.jprot.2017.03.027 [1]. Raw data derived from this peptidomic/proteomic analysis have been deposited to the ProteomeXchange Consortium via the PRIDE partner repository (dataset identifier PXD004892. Here, we described the inventory of all identified peptido- and proteoforms including their biochemical and structural features, and functional annotation of correspondent proteins. This peptide/protein inventory revealed that TD-HR-MS/MS was appropriate method for both global and targeted proteomic analysis of ovarian tissues, and it can be further employed as a reference for other studies on follicular cells including single oocytes.

  19. SAMPO 90 high resolution interactive gamma-spectrum analysis including automation with macros

    International Nuclear Information System (INIS)

    Aarnio, P.A.; Nikkinen, M.T.; Routti, J.T.

    1992-01-01

    SAMPO 90 is high performance gamma-spectrum analysis program for personal computers. It uses color graphics to display calibrations, spectra, fitting results as multiplet components, and analysis results. All the analysis phases can be done either under full interactive user control or macros and programmable function keys can be used for completely automated measurement and analysis sequences including the control of MACs and sample changers. Accurate peak area determination of even the most complex multiplets, of up to 32 components, is accomplished using linear and mixed mode fitting. Nuclide identification is done using associated lines techniques allowing interference correction for fully overlapping peaks. Peaked Background Subtraction can be performed and Minimum Detectable Activities calculated. The analysis reports and program parameters are fully customizable. (author) 13 refs.; 1 fig

  20. Large microcalorimeter arrays for high-resolution X- and gamma-rayspectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Hoover, A.S., E-mail: ahoover@lanl.gov [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Hoteling, N.; Rabin, M.W. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Ullom, J.N.; Bennett, D.A. [National Institute of Standards and Technology, Boulder, CO 80305 (United States); Karpius, P.J.; Vo, D.T. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Doriese, W.B.; Hilton, G.C.; Horansky, R.D.; Irwin, K.D.; Kotsubo, V. [National Institute of Standards and Technology, Boulder, CO 80305 (United States); Lee, D.W. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Vale, L.R. [National Institute of Standards and Technology, Boulder, CO 80305 (United States)

    2011-10-01

    Microcalorimeter detectors provide unprecedented energy resolution for the measurement of X-rays and soft gamma-rays. Energy resolution in the 100 keV region can be up to an order of magnitude better than planar high-purity germanium (HPGe) detectors. The technology is well-suited to analysis of materials with complex spectra presenting closely spaced photopeaks. One application area is the measurement and assay of nuclear materials for safeguards and fuel cycle applications. In this paper, we discuss the operation and performance of a 256-pixel array, and present results of a head-to-head comparison of isotopic determination measurements with high-purity germanium using a plutonium standard. We show that the uncertainty of a single measurement is smaller for the microcalorimeter data compared to the HPGe data when photopeak areas are equal. We identify several key areas where analysis codes can be optimized that will likely lead to improvement in the microcalorimeter performance.

  1. Imaging of gamma rays with the WINKLER high-resolution germanium spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, T.R.; Hamilton, T.W.; Hawley, J.D.; Kilner, J.R.; Murphy, M.J.; Nakano, G.H. (Luckheed Palo Alto Research Lab., Palo Alto, CA (US))

    1990-06-01

    The WINKLER spectrometer is a matrix of nine high-purity {ital n}-type germanium detectors developed for astrophysical observations and terrestrial radiation monitoring. The spectrometer has been fitted with a set of modulation collimator grids designed for imaging hard x-ray and gamma-ray sources by the Mertz, Nakano, and Kilner method. This technique employs a pair of gridded collimators in front of each detector with the number of grid bars varying from one to {ital N}, where {ital N} is the number of detectors. When the collimator pairs are rotated through a full 360-degree angular range, the detector signals provide the information for a two-dimensional band-limited Fourier reconstruction of order {ital N}. Tests of the spectrometer with single and multiple point sources as well as continuous source distributions are reported.

  2. High resolution phoswich gamma-ray imager utilizing monolithic MPPC arrays with submillimeter pixelized crystals

    International Nuclear Information System (INIS)

    Kato, T; Kataoka, J; Nakamori, T; Kishimoto, A; Yamamoto, S; Sato, K; Ishikawa, Y; Yamamura, K; Kawabata, N; Ikeda, H; Kamada, K

    2013-01-01

    We report the development of a high spatial resolution tweezers-type coincidence gamma-ray camera for medical imaging. This application consists of large-area monolithic Multi-Pixel Photon Counters (MPPCs) and submillimeter pixelized scintillator matrices. The MPPC array has 4 × 4 channels with a three-side buttable, very compact package. For typical operational gain of 7.5 × 10 5 at + 20 °C, gain fluctuation over the entire MPPC device is only ± 5.6%, and dark count rates (as measured at the 1 p.e. level) amount to ≤ 400 kcps per channel. We selected Ce-doped (Lu,Y) 2 (SiO 4 )O (Ce:LYSO) and a brand-new scintillator, Ce-doped Gd 3 Al 2 Ga 3 O 12 (Ce:GAGG) due to their high light yield and density. To improve the spatial resolution, these scintillators were fabricated into 15 × 15 matrices of 0.5 × 0.5 mm 2 pixels. The Ce:LYSO and Ce:GAGG scintillator matrices were assembled into phosphor sandwich (phoswich) detectors, and then coupled to the MPPC array along with an acrylic light guide measuring 1 mm thick, and with summing operational amplifiers that compile the signals into four position-encoded analog outputs being used for signal readout. Spatial resolution of 1.1 mm was achieved with the coincidence imaging system using a 22 Na point source. These results suggest that the gamma-ray imagers offer excellent potential for applications in high spatial medical imaging.

  3. An automatic sample changer for gamma spectrometry

    International Nuclear Information System (INIS)

    Andrews, D.J.

    1984-01-01

    An automatic sample changer for gamma spectrometry is described which is designed for large-volume, low radioactivity environmental samples of various sizes up to maximum dimensions 100 mm diameter x 60 mm high. The sample changer is suitable for use with most existing gamma spectrometry systems which utilize GeLi or NaI detectors in vertical mode, in conjunction with a pulse height analyzer having auto-cycle and suitable data output facilities; it is linked to a Nuclear Data ND 6620 computer-based analysis system. (U.K.)

  4. High resolution gamma-ray spectroscopy at high count rates with a prototype High Purity Germanium detector

    Science.gov (United States)

    Cooper, R. J.; Amman, M.; Vetter, K.

    2018-04-01

    High-resolution gamma-ray spectrometers are required for applications in nuclear safeguards, emergency response, and fundamental nuclear physics. To overcome one of the shortcomings of conventional High Purity Germanium (HPGe) detectors, we have developed a prototype device capable of achieving high event throughput and high energy resolution at very high count rates. This device, the design of which we have previously reported on, features a planar HPGe crystal with a reduced-capacitance strip electrode geometry. This design is intended to provide good energy resolution at the short shaping or digital filter times that are required for high rate operation and which are enabled by the fast charge collection afforded by the planar geometry crystal. In this work, we report on the initial performance of the system at count rates up to and including two million counts per second.

  5. High-resolution gamma-ray spectroscopy with a microwave-multiplexed transition-edge sensor array

    Energy Technology Data Exchange (ETDEWEB)

    Noroozian, Omid [National Institute of Standards and Technology, Boulder, Colorado 80305 (United States); Center for Astrophysics and Space Astronomy, University of Colorado, Boulder, Colorado 80309 (United States); Mates, John A. B.; Bennett, Douglas A.; Brevik, Justus A.; Fowler, Joseph W.; Gao, Jiansong; Hilton, Gene C.; Horansky, Robert D.; Irwin, Kent D.; Schmidt, Daniel R.; Vale, Leila R.; Ullom, Joel N. [National Institute of Standards and Technology, Boulder, Colorado 80305 (United States); Kang, Zhao [Department of Physics, University of Colorado, Boulder, Colorado 80309 (United States)

    2013-11-11

    We demonstrate very high resolution photon spectroscopy with a microwave-multiplexed two-pixel transition-edge sensor (TES) array. We measured a {sup 153}Gd photon source and achieved an energy resolution of 63 eV full-width-at-half-maximum at 97 keV and an equivalent readout system noise of 86 pA/√(Hz) at the TES. The readout circuit consists of superconducting microwave resonators coupled to radio-frequency superconducting-quantum-interference-devices and transduces changes in input current to changes in phase of a microwave signal. We use flux-ramp modulation to linearize the response and evade low-frequency noise. This demonstration establishes one path for the readout of cryogenic X-ray and gamma-ray sensor arrays with more than 10{sup 3} elements and spectral resolving powers R=λ/Δλ>10{sup 3}.

  6. Desorption atmospheric pressure photoionization high-resolution mass spectrometry: a complementary approach for the chemical analysis of atmospheric aerosols.

    Science.gov (United States)

    Parshintsev, Jevgeni; Vaikkinen, Anu; Lipponen, Katriina; Vrkoslav, Vladimir; Cvačka, Josef; Kostiainen, Risto; Kotiaho, Tapio; Hartonen, Kari; Riekkola, Marja-Liisa; Kauppila, Tiina J

    2015-07-15

    On-line chemical characterization methods of atmospheric aerosols are essential to increase our understanding of physicochemical processes in the atmosphere, and to study biosphere-atmosphere interactions. Several techniques, including aerosol mass spectrometry, are nowadays available, but they all suffer from some disadvantages. In this research, desorption atmospheric pressure photoionization high-resolution (Orbitrap) mass spectrometry (DAPPI-HRMS) is introduced as a complementary technique for the fast analysis of aerosol chemical composition without the need for sample preparation. Atmospheric aerosols from city air were collected on a filter, desorbed in a DAPPI source with a hot stream of toluene and nitrogen, and ionized using a vacuum ultraviolet lamp at atmospheric pressure. To study the applicability of the technique for ambient aerosol analysis, several samples were collected onto filters and analyzed, with the focus being on selected organic acids. To compare the DAPPI-HRMS data with results obtained by an established method, each filter sample was divided into two equal parts, and the second half of the filter was extracted and analyzed by liquid chromatography/mass spectrometry (LC/MS). The DAPPI results agreed with the measured aerosol particle number. In addition to the targeted acids, the LC/MS and DAPPI-HRMS methods were found to detect different compounds, thus providing complementary information about the aerosol samples. DAPPI-HRMS showed several important oxidation products of terpenes, and numerous compounds were tentatively identified. Thanks to the soft ionization, high mass resolution, fast analysis, simplicity and on-line applicability, the proposed methodology has high potential in the field of atmospheric research. Copyright © 2015 John Wiley & Sons, Ltd.

  7. A specially designed cut-off gamma camera for high resolution SPECT of the brain

    International Nuclear Information System (INIS)

    Larsson, S.A.; Bergstrand, G.; Bergstedt, H.; Berg, J.; Flygare, O.; Schnell, P.O.; Anderson, N.; Lagergren, C.

    1984-01-01

    A modern gamma camera system for Single Photon Emission Computed Tomography (SPECT) has been modified in order to optimize examinations of the head. By cutting off a part of the detector housing at one edge, it has been possible to rotate the camera close to the skull, still covering the entire brain and the skull base. The minimum radius of rotation used was thereby reduced, in the mean, from 21.2 cm to 13.0 cm in examination of 18 patients. In combination with an adjustment of the 64 x 64 acquisition matrix to a field of view of 26x26 cm/sup 2/, the spatial resolution improved from 18.6 mm (FWHM) to 12.6 +- 0.3 mm (FWHM) using the conventional LEGP-collimator and to 10.4 +- 0.3 mm (FWHM) using the LEHR-collimator. No other modification than a slight cut of the light guide was made in the internal construction of the camera. Thus, the physical properties of the detector head are not essentially changed from those of a non-modified unit. The improved spatial resolution of the cut-off camera SPECT-system implies certain clinical advantages in studies of the brain, the cerebrospinal fluid (CSF)-space and the skull base

  8. High-resolution measurement of the {sup 16}O({gamma},pn) reaction

    Energy Technology Data Exchange (ETDEWEB)

    Isaksson, L.

    1996-10-01

    The {sup 16}O({gamma},pn) reaction has been measured with a resolution high enough to resolve individual low-lying states in the residual {sup 14}N nucleus. Partial cross-sections, available to the acceptance of the detector system, have been extracted for the individual states, and compared to a recent calculation based on absorption on one-pion exchange currents and the {Delta} resonance current. The experiment was performed at the Maxlab accelerator laboratory in Lund, Sweden, using tagged photons at an energy of 67 - 76 MeV. The proton detector angular range was 60 - 100 deg and the corresponding for the neutron detector 81 - 103 deg. A missing energy resolution of 1.5 MeV was obtained. The relative population of the states in the residual {sup 14}N nucleus indicates that the reaction takes place predominantly on proton-neutron pairs coupled to (J{sup {pi}},T) = (1{sup +},0). The cross-section for absorption on (0{sup +},1) pairs is strongly suppressed. Furthermore, the relative population of the states indicates that both L=0 and L=2 pairs participate in the reaction. 45 refs.

  9. Peak fitting and identification software library for high resolution gamma-ray spectra

    International Nuclear Information System (INIS)

    Uher, Josef; Roach, Greg; Tickner, James

    2010-01-01

    A new gamma-ray spectral analysis software package is under development in our laboratory. It can be operated as a stand-alone program or called as a software library from Java, C, C++ and MATLAB TM environments. It provides an advanced graphical user interface for data acquisition, spectral analysis and radioisotope identification. The code uses a peak-fitting function that includes peak asymmetry, Compton continuum and flexible background terms. Peak fitting function parameters can be calibrated as functions of energy. Each parameter can be constrained to improve fitting of overlapping peaks. All of these features can be adjusted by the user. To assist with peak identification, the code can automatically measure half-lives of single or multiple overlapping peaks from a time series of spectra. It implements library-based peak identification, with options for restricting the search based on radioisotope half-lives and reaction types. The software also improves the reliability of isotope identification by utilizing Monte-Carlo simulation results.

  10. Determination of uranium and thorium using gamma spectrometry: A pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Olivares, D.M.M.; Koch, E.S.; Manso Guevara, M.V.; Garcia Velasco, F., E-mail: diango.mo87@gmail.com [Universidade Estadual de Santa Cruz (UNESC), Ilhéus, BA (Brazil)

    2017-07-01

    This paper presents the results of a pilot experiment aimed at standardizing procedures for the CPqCTR/UESC Gamma Spectrometry Laboratory (LEG) for the quantification of natural radioactive elements in solid environmental samples. The concentrations of {sup 238}U, {sup 232}Th and {sup 40}K in two sediment matrix belonging to the Caetité region were determined, by using the absolute method with uncertainties about 5%. The results were obtained using gamma spectrometry with a high-resolution p-type HPGe detector. As a closure, the absorbed dose, radium equivalent activity and the annual effective dose were calculated. (author)

  11. Determination of uranium and thorium using gamma spectrometry: a pilot study

    Science.gov (United States)

    Olivares, D. M. M.; Koch, E. S.; Guevara, M. V. M.; Velasco, F. G.

    2018-03-01

    This paper presents the results of a pilot experiment aimed at standardizing procedures for the CPqCTR/UESC Gamma Spectrometry Laboratory (LEG) for the quantification of natural radioactive elements in solid environmental samples. The concentrations of 238U, 232Th and 40K in two sediment matrix belonging to the Caetité region were determined, by using the absolute method with uncertainties about 5%. The results were obtained using gamma spectrometry with a high-resolution p-type HPGe detector. As a closure, the absorbed dose, radium equivalent activity and the annual effective dose were calculated.

  12. 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)

  13. Airborne gamma-ray spectrometry

    DEFF Research Database (Denmark)

    Hovgaard, Jens

    A new method - Noise Adjusted Singular Value Decomposition, NASVD - for processing gamma-ray spectra has been developed as part of a Ph.D. project. By using this technique one is able to decompose a large set of data - for example from airborne gamma-ray surveys - into a few spectral components....... By knowing the spectral components and their amplitudes in each of the measured spectra one is able to extract more information from the data than possible with the methods used otherwise....

  14. High-Resolution Liquid Chromatography Tandem Mass Spectrometry Enables Large Scale Molecular Characterization of Dissolved Organic Matter

    Directory of Open Access Journals (Sweden)

    Daniel Petras

    2017-12-01

    Full Text Available Dissolved organic matter (DOM is arguably one of the most complex exometabolomes on earth, and is comprised of thousands of compounds, that together contribute more than 600 × 1015 g carbon. This reservoir is primarily the product of interactions between the upper ocean's microbial food web, yet abiotic processes that occur over millennia have also modified many of its molecules. The compounds within this reservoir play important roles in determining the rate and extent of element exchange between inorganic reservoirs and the marine biosphere, while also mediating microbe-microbe interactions. As such, there has been a widespread effort to characterize DOM using high-resolution analytical methods including nuclear magnetic resonance spectroscopy (NMR and mass spectrometry (MS. To date, molecular information in DOM has been primarily obtained through calculated molecular formulas from exact mass. This approach has the advantage of being non-targeted, accessing the inherent complexity of DOM. Molecular structures are however still elusive and the most commonly used instruments are costly. More recently, tandem mass spectrometry has been employed to more precisely identify DOM components through comparison to library mass spectra. Here we describe a data acquisition and analysis workflow that expands the repertoire of high-resolution analytical approaches available to access the complexity of DOM molecules that are amenable to electrospray ionization (ESI MS. We couple liquid chromatographic separation with tandem MS (LC-MS/MS and a data analysis pipeline, that integrates peak extraction from extracted ion chromatograms (XIC, molecular formula calculation and molecular networking. This provides more precise structural characterization. Although only around 1% of detectable DOM compounds can be annotated through publicly available spectral libraries, community-wide participation in populating and annotating DOM datasets could rapidly increase the

  15. Gamma strength functions and level densities from high-resolution inelastic proton scattering at very forward angles

    Science.gov (United States)

    Bassauer, Sergej; Neumann-Cosel, Peter von; Tamii, Atsushi

    2017-09-01

    Inelastic proton scattering at energies of a few 100 MeV and forward angles including 0∘ provides a novel method to measure gamma strength functions (GSF) in nuclei in an energy range of about 5-23 MeV. The experiments provide not only the E1 but also the M1 part of the GSF. The latter is poorly known in heavy nuclei. A case study of 208Pb indicates that the systematics proposed for the M1-GSF in RIPL-3 needs to be substantially revised. Comparison with gamma decay data (e.g. from the Oslo method) allows to test the generalised Brink-Axel (BA) hypothesis in the energy region of the pygmy dipole resonance (PDR) crucial for the modelling of (n,γ) and (γ,n) reactions in astrophysical reaction networks. A fluctuation analysis of the high-resolution data also provides a direct measure of level densities in the energy region well above the neutron threshold, where hardly any experimental information is available.

  16. Gamma strength functions and level densities from high-resolution inelastic proton scattering at very forward angles

    Directory of Open Access Journals (Sweden)

    Bassauer Sergej

    2017-01-01

    Full Text Available Inelastic proton scattering at energies of a few 100 MeV and forward angles including 0∘ provides a novel method to measure gamma strength functions (GSF in nuclei in an energy range of about 5–23 MeV. The experiments provide not only the E1 but also the M1 part of the GSF. The latter is poorly known in heavy nuclei. A case study of 208Pb indicates that the systematics proposed for the M1-GSF in RIPL-3 needs to be substantially revised. Comparison with gamma decay data (e.g. from the Oslo method allows to test the generalised Brink-Axel (BA hypothesis in the energy region of the pygmy dipole resonance (PDR crucial for the modelling of (n,γ and (γ,n reactions in astrophysical reaction networks. A fluctuation analysis of the high-resolution data also provides a direct measure of level densities in the energy region well above the neutron threshold, where hardly any experimental information is available.

  17. [Uncertainty evaluation of the determination of toxic equivalent quantity of polychlorinated dibenzo-p-dioxins and dibenzofurans in soil by isotope dilution high resolution gas chromatography and high resolution mass spectrometry].

    Science.gov (United States)

    Du, Bing; Liu Aimin; Huang, Yeru

    2014-09-01

    Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in soil samples were analyzed by isotope dilution method with high resolution gas chromatography and high resolution mass spectrometry (ID-HRGC/HRMS), and the toxic equivalent quantity (TEQ) were calculated. The impacts of major source of measurement uncertainty are discussed, and the combined relative standard uncertainties were calculated for each 2, 3, 7, 8 substituted con- gener. Furthermore, the concentration, combined uncertainty and expanded uncertainty for TEQ of PCDD/Fs in a soil sample in I-TEF, WHO-1998-TEF and WHO-2005-TEF schemes are provided as an example. I-TEF, WHO-1998-TEF and WHO-2005-TEF are the evaluation schemes of toxic equivalent factor (TEF), and are all currently used to describe 2,3,7,8 sub- stituted relative potencies.

  18. Enrichment Meter Dataset from High-Resolution Gamma Spectroscopy Measurements of U3O8 Enrichment Standards and UF6 Cylinder Wall Equivalents

    Energy Technology Data Exchange (ETDEWEB)

    Nicholson, Andrew D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Croft, Stephen [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Shephard, Adam M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-12-01

    The Enrichment Meter Principle (EMP) is the basis for a commonly used standard test method for the non-destructive assay of 235U enrichment in bulk compounds [1]. The technique involves determining the net count rate in the direct 186 keV peak using medium or high energy gamma-ray spectrometry in a fixed geometry. With suitable correction for wall attenuation, compound type, rate loss (live time), and peaked background (if significant), the atom fraction of 235U may be obtained from the counting rate from a linear relationship through the origin. The widespread use of this method for field verification of enrichment [2,3] together with the fact that the response function rests on fundamental physics considerations (i.e., is not represented by a convenient but arbitrary form) makes it an interesting example of uncertainty quantification, one in which one can expect a valid measurement model can be applied. When applied using NaI(Tl) and region of interest analysis, the technique is susceptible to both interference error and bias [2-4]. When implemented using high-resolution gamma-ray spectroscopy, the spectrum interpretation is considerable simplified and more robust [5]. However, a practical challenge to studying the uncertainty budget of the EMP method (for example, to test linearity, extract wall corrections and so forth using modern methods) is the availability of quality experimental data that can be referenced and shared. To fill this gap, the research team undertook an experimental campaign [6]. A measurement campaign was conducted to produce high-resolution gamma spectroscopy enrichment meter data comparable to UF6 cylinder measurements. The purpose of this report is to provide both an introduction to and quality assurance (QA) of the raw data produced. This report is intended for the analyst or researcher who uses the raw data. Unfortunately, the raw data (i.e., the spectra files) are too voluminous to include in this report

  19. Quantitative and Selective Analysis of Feline Growth Related Proteins Using Parallel Reaction Monitoring High Resolution Mass Spectrometry.

    Directory of Open Access Journals (Sweden)

    Mårten Sundberg

    Full Text Available Today immunoassays are widely used in veterinary medicine, but lack of species specific assays often necessitates the use of assays developed for human applications. Mass spectrometry (MS is an attractive alternative due to high specificity and versatility, allowing for species-independent analysis. Targeted MS-based quantification methods are valuable complements to large scale shotgun analysis. A method referred to as parallel reaction monitoring (PRM, implemented on Orbitrap MS, has lately been presented as an excellent alternative to more traditional selected reaction monitoring/multiple reaction monitoring (SRM/MRM methods. The insulin-like growth factor (IGF-system is not well described in the cat but there are indications of important differences between cats and humans. In feline medicine IGF-I is mainly analyzed for diagnosis of growth hormone disorders but also for research, while the other proteins in the IGF-system are not routinely analyzed within clinical practice. Here, a PRM method for quantification of IGF-I, IGF-II, IGF binding protein (BP -3 and IGFBP-5 in feline serum is presented. Selective quantification was supported by the use of a newly launched internal standard named QPrEST™. Homology searches demonstrated the possibility to use this standard of human origin for quantification of the targeted feline proteins. Excellent quantitative sensitivity at the attomol/μL (pM level and selectivity were obtained. As the presented approach is very generic we show that high resolution mass spectrometry in combination with PRM and QPrEST™ internal standards is a versatile tool for protein quantitation across multispecies.

  20. Screening for exogenous androgen anabolic steroids in human hair by liquid chromatography/orbitrap-high resolution mass spectrometry.

    Science.gov (United States)

    Strano-Rossi, Sabina; Castrignanò, Erika; Anzillotti, Luca; Odoardi, Sara; De-Giorgio, Fabio; Bermejo, Ana; Pascali, Vincenzo L

    2013-09-02

    A method for the screening of various anabolic steroids and their esters in human hair, based on liquid-chromatography-high resolution mass spectrometry using an Exactive benchtop Orbitrap mass spectrometer, has been set up and validated. This method involved methanolic incubation of 30 mg of hair and analysis of the relevant extract in HPLC using a C18 column. The mass detector, with nominal resolving power of 100,000, operated in full scan mode in APCI under positive ionization mode. Analytes were identified by exact mass, correspondence of isotopic cluster and retention times. The limits of detection obtained varied from 10 to 50 pg mg(-1), and limits of quantitation were 0.5 ng mg(-1) for all compounds. The method was linear for all analytes in the ranges from the LOQ to 6 ng mg(-1), giving correlation coefficients >0.99 for all analytes. Also accuracy (intended as %E) and repeatability (%CV) were always lower than 15%. Specificity was assessed by analysing ten blank samples and fifteen samples from polidrug abusers. This method was applied to a real-life case, resulting in the identification of testosterone undecanoate in the hair of a suspect. The analyte identity was confirmed by the analysis of its in-source fragmentation and comparison to a certified standard. Thanks to the scan acquisition, this method also enables retrospective re-analysis of the acquired datafile in case a further analyte needs to be screened. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. High-throughput untargeted screening of veterinary drug residues and metabolites in tilapia using high resolution orbitrap mass spectrometry.

    Science.gov (United States)

    Jia, Wei; Chu, Xiaogang; Chang, James; Wang, Perry G; Chen, Ying; Zhang, Feng

    2017-03-08

    An analytical method was developed and validated for simultaneous analysis of one hundred and thirty-seven veterinary drug residues and metabolites from sixteen different classes in tilapia utilizing an improved fully non-targeted way of data acquisition with fragmentation. The automated on-line extraction procedure was achieved in a simple disposable pipet extraction. Ultrahigh-performance liquid chromatography and electrospray ionization quadrupole Orbitrap high-resolution mass spectrometry (UHPLC Q-Orbitrap) was used for the separation and detection of all the analytes. The methodology was validated by taking into consideration the guidelines specified in European SANCO/12571/2013 Guideline 2013 and Commission Decision 2002/657/EC. The extraction recoveries ranged from 81% to 111%. The limits of decision ranged from 0.01 to 2.73 μg kg -1 and the detection capabilities ranged from 0.01 to 4.73 μg kg -1 . The one hundred and thirty-seven compounds behave dynamic 0.1-500 μg kg -1 , with correlation coefficient >0.99. The fully non-targeted data acquisition way improves both sensitivity and selectivity for the fragments, which is beneficial for screening performance and identification capability. This validated method has been successfully applied on screening of veterinary drug residues and metabolites in muscle of tilapia, an important and intensively produced fish in aquaculture. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Liquid chromatography-high resolution mass spectrometry for the analysis of phytochemicals in vegetal-derived food and beverages.

    Science.gov (United States)

    La Barbera, Giorgia; Capriotti, Anna Laura; Cavaliere, Chiara; Montone, Carmela Maria; Piovesana, Susy; Samperi, Roberto; Zenezini Chiozzi, Riccardo; Laganà, Aldo

    2017-10-01

    The recent years witnessed a change in the perception of nutrition. Diet does not only provide nutrients to meet the metabolic requirements of the body, but it also constitutes an active way for the consumption of compounds beneficial for human health. Fruit and vegetables are an excellent source of such compounds, thus the growing interest in characterizing phytochemical sources, structures and activities. Given the interest for phytochemicals in food, the development of advanced and suitable analytical techniques for their identification is fundamental for the advancement of food research. In this review, the state of the art of phytochemical research in food plants is described, starting from sample preparation, throughout extract clean-up and compound separation techniques, to the final analysis, considering both qualitative and quantitative investigations. In this regard, from an analytical point of view, fruit and vegetable extracts are complex matrices, which greatly benefit from the use of modern hyphenated techniques, in particular from the combination of high performance liquid chromatography separation and high resolution mass spectrometry, powerful tools which are being increasingly used in the recent years. Therefore, selected applications to real samples are presented and discussed, in particular for the analysis of phenols, polyphenols and phenolic acids. Finally, some hot points are discussed, such as waste characterization for high value-compounds recovery and the untargeted metabolomics approach. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Metabolic profile modifications in milk after enrofloxacin administration studied by liquid chromatography coupled with high resolution mass spectrometry.

    Science.gov (United States)

    Junza, A; Saurina, J; Barrón, D; Minguillón, C

    2016-08-19

    High resolution accurate mass spectrometry (HRMS) operating in full scan MS mode was used in the search and identification of metabolites in raw milk from cows medicated with enrofloxacin. Data consisting of m/z features were taken throughout the entire chromatogram of milk samples from medicated animals and were compared with blank samples. Twenty six different compounds were identified. Some of them were attributed to structures related to enrofloxacin while others were dipeptides or tripeptides. Additionally, enrofloxacin was administered in a controlled treatment for three days. Milk was collected daily from the first day of treatment and until four days after in the search for the identified compounds. The obtained data were chemometrically treated by Principal Component Analysis. Samples were classified by this method into three different groups corresponding to days 1-2, day 3 and days 4-7 considering the different concentration profile evolution of metabolites during the days studied. Tentative metabolic pathways were designed to rationalize the presence of the newly identified compounds. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Current applications of high-resolution mass spectrometry for the analysis of new psychoactive substances: a critical review.

    Science.gov (United States)

    Pasin, Daniel; Cawley, Adam; Bidny, Sergei; Fu, Shanlin

    2017-10-01

    The proliferation of new psychoactive substances (NPS) in recent years has resulted in the development of numerous analytical methods for the detection and identification of known and unknown NPS derivatives. High-resolution mass spectrometry (HRMS) has been identified as the method of choice for broad screening of NPS in a wide range of analytical contexts because of its ability to measure accurate masses using data-independent acquisition (DIA) techniques. Additionally, it has shown promise for non-targeted screening strategies that have been developed in order to detect and identify novel analogues without the need for certified reference materials (CRMs) or comprehensive mass spectral libraries. This paper reviews the applications of HRMS for the analysis of NPS in forensic drug chemistry and analytical toxicology. It provides an overview of the sample preparation procedures in addition to data acquisition, instrumental analysis, and data processing techniques. Furthermore, it gives an overview of the current state of non-targeted screening strategies with discussion on future directions and perspectives of this technique. Graphical Abstract Missing the bullseye - a graphical respresentation of non-targeted screening. Image courtesy of Christian Alonzo.

  5. Determination of sulfur in coal and ash slurry by high-resolution continuum source electrothermal molecular absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Nakadi, Flávio V.; Rosa, Lilian R.; Veiga, Márcia A.M.S. da, E-mail: mamsveiga@ffclrp.usp.br

    2013-10-01

    We propose a procedure for the determination of sulfur in coal slurries by high resolution continuum source electrothermal molecular absorption spectrometry. The slurry, whose concentration is 1 mg mL{sup −1}, was prepared by mixing 50 mg of the sample with 5% v/v nitric acid and 0.04% m/v Triton X-100 and was homogenized manually. It sustained good stability. The determination was performed via CS molecular absorption at 257.592 nm, and the optimized vaporization temperature was 2500 °C. The accuracy of the method was ensured by analysis of certified reference materials SRM 1632b (trace elements in coal) and SRM 1633b (coal fly ash) from the National Institute of Standards and Technology, using external calibration with aqueous standards prepared in the same medium and used as slurry. We achieved good agreement with the certified reference materials within 95% confidence interval, LOD of 0.01% w/w, and RSD of 6%, which confirms the potential of the proposed method. - Highlights: • HR-CS ET MAS as a technique to determine sulfur in coal and ash • Utilization of (coal and coal fly ash) slurry as a sample preparation • Simple and fast method, which uses external calibration with aqueous standards without chemical modifier.

  6. Analysis of volatile thiols in alcoholic beverages by simultaneous derivatization/extraction and liquid chromatography-high resolution mass spectrometry.

    Science.gov (United States)

    Vichi, Stefania; Cortés-Francisco, Nuria; Caixach, Josep

    2015-05-15

    A simultaneous derivatization/extraction method followed by liquid chromatography-electrospray-high resolution mass spectrometry for the determination of volatile thiols in hydroalcoholic matrixes was optimized and used to identify and quantify volatile thiols in wine and beer samples. The method was evaluated in terms of sensitivity, precision, accuracy and selectivity. The experimental LOQs of eleven thiols tested ranged between 0.01 ng/L and 10 ng/L. Intra-day relative standard deviation (RSD) was in general lower than 10% and inter-day RSD ranged between 10% and 30%. Recovery in the model and real matrixes ranged from 45% to 129%. The method was then applied for the analysis of four white wines and six beers. Five out of the eleven reference thiols were identified and quantified in the samples analyzed. The non-target approach, carried out by monitoring the diagnostic ion at m/z 275.9922 [C13H10ONSe](+) in the fragmentation spectrum, allowed detecting, in the same samples, fourteen non-target thiols. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Ultra-high performance liquid chromatography tandem high-resolution mass spectrometry study of tricyclazole photodegradation products in water.

    Science.gov (United States)

    Gosetti, Fabio; Chiuminatto, Ugo; Mazzucco, Eleonora; Mastroianni, Rita; Bolfi, Bianca; Marengo, Emilio

    2015-06-01

    This paper reports the study of the photodegradation reactions that tricyclazole can naturally undergo, under the action of sunlight, in aqueous solutions of standard tricyclazole and of the commercial BEAM(TM) formulation. The analyses are carried out by ultra-high performance liquid chromatography technique coupled with high-resolution tandem mass spectrometry. Analysis of both tricyclazole and BEAM(TM) water solutions undergone to hydrolysis does not evidence new chromatographic peaks with respect to the not treated solutions. On the contrary, analysis of the same samples subjected to sunlight irradiation shows a decreased intensity of tricyclazole signal and the presence of new chromatographic peaks. Two photodegradation products of tricyclazole have been identified, one of which has been also quantified, being the commercial standard available. The pattern is similar for the solutions of the standard fungicide and of the BEAM(TM) formulation. The results obtained from eco-toxicological tests show that toxicity of tricyclazole standard solutions is greater than that of the irradiated ones, whereas toxicity levels of all the BEAM(TM) solutions investigated (non-irradiated, irradiated, and hydrolyzed) are comparable and lower than those shown by tricyclazole standard solutions. Experiments performed in paddy water solution show that there is no difference in the degradation products formed.

  8. Novel approaches in analysis of Fusarium mycotoxins in cereals employing ultra performance liquid chromatography coupled with high resolution mass spectrometry

    International Nuclear Information System (INIS)

    Zachariasova, M.; Lacina, O.; Malachova, A.; Kostelanska, M.; Poustka, J.; Godula, M.; Hajslova, J.

    2010-01-01

    Rapid, simple and cost-effective analytical methods with performance characteristics matching regulatory requirements are needed for effective control of occurrence of Fusarium toxins in cereals and cereal-based products to which they might be transferred during processing. Within this study, two alternative approaches enabling retrospective data analysis and identification of unknown signals in sample extracts have been implemented and validated for determination of 11 major Fusarium toxins. In both cases, ultra-high performance liquid chromatography (U-HPLC) coupled with high resolution mass spectrometry (HR MS) was employed. 13 C isotopically labeled surrogates as well as matrix-matched standards were employed for quantification. As far as time of flight mass analyzer (TOF-MS) was a detection tool, the use of modified QuEChERS (quick easy cheap effective rugged and safe) sample preparation procedure, widely employed in multi-pesticides residue analysis, was shown as an optimal approach to obtain low detection limits. The second challenging alternative, enabling direct analysis of crude extract, was the use of mass analyzer based on Orbitrap technology. In addition to demonstration of full compliance of the new methods with Commission Regulation (EC) No. 401/2006, also their potential to be used for confirmatory purposes according to Commission Decision 2002/657/EC has been critically assessed.

  9. Determination of total sulfur in agricultural samples by high-resolution continuum source flame molecular absorption spectrometry.

    Science.gov (United States)

    Virgilio, Alex; Raposo, Jorge L; Cardoso, Arnaldo A; Nóbrega, Joaquim A; Gomes Neto, José A

    2011-03-23

    The usefulness of molecular absorption was investigated for the determination of total sulfur (S) in agricultural samples by high-resolution continuum source flame molecular absorption spectrometry. The lines for CS at 257.595, 257.958, and 258.056 nm and for SH at 323.658, 324.064, and 327.990 nm were evaluated. Figures of merit, such as linear dynamic range, sensitivity, linear correlation, characteristic concentration, limit of detection, and precision, were established. For selected CS lines, wavelength-integrated absorbance equivalent to 3 pixels, analytical curves in the 100-2500 mg L(-1) (257.595 nm), 250-2000 mg L(-1) (257.958 nm), and 250-5000 mg L(-1) (258.056 nm) ranges with a linear correlation coefficient better than 0.9980 were obtained. Results were in agreement at a 95% confidence level (paired t test) with those obtained by gravimetry. Recoveries of S in fungicide and fertilizer samples were within the 84-109% range, and the relative standard deviation (n=12) was typically <5%.

  10. Detection of silver nanoparticles in parsley by solid sampling high-resolution-continuum source atomic absorption spectrometry.

    Science.gov (United States)

    Feichtmeier, Nadine S; Leopold, Kerstin

    2014-06-01

    In this work, we present a fast and simple approach for detection of silver nanoparticles (AgNPs) in biological material (parsley) by solid sampling high-resolution-continuum source atomic absorption spectrometry (HR-CS AAS). A novel evaluation strategy was developed in order to distinguish AgNPs from ionic silver and for sizing of AgNPs. For this purpose, atomisation delay was introduced as significant indication of AgNPs, whereas atomisation rates allow distinction of 20-, 60-, and 80-nm AgNPs. Atomisation delays were found to be higher for samples containing silver ions than for samples containing silver nanoparticles. A maximum difference in atomisation delay normalised by the sample weight of 6.27 ± 0.96 s mg(-1) was obtained after optimisation of the furnace program of the AAS. For this purpose, a multivariate experimental design was used varying atomisation temperature, atomisation heating rate and pyrolysis temperature. Atomisation rates were calculated as the slope of the first inflection point of the absorbance signals and correlated with the size of the AgNPs in the biological sample. Hence, solid sampling HR-CS AAS was proved to be a promising tool for identifying and distinguishing silver nanoparticles from ionic silver directly in solid biological samples.

  11. [Determination of hydroxyproline in liver tissue by hydrophilic interaction chromatography-quadrupole/electrostatic field orbitrap high resolution mass spectrometry].

    Science.gov (United States)

    Liu, Wei; Qi, Shenglan; Xu, Ying; Xiao, Zhun; Fu, Yadong; Chen, Jiamei; Yang, Tao; Liu, Ping

    2017-12-08

    A method for the determination of hydroxyproline (Hyp) in liver tissue of mice by hydrophilic interaction chromatography-quadrupole/electrostatic field orbitrap high resolution mass spectrometry (HILIC-HRMS) was developed. The liver tissue samples of normal mice and liver fibrosis mice induced by carbon tetrachloride were hydrolyzed by concentrated hydrochloric acid. After filtrated and diluted by solution, the diluent was separated on an Hypersil GOLD HILIC column (100 mm×2.1 mm, 3 μm). Water-acetonitrile (28:72, v/v)were used as the mobile phases with isocratic elution. Finally, the target analytes were detected in positive model by HRMS equipped with an electrospray ionization source. The linear range of hydroxyproline was from 0.78 to 100.00 μg/L with the correlation coefficient ( R 2 ) of 0.9983. The limit of quantification was 0.78 μg/L. By detecting the spiked samples, the recoveries were in the range of 97.4%-100.9% with the relative standard deviations (RSDs) between 1.4% and 2.0%. In addition, comparison of the measurement results by this method and the chloramine T method was proceeded. It was found that the linear correlation between the two methods was very good, and the Pearson correlation coefficient was 0.927. And this method had simpler operation procedure and higher accuracy than chloramine T method. This method can be used for the quick determination of hydroxyproline in liver tissue samples.

  12. Nontargeted Screening Method for Illegal Additives Based on Ultrahigh-Performance Liquid Chromatography-High-Resolution Mass Spectrometry.

    Science.gov (United States)

    Fu, Yanqing; Zhou, Zhihui; Kong, Hongwei; Lu, Xin; Zhao, Xinjie; Chen, Yihui; Chen, Jia; Wu, Zeming; Xu, Zhiliang; Zhao, Chunxia; Xu, Guowang

    2016-09-06

    Identification of illegal additives in complex matrixes is important in the food safety field. In this study a nontargeted screening strategy was developed to find illegal additives based on ultrahigh-performance liquid chromatography-high-resolution mass spectrometry (UHPLC-HRMS). First, an analytical method for possible illegal additives in complex matrixes was established including fast sample pretreatment, accurate UHPLC separation, and HRMS detection. Second, efficient data processing and differential analysis workflow were suggested and applied to find potential risk compounds. Third, structure elucidation of risk compounds was performed by (1) searching online databases [Metlin and the Human Metabolome Database (HMDB)] and an in-house database which was established at the above-defined conditions of UHPLC-HRMS analysis and contains information on retention time, mass spectra (MS), and tandem mass spectra (MS/MS) of 475 illegal additives, (2) analyzing fragment ions, and (3) referring to fragmentation rules. Fish was taken as an example to show the usefulness of the nontargeted screening strategy, and six additives were found in suspected fish samples. Quantitative analysis was further carried out to determine the contents of these compounds. The satisfactory application of this strategy in fish samples means that it can also be used in the screening of illegal additives in other kinds of food samples.

  13. Development of an improved high resolution mass spectrometry based multi-residue method for veterinary drugs in various food matrices.

    Science.gov (United States)

    Kaufmann, A; Butcher, P; Maden, K; Walker, S; Widmer, M

    2011-08-26

    Multi-residue methods for veterinary drugs or pesticides in food are increasingly often based on ultra performance liquid chromatography (UPLC) coupled to high resolution mass spectrometry (HRMS). Previous available time of flight (TOF) technologies, showing resolutions up to 15,000 full width at half maximum (FWHM), were not sufficiently selective for monitoring low residue concentrations in difficult matrices (e.g. hormones in tissue or antibiotics in honey). The approach proposed in this paper is based on a single stage Orbitrap mass spectrometer operated at 50,000 FWHM. Extracts (liver and kidney) which were produced according to a validated multi-residue method (time of flight detection based) could not be analyzed by Orbitrap because of extensive signal suppression. This required the improvement of established extraction and clean-up procedures. The introduced, more extensive deproteinzation steps and dedicated instrumental settings successfully eliminated these detrimental suppression effects. The reported method, covering more than 100 different veterinary dugs, was validated according to the EU Commission Decision 2002/657/EEC. Validated matrices include muscle, kidney, liver, fish and honey. Significantly better performance parameters (e.g. linearity, reproducibility and detection limits) were obtained when comparing the new method with the older, TOF based method. These improvements are attributed to the higher resolution (50,000 versus 12,000 FWHM) and the superior mass stability of the of the Orbitrap over the previously utilized TOF instrument. Copyright © 2010 Elsevier B.V. All rights reserved.

  14. Oligomers, organosulfates, and nitrooxy organosulfates in rainwater identified by ultra-high resolution electrospray ionization FT-ICR mass spectrometry

    Directory of Open Access Journals (Sweden)

    K. E. Altieri

    2009-04-01

    Full Text Available Wet deposition is an important removal mechanism for atmospheric organic matter, and a potentially important input for receiving ecosystems, yet less than 50% of rainwater organic matter is considered chemically characterized. Precipitation samples collected in New Jersey, USA, were analyzed by negative ion ultra-high resolution electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS. Elemental compositions of 552 unique molecular species were determined in the mass range 50–500 Da in the rainwater. Four main groups of organic compounds were identified: compounds containing carbon, hydrogen, and oxygen (CHO only, sulfur (S containing CHOS compounds, nitrogen (N containing CHON compounds, and S- and N- containing CHONS compounds. Organic acids commonly identified in precipitation were detected in the rainwater. Within the four main groups of compounds detected in the rainwater, oligomers, organosulfates, and nitrooxy-organosulfates were assigned based on elemental formula comparisons. The majority of the compounds identified are products of atmospheric reactions and are known contributors to secondary organic aerosol (SOA formed from gas phase, aerosol phase, and in-cloud reactions in the atmosphere. It is suggested that the large uncharacterized component of SOA is the main contributor to the large uncharacterized component of rainwater organic matter.

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

    KAUST Repository

    Kyriacou, Bianca

    2014-03-01

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

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

    KAUST Repository

    Kyriacou, Bianca; Moore, Katie L.; Paterson, David J.; De Jonge, Martin Daly; Howard, Daryl Lloyd; Stangoulis, James Constantine R; Tester, Mark A.; Lombi, E.; Johnson, Alexander A T

    2014-01-01

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

  17. A sediment extraction and cleanup method for wide-scope multitarget screening by liquid chromatography-high-resolution mass spectrometry.

    Science.gov (United States)

    Massei, Riccardo; Byers, Harry; Beckers, Liza-Marie; Prothmann, Jens; Brack, Werner; Schulze, Tobias; Krauss, Martin

    2018-01-01

    Previous studies on organic sediment contaminants focused mainly on a limited number of highly hydrophobic micropollutants accessible to gas chromatography using nonpolar, aprotic extraction solvents. The development of liquid chromatography-high-resolution mass spectrometry (LC-HRMS) permits the spectrum of analysis to be expanded to a wider range of more polar and ionic compounds present in sediments and allows target, suspect, and nontarget screening to be conducted with high sensitivity and selectivity. In this study, we propose a comprehensive multitarget extraction and sample preparation method for characterization of sediment pollution covering a broad range of physicochemical properties that is suitable for LC-HRMS screening analysis. We optimized pressurized liquid extraction, cleanup, and sample dilution for a target list of 310 compounds. Finally, the method was tested on sediment samples from a small river and its tributaries. The results show that the combination of 100 °C for ethyl acetate-acetone (50:50, neutral extract) followed by 80 °C for acetone-formic acid (100:1, acidic extract) and methanol-10 mM sodium tetraborate in water (90:10, basic extract) offered the best extraction recoveries for 287 of 310 compounds. At a spiking level of 1 μg mL -1 , we obtained satisfactory cleanup recoveries for the neutral extract-(93 ± 23)%-and for the combined acidic/basic extracts-(42 ± 16)%-after solvent exchange. Among the 69 compounds detected in environmental samples, we successfully quantified several pharmaceuticals and polar pesticides.

  18. Determination of trace concentrations of chlorine in aqueous solutions by high-resolution continuum source graphite furnace molecular absorption spectrometry

    Science.gov (United States)

    Machyňák, Ľubomír; Čacho, František; Němeček, Martin; Beinrohr, Ernest

    2016-11-01

    Trace concentrations of total chlorine were determined by means of molecular absorption of indium mono-chloride (InCl) at 267.217 nm using high-resolution continuum source graphite furnace molecular absorption spectrometry. The effects of chemical modifiers and the amount of In on the sensitivity and accuracy were investigated. The optimum pyrolysis and vaporization temperatures were 600 °C and 1400 °C, respectively. The limit of detection and characteristic mass were found to be 0.10 ng and 0.21 ng, respectively. Potential non-spectral and spectral interferences were tested for various metals and non-metals at concentrations up to 50 mg L- 1 and for phosphoric, sulphuric and nitric acids. No spectral interferences were observed. Significant non-spectral interferences were observed with F, Br, and I at concentrations higher than 1 mg L- 1, 5 mg L- 1 and 25 mg L- 1, respectively, which is probably caused by formation of competitive indium halogen molecules. Higher concentrations of mineral acids depressed the signal owing to the formation of volatile HCl. The calibration curve was linear in the range between 0.3 and 10 ng with a correlation coefficient of R = 0.993. The elaborated method was used for the chlorine determination in various waters and a drug sample.

  19. Possibilities of High Resolution Inductively Coupled Plasma Optical Emission Spectrometry in the Determination of Trace Elements in Environmental Materials

    Directory of Open Access Journals (Sweden)

    Nikolaya Velitchkova

    2013-01-01

    Full Text Available This paper presents new quantitative data for the spectral interferences obtained by high resolution 40.68 MHz radial viewing inductively coupled plasma optical emission spectrometry (HR-ICP-OES in the determination of Zn, Cd, Sb, Cu, Mn, Pb, Sn, Cr, U, and Ba in environmental materials in the presence of a complex matrix, containing Al, Ca, Fe, Mg, and Ti. The -concept for quantification of spectral interferences was used. The optimum line selection for trace analysis of a variety of multicomponent matrices requires the choice of prominent lines, which are free or negligibly influenced by line interference problems. The versatility of -concept as basic methodology was experimentally demonstrated in the determination of trace of elements in soil and drinking water. The detection limits are lower in comparison with corresponding threshold concentration levels for soil and drinking water in accordance with environmental regulations. This paper shows the possibilities of present day ICP-OES equipment in the direct determination of trace elements (without preconcentration of impurities in environmental samples.

  20. Study of Grape Polyphenols by Liquid Chromatography-High-Resolution Mass Spectrometry (UHPLC/QTOF and Suspect Screening Analysis

    Directory of Open Access Journals (Sweden)

    Riccardo Flamini

    2015-01-01

    Full Text Available Suspect screening analysis is a targeted metabolomics method in which the identification of compounds relies on specific available information, such as their molecular formula and isotopic pattern. This method, coupled to liquid chromatography-high-resolution mass spectrometry, is effective in the study of grape metabolomics, in particular for characterization of flavonols, stilbene derivatives, and anthocyanins. For identification of compounds expected in the samples, a new database of putative compounds was expressly constructed by using the molecular information on potential metabolites of grape and wine from the literature and other electronic databases. Currently, this database contains around 1,100 compounds. The method allows identification of several hundred grape metabolites with two analyses (positive and negative ionization modes, and performing of data reprocessing using “untargeted” algorithms also provided the identification of some flavonols and resveratrol trimers and tetramers in grape for the first time. This approach can be potentially used in the study of metabolomics of varieties of other plant species.

  1. Line width and line shape analysis in the inductively coupled plasma by high resolution Fourier transform spectrometry

    International Nuclear Information System (INIS)

    Faires, L.M.; Palmer, B.A.; Brault, J.W.

    1984-01-01

    High resolution Fourier transform spectrometry has been used to perform line width and line shape analysis of eighty-one iron I emision lines in the spectral range 290 to 390nm originating in the normal analytical zone of an inductively coupled plasma. Computer programs using non-linear least squares fitting techniques for line shape analysis were applied to the fully resolved spectra to determine Gaussian and Lorentzian components of the total observed line width. The effect of noise in the spectrum on the precision of the line fitting technique was assessed, and the importance of signal to noise ratio for line shape analysis is discussed. Translational (Doppler) temperatures were calculated from the Gaussian components of the line width and were found to be on the order of 6300 0 K. The excitation temperature of iron I was also determined from the same spectral data by the spectroscopic slope method based on the Einstein-Boltzmann expression for spectral intensity and was found to be on the order of 4700 0 K. 31 references

  2. Compton suppression gamma ray spectrometry

    International Nuclear Information System (INIS)

    Landsberger, S.; Iskander, F.Y.; Niset, M.; Heydorn, K.

    2002-01-01

    In the past decade there have been many studies to use Compton suppression methods in routine neutron activation analysis as well as in the traditional role of low level gamma ray counting of environmental samples. On a separate path there have been many new PC based software packages that have been developed to enhance photopeak fitting. Although the newer PC based algorithms have had significant improvements, they still suffer from being effectively used in weak gamma ray lines in natural samples or in neutron activated samples that have very high Compton backgrounds. We have completed a series of experiments to show the usefulness of Compton suppression. As well we have shown the pitfalls when using Compton suppression methods for high counting deadtimes as in the case of neutron activated samples. We have also investigated if counting statistics are the same both suppressed and normal modes. Results are presented in four separate experiments. (author)

  3. Multi-detection of corticosteroids in sports doping and veterinary control using high-resolution liquid chromatography/time-of-flight mass spectrometry

    NARCIS (Netherlands)

    Touber, M.E.; Engelen, M.C.; Georgakopoulus, C.; Rhijn, van J.A.; Nielen, M.W.F.

    2007-01-01

    A liquid chromatography/time-of-flight mass spectrometry (LC/TOFMS) method was developed using the latest high-resolution LC column technology, the ultra performance liquid chromatography (UPLC (TM)), and electrospray ionization (ESI) in the positive ion mode. Gradient UPLC separation conditions

  4. High-resolution line-scan analysis of resin-embedded sediments using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS)

    NARCIS (Netherlands)

    Hennekam, Rick; Jilbert, Tom; Mason, Paul R D; de Lange, Gert J.; Reichart, Gert Jan

    2015-01-01

    Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) line-scanning is a promising technique for producing high-resolution (μm-scale) geochemical records on resin-embedded sediments. However, this approach has not yet been thoroughly tested on sediment samples of known elemental

  5. High-resolution line-scan analysis of resin-embedded sediments using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS)

    NARCIS (Netherlands)

    Hennekam, R.; Jilbert, T.; de Lange, G.J.; Reichart, G.J.

    2015-01-01

    Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) line-scanning is a promising technique for producing high-resolution (µm-scale) geochemical records on resin-embedded sediments. However, this approach has not yet been thoroughly tested on sediment samples of known elemental

  6. Decon2LS: An open-source software package for automated processing and visualization of high resolution mass spectrometry data.

    Science.gov (United States)

    Jaitly, Navdeep; Mayampurath, Anoop; Littlefield, Kyle; Adkins, Joshua N; Anderson, Gordon A; Smith, Richard D

    2009-03-17

    Data generated from liquid chromatography coupled to high-resolution mass spectrometry (LC-MS)-based studies of a biological sample can contain large amounts of biologically significant information in the form of proteins, peptides, and metabolites. Interpreting this data involves inferring the masses and abundances of biomolecules injected into the instrument. Because of the inherent complexity of mass spectral patterns produced by these biomolecules, the analysis is significantly enhanced by using visualization capabilities to inspect and confirm results. In this paper we describe Decon2LS, an open-source software package for automated processing and visualization of high-resolution MS data. Drawing extensively on algorithms developed over the last ten years for ICR2LS, Decon2LS packages the algorithms as a rich set of modular, reusable processing classes for performing diverse functions such as reading raw data, routine peak finding, theoretical isotope distribution modelling, and deisotoping. Because the source code is openly available, these functionalities can now be used to build derivative applications in relatively fast manner. In addition, Decon2LS provides an extensive set of visualization tools, such as high performance chart controls. With a variety of options that include peak processing, deisotoping, isotope composition, etc, Decon2LS supports processing of multiple raw data formats. Deisotoping can be performed on an individual scan, an individual dataset, or on multiple datasets using batch processing. Other processing options include creating a two dimensional view of mass and liquid chromatography (LC) elution time features, generating spectrum files for tandem MS data, creating total intensity chromatograms, and visualizing theoretical peptide profiles. Application of Decon2LS to deisotope different datasets obtained across different instruments yielded a high number of features that can be used to identify and quantify peptides in the

  7. Decon2LS: An open-source software package for automated processing and visualization of high resolution mass spectrometry data

    Directory of Open Access Journals (Sweden)

    Anderson Gordon A

    2009-03-01

    Full Text Available Abstract Background Data generated from liquid chromatography coupled to high-resolution mass spectrometry (LC-MS-based studies of a biological sample can contain large amounts of biologically significant information in the form of proteins, peptides, and metabolites. Interpreting this data involves inferring the masses and abundances of biomolecules injected into the instrument. Because of the inherent complexity of mass spectral patterns produced by these biomolecules, the analysis is significantly enhanced by using visualization capabilities to inspect and confirm results. In this paper we describe Decon2LS, an open-source software package for automated processing and visualization of high-resolution MS data. Drawing extensively on algorithms developed over the last ten years for ICR2LS, Decon2LS packages the algorithms as a rich set of modular, reusable processing classes for performing diverse functions such as reading raw data, routine peak finding, theoretical isotope distribution modelling, and deisotoping. Because the source code is openly available, these functionalities can now be used to build derivative applications in relatively fast manner. In addition, Decon2LS provides an extensive set of visualization tools, such as high performance chart controls. Results With a variety of options that include peak processing, deisotoping, isotope composition, etc, Decon2LS supports processing of multiple raw data formats. Deisotoping can be performed on an individual scan, an individual dataset, or on multiple datasets using batch processing. Other processing options include creating a two dimensional view of mass and liquid chromatography (LC elution time features, generating spectrum files for tandem MS data, creating total intensity chromatograms, and visualizing theoretical peptide profiles. Application of Decon2LS to deisotope different datasets obtained across different instruments yielded a high number of features that can be used to

  8. High-Resolution Mass Spectrometry and Molecular Characterization of Aqueous Photochemistry Products of Common Types of Secondary Organic Aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Romonosky, Dian E.; Laskin, Alexander; Laskin, Julia; Nizkorodov, Sergey

    2015-03-19

    A significant fraction of atmospheric organic compounds is predominantly found in condensed phases, such as aerosol particles and cloud droplets. Many of these compounds are photolabile and can degrade through direct photolysis or indirect photooxidation processes on time scales that are comparable to the typical lifetimes of aqueous droplets (hours) and particles (days). This paper presents a systematic investigation of the molecular level composition and the extent of aqueous photochemical processing in different types of secondary organic aerosol (SOA) from biogenic and anthropogenic precursors including α-pinene, β-pinene, β-myrcene, d- limonene, α-humulene, 1,3,5-trimethylbenzene, and guaiacol, oxidized by ozone (to simulate a remote atmosphere) or by OH in the presence of NOx (to simulate an urban atmosphere). Chamber- and flow tube-generated SOA samples were collected, extracted in a methanol/water solution, and photolyzed for 1 h under identical irradiation conditions. In these experiments, the irradiation was equivalent to about 3-8 h of exposure to the sun in its zenith. The molecular level composition of the dissolved SOA was probed before and after photolysis with direct-infusion electrospray ionization high-resolution mass spectrometry (ESI-HR-MS). The mass spectra of unphotolyzed SOA generated by ozone oxidation of monoterpenes showed qualitatively similar features, and contained largely overlapping subsets of identified compounds. The mass spectra of OH/NOx generated SOA had more unique visual appearance, and indicated a lower extent of products overlap. Furthermore, the fraction of nitrogen containing species (organonitrates and nitroaromatics) was highly sensitive to the SOA precursor. These observations suggest that attribution of high-resolution mass spectra in field SOA samples to specific SOA precursors should be more straightforward under OH/NOx oxidation conditions compared to the ozone driven oxidation. Comparison of the SOA constituents

  9. In-Situ Assay Of Transuranic Radionuclides In The Vadose Zone Using High-Resolution Spectral Gamma Logging - A Hanford Case Study

    International Nuclear Information System (INIS)

    Rohay, V.J.; Henwood, P.; McCain, R.

    2009-01-01

    High-resolution spectral gamma logging in steel-cased boreholes is used to detect and quantify transuranic radionuclides in the subsurface. Pu-239, Pu-241, Am-241, and Np-237 are identified based on characteristic decay gammas. Typical minimum detectable levels are on the order of 20 to 40 nCi/g. In intervals of high transuranic concentrations, gamma rays from other sources may complicate analysis and interpretation. Gamma rays detected in the borehole may originate from three sources: decay of the parent transuranic radionuclide or a daughter; alpha interactions; and interactions with neutrons resulting from either spontaneous fission or alpha particle interactions.

  10. Performance of gamma spectrometry counting system

    International Nuclear Information System (INIS)

    Yii Mei Wo; Maziah Mahmud

    2007-01-01

    Gamma spectrometry counting system widely used as tool to measure qualitative and quantitative gamma-ray emitters in a sample. Container size, sample to detector distance, sample volume are well known factors that affecting the quality of measurement. However, factor such as the age of the system was not been reported. Therefore, the objective of this study is to find out how the age factor affecting the quality of the measurement. From this study, it is found that when the age of the system increased, the system tends to have higher lower limit of detection and poorer linearity showing that age factor do affecting the quality of measurement. (Author)

  11. High-Resolution Measurement of the {sup 4}He({gamma},n) Reaction in the Giant Resonance Region

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, Bjoern

    2003-03-01

    A comprehensive near-threshold {sup 4}He(gamma,n) absolute cross section measurement has been performed at the high-resolution tagged-photon facility MAX-lab located in Lund, Sweden. The 20 < Eg < 45 MeV tagged photons (covering the Giant Dipole Resonance energy region) were directed towards a liquid {sup 4}He target, and knocked-out neutrons were detected in a pair of 60 cm x 60 cm vetoed NE213A liquid scintillator arrays. The intense and varying charge-neutral experimental backgrounds were carefully quantified and removed from the data using a precision fitting procedure. Eight average laboratory angles (30, 45, 60, 75, 90, 105, 120, and 135 deg) were investigated for eight photon energy bins (25, 27, 29, 31, 35, 36, 39, and 41 MeV), resulting in 64 differential cross sections. These angular distributions were integrated to produce total cross sections as a function of photon energy. The resulting cross sections peak at 1.9 mb at a photon energy of 27 MeV, and fall off to a near-constant value of 1.1 mb by 36 MeV. Further, they are in excellent agreement with those measured by Sims et al. using tagged photons in the Quasi-Deuteron energy region. Overall, the results favor modern theoretical models which are based upon a charge-symmetric nucleon-nucleon force, in marked contrast to the recommendations made by Calarco et al. in 1983 based on the sparse {sup 4}He(gamma,n) data available at the time.

  12. A study of radiocaesium concentrations in the Irish marine environment using a high resolution gamma-ray spectrometer

    International Nuclear Information System (INIS)

    Vidal-Quadras, A.; Mitchell, P.I.

    1983-01-01

    A selection of marine samples collected in the vicinity of Dublin Bay on the East Coast of Ireland and Galway Bay on the West Coast have been analyzed with a high resolution Compton suppression spectrometer designed for the analysis of low-level environmental samples. Radiocaesium levels in these samples are compared and some preliminary conclusions presented. The principal components of the spectrometer, which is described in detail, are (I) an upward-locking Ge(Li) detector mounted in a special NPR-type cryostat, (II) active shielding in the form of a well detector fashioned from NE102A scintillator and a NaI(T1) detector, (III) an anti-Compton analyzer and (IV) a multichannel analyzer. The multichannel analyzer is interfaced with a 32K microcomputer to a Digital VAX-11/780 computer where up-to-date gamma spectroscopy techniques are employed for the deconvolution of spectra, search and identification of each line and estimation of the activity of each radionuclide. (author)

  13. Programme in Basic-Applesoft language for microcomputer to analyse pulse spectra from a high-resolution gamma ray system

    International Nuclear Information System (INIS)

    Nascimento Filho, V.F. do; Marques, D.A.; Pessenda, L.C.R.; Barros Ferraz, E.S. de; Nadai, E.A. de; Sao Paulo Univ., Piracicaba

    1988-01-01

    A programme in BASIC-Applesoft language has been developed for low cost microcomputer to analyze spectra from a high-resolution gamma-ray system (high-purity germanium and 4096 channels analyzer). Data is received by the microcomputer directly from analyzer (4 min) or keyboard and shown on video (4 min) or printed (9,7 min). Graphics of parts of the spectrum can be either shown on video (a cursor is used to identify peaks) or printed. The peak search, centroid, energy, net photopeak area, standard deviation and relative standard deviation are included in the programme (5 min), besides filing of data in flexible disk (1,3 min). The programme was used on a 12 h real-time detection in Marinelli beaker of 1265 g sandy soil sample (Ref-Yellow Latosol, 0-3 cm layer). Thirty-one peaks from U-238 and Th-232 daughters were analyzed (rsd less than 20%), besides natural K-40 and artificial Cs-137, from fallout. (author) [pt

  14. Applications of Fourier Transform Ion Cyclotron Resonance (FT-ICR) and Orbitrap Based High Resolution Mass Spectrometry in Metabolomics and Lipidomics

    Science.gov (United States)

    Ghaste, Manoj; Mistrik, Robert; Shulaev, Vladimir

    2016-01-01

    Metabolomics, along with other “omics” approaches, is rapidly becoming one of the major approaches aimed at understanding the organization and dynamics of metabolic networks. Mass spectrometry is often a technique of choice for metabolomics studies due to its high sensitivity, reproducibility and wide dynamic range. High resolution mass spectrometry (HRMS) is a widely practiced technique in analytical and bioanalytical sciences. It offers exceptionally high resolution and the highest degree of structural confirmation. Many metabolomics studies have been conducted using HRMS over the past decade. In this review, we will explore the latest developments in Fourier transform mass spectrometry (FTMS) and Orbitrap based metabolomics technology, its advantages and drawbacks for using in metabolomics and lipidomics studies, and development of novel approaches for processing HRMS data. PMID:27231903

  15. Screening for exogenous androgen anabolic steroids in human hair by liquid chromatography/orbitrap-high resolution mass spectrometry

    International Nuclear Information System (INIS)

    Strano-Rossi, Sabina; Castrignanò, Erika; Anzillotti, Luca; Odoardi, Sara; De-Giorgio, Fabio; Bermejo, Ana; Pascali, Vincenzo L.

    2013-01-01

    Graphical abstract: -- Highlights: •LC–HRMS screening method for the detection of a variety of anabolics in hair. •Detection of unmetabolized anabolic steroids and their esters in hair matrix by simple keratin pretreatment. •Identification of target compounds by retention time, accurate mass and isotopic cluster. •Quantitative determination of detected compounds. •Possibility to a retrospective re-analysis of the acquired datafile in case a further analyte is to be screened. -- Abstract: A method for the screening of various anabolic steroids and their esters in human hair, based on liquid-chromatography–high resolution mass spectrometry using an Exactive benchtop Orbitrap mass spectrometer, has been set up and validated. This method involved methanolic incubation of 30 mg of hair and analysis of the relevant extract in HPLC using a C18 column. The mass detector, with nominal resolving power of 100,000, operated in full scan mode in APCI under positive ionization mode. Analytes were identified by exact mass, correspondence of isotopic cluster and retention times. The limits of detection obtained varied from 10 to 50 pg mg −1 , and limits of quantitation were 0.5 ng mg −1 for all compounds. The method was linear for all analytes in the ranges from the LOQ to 6 ng mg −1 , giving correlation coefficients >0.99 for all analytes. Also accuracy (intended as %E) and repeatability (%CV) were always lower than 15%. Specificity was assessed by analysing ten blank samples and fifteen samples from polidrug abusers. This method was applied to a real-life case, resulting in the identification of testosterone undecanoate in the hair of a suspect. The analyte identity was confirmed by the analysis of its in-source fragmentation and comparison to a certified standard. Thanks to the scan acquisition, this method also enables retrospective re-analysis of the acquired datafile in case a further analyte needs to be screened

  16. Annotation of the human serum metabolome by coupling three liquid chromatography methods to high-resolution mass spectrometry.

    Science.gov (United States)

    Boudah, Samia; Olivier, Marie-Françoise; Aros-Calt, Sandrine; Oliveira, Lydie; Fenaille, François; Tabet, Jean-Claude; Junot, Christophe

    2014-09-01

    This work aims at evaluating the relevance and versatility of liquid chromatography coupled to high resolution mass spectrometry (LC/HRMS) for performing a qualitative and comprehensive study of the human serum metabolome. To this end, three different chromatographic systems based on a reversed phase (RP), hydrophilic interaction chromatography (HILIC) and a pentafluorophenylpropyl (PFPP) stationary phase were used, with detection in both positive and negative electrospray modes. LC/HRMS platforms were first assessed for their ability to detect, retain and separate 657 metabolite standards representative of the chemical families occurring in biological fluids. More than 75% were efficiently retained in either one LC-condition and less than 5% were exclusively retained by the RP column. These three LC/HRMS systems were then evaluated for their coverage of serum metabolome. The combination of RP, HILIC and PFPP based LC/HRMS methods resulted in the annotation of about 1328 features in the negative ionization mode, and 1358 in the positive ionization mode on the basis of their accurate mass and precise retention time in at least one chromatographic condition. Less than 12% of these annotations were shared by the three LC systems, which highlights their complementarity. HILIC column ensured the greatest metabolome coverage in the negative ionization mode, whereas PFPP column was the most effective in the positive ionization mode. Altogether, 192 annotations were confirmed using our spectral database and 74 others by performing MS/MS experiments. This resulted in the formal or putative identification of 266 metabolites, among which 59 are reported for the first time in human serum. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Determination of BMAA and three alkaloid cyanotoxins in lake water using dansyl chloride derivatization and high-resolution mass spectrometry.

    Science.gov (United States)

    Roy-Lachapelle, Audrey; Solliec, Morgan; Sauvé, Sébastien

    2015-07-01

    A new analytical method was developed for the detection of alkaloid cyanotoxins in harmful algal blooms. The detection of the nonproteinogenic amino acid β-N-methylamino-L-alanine (BMAA) and two of its conformation isomers, 2,4-diaminobutyric acid (DAB) and N-(2-aminoethyl) glycine (AEG), as well as three alkaloid cyanotoxins, anatoxin-a (ANA-a), cylindrospermopsin (CYN), and saxitoxin (STX), is presented. The use of a chemical derivatization with dansyl chloride (DNS) allows easier separation with reversed phase liquid chromatography. Detection with high-resolution mass spectrometry (HRMS) with the Q-Exactive enables high selectivity with specific fragmentation as well as exact mass detection, reducing considerably the possibilities of isobaric interferences. Previous to analysis, a solid phase extraction (SPE) step is used for purification and preconcentration. After DNS derivatization, samples are submitted to ultra high-performance liquid chromatography coupled with heated electrospray ionisation and the Q-Exactive mass spectrometer (UHPLC-HESI-HRMS). With an internal calibration using isotopically-labeled DAB-D3, the method was validated with good linearity (R (2)  > 0.998), and method limits of detection and quantification (MLD and MLQ) for target compounds ranged from 0.007 to 0.01 μg L(-1) and from 0.02 to 0.04 μg L(-1), respectively. Accuracy and within-day/between-days variation coefficients were below 15%. SPE recovery values ranged between 86 and 103%, and matrix effects recovery values ranged between 75 and 96%. The developed analytical method was successfully validated with 12 different lakes samples, and concentrations were found ranging between 0.009 and 0.3 μg L(-1) except for STX which was not found in any sample.

  18. An integrated strategy for in vivo metabolite profiling using high-resolution mass spectrometry based data processing techniques

    International Nuclear Information System (INIS)

    Guo, Jian; Zhang, Minli; Elmore, Charles S.; Vishwanathan, Karthick

    2013-01-01

    Graphical abstract: -- Highlights: •Profiling the metabolites of model compounds in rats using high resolution mass spectrometry based data processing techniques. •Demonstrating an integrated strategy in vivo metabolite profiling using data mining tools. •Unusual metabolites generated via thiazole-ring opening were characterized based on processed LC–MS.data. -- Abstract: An ongoing challenge of drug metabolite profiling is to detect and identify unknown or low-level metabolites in complex biological matrices. Here we present a generic strategy for metabolite detection using multiple accurate-mass-based data processing tools via the analysis of rat samples of two model drug candidates, AZD6280 and AZ12488024. First, the function of isotopic pattern recognition was proved to be highly effective in the detection of metabolites derived from [ 14 C]-AZD6280 that possesses a distinct isotopic pattern. The metabolites revealed using this approach were in excellent qualitative correlation to those observed in radiochromatograms. Second, the effectiveness of accurate mass based untargeted data mining tools such as background subtraction, mass defect filtering, or a data mining package (MZmine) used for metabolomic analysis in detection of metabolites of [ 14 C]-AZ12488024 in rat urine, feces, bile and plasma samples was examined and a total of 33 metabolites of AZ12488024 were detected. Among them, at least 16 metabolites were only detected by the aid of the data mining packages and not via radiochromatograms. New metabolic pathways such as S-oxidation and thiomethylation reactions occurring on the thiazole ring were proposed based on the processed data. The results of these experiments also demonstrated that accurate mass-based mass defect filtering (MDF) and data mining techniques used in metabolomics are complementary and can be valuable tools for delineating low-level metabolites in complex matrices. Furthermore, the application of distinct multiple data

  19. Screening halogenated environmental contaminants in biota based on isotopic pattern and mass defect provided by high resolution mass spectrometry profiling

    Energy Technology Data Exchange (ETDEWEB)

    Cariou, Ronan, E-mail: laberca@oniris-nantes.fr; Omer, Elsa; Léon, Alexis; Dervilly-Pinel, Gaud; Le Bizec, Bruno

    2016-09-14

    In the present work, we addressed the question of global seeking/screening organohalogenated compounds in a large panel of complex biological matrices, with a particular focus on unknown chemicals that may be considered as potential emerging hazards. A fishing strategy was developed based on untargeted profiling among full scan acquisition datasets provided by high resolution mass spectrometry. Since large datasets arise from such profiling, filtering useful information stands as a central question. In this way, we took advantage of the exact mass differences between Cl and Br isotopes. Indeed, our workflow involved an innovative Visual Basic for Applications script aiming at pairing features according to this mass difference, in order to point out potential organohalogenated clusters, preceded by an automated peak picking step based on the centWave function (xcms package of open access R programming environment). Then, H/Cl-scale mass defect plots were used to visualize the datasets before and after filtering. The filtering script was successfully applied to a dataset generated upon liquid chromatography coupled to ESI(−)-HRMS measurement from one eel muscle extract, allowing for realistic manual investigations of filtered clusters. Starting from 9789 initial obtained features, 1994 features were paired in 589 clusters. Hexabromocyclododecane, chlorinated paraffin series and various other compounds have been identified or tentatively identified, allowing thus broad screening of organohalogenated compounds in this extract. Although realistic, manual review of paired clusters remains time consuming and much effort should be devoted to automation. - Highlights: • We address the screening of halogenated compounds in large Full Scan HRMS datasets. • The workflow involves peak picking, pairing script and review of paired features. • The pairing script is based on exact mass differences between Cl and Br isotopes. • H/Cl scale mass defect plots are used to

  20. Direct surface analysis coupled to high-resolution mass spectrometry reveals heterogeneous composition of the cuticle of Hibiscus trionum petals.

    Science.gov (United States)

    Giorio, Chiara; Moyroud, Edwige; Glover, Beverley J; Skelton, Paul C; Kalberer, Markus

    2015-10-06

    Plant cuticle, which is the outermost layer covering the aerial parts of all plants including petals and leaves, can present a wide range of patterns that, combined with cell shape, can generate unique physical, mechanical, or optical properties. For example, arrays of regularly spaced nanoridges have been found on the dark (anthocyanin-rich) portion at the base of the petals of Hibiscus trionum. Those ridges act as a diffraction grating, producing an iridescent effect. Because the surface of the distal white region of the petals is smooth and noniridescent, a selective chemical characterization of the surface of the petals on different portions (i.e., ridged vs smooth) is needed to understand whether distinct cuticular patterns correlate with distinct chemical compositions of the cuticle. In the present study, a rapid screening method has been developed for the direct surface analysis of Hibiscus trionum petals using liquid extraction surface analysis (LESA) coupled with high-resolution mass spectrometry. The optimized method was used to characterize a wide range of plant metabolites and cuticle monomers on the upper (adaxial) surface of the petals on both the white/smooth and anthocyanic/ridged regions, and on the lower (abaxial) surface, which is entirely smooth. The main components detected on the surface of the petals are low-molecular-weight organic acids, sugars, and flavonoids. The ridged portion on the upper surface of the petal is enriched in long-chain fatty acids, which are constituents of the wax fraction of the cuticle. These compounds were not detected on the white/smooth region of the upper petal surface or on the smooth lower surface.

  1. Electrospray Ionization with High-Resolution Mass Spectrometry as a Tool for Lignomics: Lignin Mass Spectrum Deconvolution

    Science.gov (United States)

    Andrianova, Anastasia A.; DiProspero, Thomas; Geib, Clayton; Smoliakova, Irina P.; Kozliak, Evguenii I.; Kubátová, Alena

    2018-05-01

    The capability to characterize lignin, lignocellulose, and their degradation products is essential for the development of new renewable feedstocks. Electrospray ionization high-resolution time-of-flight mass spectrometry (ESI-HR TOF-MS) method was developed expanding the lignomics toolkit while targeting the simultaneous detection of low and high molecular weight (MW) lignin species. The effect of a broad range of electrolytes and various ionization conditions on ion formation and ionization effectiveness was studied using a suite of mono-, di-, and triarene lignin model compounds as well as kraft alkali lignin. Contrary to the previous studies, the positive ionization mode was found to be more effective for methoxy-substituted arenes and polyphenols, i.e., species of a broadly varied MW structurally similar to the native lignin. For the first time, we report an effective formation of multiply charged species of lignin with the subsequent mass spectrum deconvolution in the presence of 100 mmol L-1 formic acid in the positive ESI mode. The developed method enabled the detection of lignin species with an MW between 150 and 9000 Da or higher, depending on the mass analyzer. The obtained M n and M w values of 1500 and 2500 Da, respectively, were in good agreement with those determined by gel permeation chromatography. Furthermore, the deconvoluted ESI mass spectrum was similar to that obtained with matrix-assisted laser desorption/ionization (MALDI)-HR TOF-MS, yet featuring a higher signal-to-noise ratio. The formation of multiply charged species was confirmed with ion mobility ESI-HR Q-TOF-MS. [Figure not available: see fulltext.

  2. Screening halogenated environmental contaminants in biota based on isotopic pattern and mass defect provided by high resolution mass spectrometry profiling

    International Nuclear Information System (INIS)

    Cariou, Ronan; Omer, Elsa; Léon, Alexis; Dervilly-Pinel, Gaud; Le Bizec, Bruno

    2016-01-01

    In the present work, we addressed the question of global seeking/screening organohalogenated compounds in a large panel of complex biological matrices, with a particular focus on unknown chemicals that may be considered as potential emerging hazards. A fishing strategy was developed based on untargeted profiling among full scan acquisition datasets provided by high resolution mass spectrometry. Since large datasets arise from such profiling, filtering useful information stands as a central question. In this way, we took advantage of the exact mass differences between Cl and Br isotopes. Indeed, our workflow involved an innovative Visual Basic for Applications script aiming at pairing features according to this mass difference, in order to point out potential organohalogenated clusters, preceded by an automated peak picking step based on the centWave function (xcms package of open access R programming environment). Then, H/Cl-scale mass defect plots were used to visualize the datasets before and after filtering. The filtering script was successfully applied to a dataset generated upon liquid chromatography coupled to ESI(−)-HRMS measurement from one eel muscle extract, allowing for realistic manual investigations of filtered clusters. Starting from 9789 initial obtained features, 1994 features were paired in 589 clusters. Hexabromocyclododecane, chlorinated paraffin series and various other compounds have been identified or tentatively identified, allowing thus broad screening of organohalogenated compounds in this extract. Although realistic, manual review of paired clusters remains time consuming and much effort should be devoted to automation. - Highlights: • We address the screening of halogenated compounds in large Full Scan HRMS datasets. • The workflow involves peak picking, pairing script and review of paired features. • The pairing script is based on exact mass differences between Cl and Br isotopes. • H/Cl scale mass defect plots are used to

  3. Comparative analysis of native and permethylated human milk oligosaccharides by liquid chromatography coupled to high resolution mass spectrometry.

    Science.gov (United States)

    Oursel, Stéphanie; Cholet, Sophie; Junot, Christophe; Fenaille, François

    2017-12-15

    Human milk oligosaccharides (HMOs) represent the third most abundant components of milk after lactose and lipids. HMOs are indigestible by the suckling infant but can act as prebiotics and have significant biological functions regarding the organism defense against pathogens (such as bacteria or viruses) by preventing interactions with their receptors. Although constituted of only five distinct monosaccharide building blocks, HMOs are highly structurally diverse compounds with many co-existing structural isomers. Here we report the development and comparison of two distinct glycomic platforms based on liquid chromatography coupled to high resolution mass spectrometry (LC-MS) for analyzing HMOs. We have implemented and thoroughly compared the LC-MS of permethylated and native HMOs on reversed phase (RP) and porous graphitic carbon (PGC) columns for their ability to resolve the natural heterogeneity of milk oligosaccharides at the highest sensitivity. Our data essentially underlines the usefulness of analyzing HMOs as permethylated derivatives especially for getting more precise structural information at high sensitivity. For instance, permethylation annihilates gas-phase fucose migration during MS/MS experiments, thus facilitating spectra interpretation and giving access to relevant information regarding oligosaccharide branching and isomer distinction. At the opposite, LC-MS profiling of native HMOs (using PGC) in milk performed best in terms of detected species, while also being much faster in terms of sample preparation. Although less efficient than PGC chromatography, RPLC proved successful for separating pairs of permethylated isomeric HMOs. A key advantage of RP over PGC liquid chromatography is that retention times can be correlated to molecular weights, which can greatly facilitate further HMO identification using retention time prediction. Altogether these data lead us to think that LC-MS analysis of native HMOs (using PGC) can be used as first

  4. Screening for exogenous androgen anabolic steroids in human hair by liquid chromatography/orbitrap-high resolution mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Strano-Rossi, Sabina, E-mail: sabina.stranorossi@rm.unicatt.it [Institute of Legal Medicine, Catholic University of Sacred Heart, L.go F. Vito, 1, 00168 Rome (Italy); Castrignanò, Erika; Anzillotti, Luca; Odoardi, Sara; De-Giorgio, Fabio [Institute of Legal Medicine, Catholic University of Sacred Heart, L.go F. Vito, 1, 00168 Rome (Italy); Bermejo, Ana [Institute of Legal Medicine, University of Santiago de Compostela, Av S. Francisco s/n, Santiago de Compostela (Spain); Pascali, Vincenzo L. [Institute of Legal Medicine, Catholic University of Sacred Heart, L.go F. Vito, 1, 00168 Rome (Italy)

    2013-09-02

    Graphical abstract: -- Highlights: •LC–HRMS screening method for the detection of a variety of anabolics in hair. •Detection of unmetabolized anabolic steroids and their esters in hair matrix by simple keratin pretreatment. •Identification of target compounds by retention time, accurate mass and isotopic cluster. •Quantitative determination of detected compounds. •Possibility to a retrospective re-analysis of the acquired datafile in case a further analyte is to be screened. -- Abstract: A method for the screening of various anabolic steroids and their esters in human hair, based on liquid-chromatography–high resolution mass spectrometry using an Exactive benchtop Orbitrap mass spectrometer, has been set up and validated. This method involved methanolic incubation of 30 mg of hair and analysis of the relevant extract in HPLC using a C18 column. The mass detector, with nominal resolving power of 100,000, operated in full scan mode in APCI under positive ionization mode. Analytes were identified by exact mass, correspondence of isotopic cluster and retention times. The limits of detection obtained varied from 10 to 50 pg mg{sup −1}, and limits of quantitation were 0.5 ng mg{sup −1} for all compounds. The method was linear for all analytes in the ranges from the LOQ to 6 ng mg{sup −1}, giving correlation coefficients >0.99 for all analytes. Also accuracy (intended as %E) and repeatability (%CV) were always lower than 15%. Specificity was assessed by analysing ten blank samples and fifteen samples from polidrug abusers. This method was applied to a real-life case, resulting in the identification of testosterone undecanoate in the hair of a suspect. The analyte identity was confirmed by the analysis of its in-source fragmentation and comparison to a certified standard. Thanks to the scan acquisition, this method also enables retrospective re-analysis of the acquired datafile in case a further analyte needs to be screened.

  5. Hydrophilic interaction liquid chromatography coupled to high-resolution mass spectrometry to determine artificial sweeteners in environmental waters.

    Science.gov (United States)

    Salas, Daniela; Borrull, Francesc; Fontanals, Núria; Marcé, Rosa Maria

    2015-06-01

    Artificial sweeteners are food additives employed as sugar substitutes which are now considered to be emerging organic contaminants. In the present study, a method is developed for the determination of a group of artificial sweeteners in environmental waters. Considering the polar and hydrophilic character of these compounds, hydrophilic interaction liquid chromatography is proposed for their separation as an alternative to traditional reversed-phase liquid chromatography. Two stationary phases with different chemistry were compared for this purpose. For the detection of the analytes, high-resolution mass spectrometry (Orbitrap) was employed to take advantage of its benefits in terms of reliable quantification and confirmation for the measurement of accurate masses. Solid-phase extraction was chosen as the sample treatment, in which the extract in a mixture of NH4OH:MeOH:ACN (1:4:15) was directly injected into the chromatographic system, simplifying the analytical procedure. The optimized method was validated on river and waste water samples. For example, in the case of effluent water samples, limits of detection ranged from 0.002 to 0.7 μg/L and limits of quantification ranged from 0.004 to 1.5 μg/L. Apparent (whole method) recoveries ranged from 57 to 74% with intra-day precision (%RSD, n = 5) ranging from 6 to 25%. The method was successfully applied to water samples from different rivers in Catalonia and different waste water treatment plants in Tarragona. Acesulfame, cyclamate, saccharine and sucralose were found in several samples.

  6. Practical application of in silico fragmentation based residue screening with ion mobility high-resolution mass spectrometry.

    Science.gov (United States)

    Kaufmann, Anton; Butcher, Patrick; Maden, Kathry; Walker, Stephan; Widmer, Mirjam

    2017-07-15

    A screening concept for residues in complex matrices based on liquid chromatography coupled to ion mobility high-resolution mass spectrometry LC/IMS-HRMS is presented. The comprehensive four-dimensional data (chromatographic retention time, drift time, mass-to-charge and ion abundance) obtained in data-independent acquisition (DIA) mode was used for data mining. An in silico fragmenter utilizing a molecular structure database was used for suspect screening, instead of targeted screening with reference substances. The utilized data-independent acquisition mode relies on the MS E concept; where two constantly alternating HRMS scans (low and high fragmentation energy) are acquired. Peak deconvolution and drift time alignment of ions from the low (precursor ion) and high (product ion) energy scan result in relatively clean product ion spectra. A bond dissociation in silico fragmenter (MassFragment) supplied with mol files of compounds of interest was used to explain the observed product ions of each extracted candidate component (chromatographic peak). Two complex matrices (fish and bovine liver extract) were fortified with 98 veterinary drugs. Out of 98 screened compounds 94 could be detected with the in silico based screening approach. The high correlation among drift time and m/z value of equally charged ions was utilized for an orthogonal filtration (ranking). Such an orthogonal ion mobility based filter removes multiply charged ions (e.g. peptides and proteins from the matrix) as well as noise and artefacts. Most significantly, this filtration dramatically reduces false positive findings but hardly increases false negative findings. The proposed screening approach may offer new possibilities for applications where reference compounds are hardly or not at all commercially available. Such areas may be the analysis of metabolites of drugs, pyrrolizidine alkaloids, marine toxins, derivatives of sildenafil or novel designer drugs (new psychoactive substances

  7. Validation of the Mass-Extraction-Window for Quantitative Methods Using Liquid Chromatography High Resolution Mass Spectrometry.

    Science.gov (United States)

    Glauser, Gaétan; Grund, Baptiste; Gassner, Anne-Laure; Menin, Laure; Henry, Hugues; Bromirski, Maciej; Schütz, Frédéric; McMullen, Justin; Rochat, Bertrand

    2016-03-15

    A paradigm shift is underway in the field of quantitative liquid chromatography-mass spectrometry (LC-MS) analysis thanks to the arrival of recent high-resolution mass spectrometers (HRMS). The capability of HRMS to perform sensitive and reliable quantifications of a large variety of analytes in HR-full scan mode is showing that it is now realistic to perform quantitative and qualitative analysis with the same instrument. Moreover, HR-full scan acquisition offers a global view of sample extracts and allows retrospective investigations as virtually all ionized compounds are detected with a high sensitivity. In time, the versatility of HRMS together with the increasing need for relative quantification of hundreds of endogenous metabolites should promote a shift from triple-quadrupole MS to HRMS. However, a current "pitfall" in quantitative LC-HRMS analysis is the lack of HRMS-specific guidance for validated quantitative analyses. Indeed, false positive and false negative HRMS detections are rare, albeit possible, if inadequate parameters are used. Here, we investigated two key parameters for the validation of LC-HRMS quantitative analyses: the mass accuracy (MA) and the mass-extraction-window (MEW) that is used to construct the extracted-ion-chromatograms. We propose MA-parameters, graphs, and equations to calculate rational MEW width for the validation of quantitative LC-HRMS methods. MA measurements were performed on four different LC-HRMS platforms. Experimentally determined MEW values ranged between 5.6 and 16.5 ppm and depended on the HRMS platform, its working environment, the calibration procedure, and the analyte considered. The proposed procedure provides a fit-for-purpose MEW determination and prevents false detections.

  8. Determination of silicon and aluminum in silicon carbide nanocrystals by high-resolution continuum source graphite furnace atomic absorption spectrometry.

    Science.gov (United States)

    Dravecz, Gabriella; Bencs, László; Beke, Dávid; Gali, Adam

    2016-01-15

    The determination of Al contaminant and the main component Si in silicon carbide (SiC) nanocrystals with the size-distribution of 1-8nm dispersed in an aqueous solution was developed using high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS-GFAAS). The vaporization/atomization processes were investigated in a transversally heated graphite atomizer by evaporating solution samples of Al and Si preserved in various media (HCl, HNO3). For Si, the best results were obtained by applying a mixture of 5µg Pd plus 5µg Mg, whereas for Al, 10µg Mg (each as nitrate solution) was dispensed with the samples, but the results obtained without modifier were found to be better. This way a maximum pyrolysis temperature of 1200°C for Si and 1300°C for Al could be used, and the optimum (compromise) atomization temperature was 2400°C for both analytes. The Si and Al contents of different sized SiC nanocrystals, dispersed in aqueous solutions, were determined against aqueous (external) calibration standards. The correlation coefficients (R values) of the calibrations were found to be 0.9963 for Si and 0.9991 for Al. The upper limit of the linear calibration range was 2mg/l Si and 0.25mg/l Al. The limit of detection was 3µg/l for Si and 0.5µg/l for Al. The characteristic mass (m0) was calculated to be 389pg Si and 6.4pg Al. The Si and Al content in the solution samples were found to be in the range of 1.0-1.7mg/l and 0.1-0.25mg/l, respectively. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Computer programs for data reduction and interpretation in plutonium and uranium analysis by gamma ray spectrometry

    International Nuclear Information System (INIS)

    Singh, R.K.; Moorthy, A.D.; Babbar, R.K.; Udagatti, S.V.

    1989-01-01

    Non destructive gamma ray have been developed for analysis of isotopic abundances and concentrations of plutonium and uranium in the respective product solutions of a reprocessing plant. The method involves analysis of gamma rays emitted from the sample and uses a multichannel analyser system. Data reduction and interpretation of these techniques are tedious and time consuming. In order to make it possible to use them in routine analysis, computer programs have been developed in HP-BASIC language which can be used in HP-9845B desktop computer. A set of programs, for plutonium estimation by high resolution gamma ray spectrometry and for on-line measurement of uranium by gamma ray spectrometry are described in this report. (author) 4 refs., 3 tabs., 6 figs

  10. Quantitative analysis of multiple high-resolution mass spectrometry images using chemometric methods: quantitation of chlordecone in mouse liver.

    Science.gov (United States)

    Mohammadi, Saeedeh; Parastar, Hadi

    2018-05-15

    In this work, a chemometrics-based strategy is developed for quantitative mass spectrometry imaging (MSI). In this regard, quantification of chlordecone as a carcinogenic organochlorinated pesticide (C10Cll0O) in mouse liver using the matrix-assisted laser desorption ionization MSI (MALDI-MSI) method is used as a case study. The MSI datasets corresponded to 1, 5 and 10 days of mouse exposure to the standard chlordecone in the quantity range of 0 to 450 μg g-1. The binning approach in the m/z direction is used to group high resolution m/z values and to reduce the big data size. To consider the effect of bin size on the quality of results, three different bin sizes of 0.25, 0.5 and 1.0 were chosen. Afterwards, three-way MSI data arrays (two spatial and one m/z dimensions) for seven standards and four unknown samples were column-wise augmented with m/z values as the common mode. Then, these datasets were analyzed using multivariate curve resolution-alternating least squares (MCR-ALS) using proper constraints. The resolved mass spectra were used for identification of chlordecone in the presence of a complex background and interference. Additionally, the augmented spatial profiles were post-processed and 2D images for each component were obtained in calibration and unknown samples. The sum of these profiles was utilized to set the calibration curve and to obtain the analytical figures of merit (AFOMs). Inspection of the results showed that the lower bin size (i.e., 0.25) provides more accurate results. Finally, the obtained results by MCR for three datasets were compared with those of gas chromatography-mass spectrometry (GC-MS) and MALDI-MSI. The results showed that the MCR-assisted method gives a higher amount of chlordecone than MALDI-MSI and a lower amount than GC-MS. It is concluded that a combination of chemometric methods with MSI can be considered as an alternative way for MSI quantification.

  11. Development of High Resolution Resonance Ionization Mass Spectrometry for Neutron Dosimetry Technique with93Nb(n,n'93mNb Reaction

    Directory of Open Access Journals (Sweden)

    Tomita Hideki

    2016-01-01

    Full Text Available We have proposed an advanced technique to measure the 93mNb yield precisely by Resonance Ionization Mass Spectrometry, instead of conventional characteristic X-ray spectroscopy. 93mNb-selective resonance ionization is achievable by distinguishing the hyperfine splitting of the atomic energy levels between 93Nb and 93mNb at high resolution. In advance of 93mNb detection, we could successfully demonstrate high resolution resonant ionization spectroscopy of stable 93Nb using an all solid-state, narrow-band and tunable Ti:Sapphire laser system operated at 1 kHz repetition rate.

  12. Applicability of hybrid linear ion trap-high resolution mass spectrometry and quadrupole-linear ion trap-mass spectrometry for mycotoxin analysis in baby food.

    Science.gov (United States)

    Rubert, Josep; James, Kevin J; Mañes, Jordi; Soler, Carla

    2012-02-03

    Recent developments in mass spectrometers have created a paradoxical situation; different mass spectrometers are available, each of them with their specific strengths and drawbacks. Hybrid instruments try to unify several advantages in one instrument. In this study two of wide-used hybrid instruments were compared: hybrid quadrupole-linear ion trap-mass spectrometry (QTRAP®) and the hybrid linear ion trap-high resolution mass spectrometry (LTQ-Orbitrap®). Both instruments were applied to detect the presence of 18 selected mycotoxins in baby food. Analytical parameters were validated according to 2002/657/CE. Limits of quantification (LOQs) obtained by QTRAP® instrument ranged from 0.45 to 45 μg kg⁻¹ while lower limits of quantification (LLOQs) values were obtained by LTQ-Orbitrap®: 7-70 μg kg⁻¹. The correlation coefficients (r) in both cases were upper than 0.989. These values highlighted that both instruments were complementary for the analysis of mycotoxin in baby food; while QTRAP® reached best sensitivity and selectivity, LTQ-Orbitrap® allowed the identification of non-target and unknowns compounds. Copyright © 2011 Elsevier B.V. All rights reserved.

  13. Development of high-resolution gamma detector using sub-mm GAGG crystals coupled to TSV-MPPC array

    International Nuclear Information System (INIS)

    Lipovec, A.; Shimazoe, K.; Takahashi, H.

    2016-01-01

    In this study a high-resolution gamma detector based on an array of sub-millimeter Ce:GAGG (Cerium doped Gd 3 Al 2 Ga 3 O 12 ) crystals read out by an array of surface-mount type of TSV-MPPC was developed. MPPC sensor from Hamamatsu which has a 26 by 26 mm 2 detector area with 64 channels was used. One channel has a 3 by 3 mm 2 photosensitive area with 50 μ m pitch micro cells. MPPC sensor provides 576 mm 2 sensing area and was used to decode 48 by 48 array with 0.4 by 0.4 by 20 mm 3 Ce:GAGG crystals of 500 μ m pitch. The base of the detector with the crystal module was mounted to a read out board which consists of charge division circuit, thus allowing for a read out of four channels to identify the position of the incident event on the board. The read out signals were amplified using charge sensitive amplifiers. The four amplified signals were digitized and analyzed to produce a position sensitive event. For the performance analysis a 137 Cs source was used. The produced events were used for flood histogram and energy analysis. The effects of the glass thickness between the Ce:GAGG and MPPC were analyzed using the experimental flood diagrams and Geant4 simulations. The glass between the scintillator and the detector allows the spread of the light over different channels and is necessary if the channel's sensitive area is bigger than the scintillator's area. The initial results demonstrate that this detector module is promising and could be used for applications requiring compact and high-resolution detectors. Experimental results show that the detectors precision increases using glass guide thickness of 1.35 mm and 1.85 mm; however the precision using 2.5 mm are practically the same as if using 0.8 mm or 1.0 mm glass guide thicknesses. In addition, simulations using Geant4 indicate that the light becomes scarcer if thicker glass is used, thus reducing the ability to indicate which crystal was targeted. When 2.5 mm glass thickness is used, the scarce

  14. Determination of silicon in biomass and products of pyrolysis process via high-resolution continuum source atomic absorption spectrometry.

    Science.gov (United States)

    Nakadi, Flávio V; Prodanov, Caroline; Boschetti, Wiliam; Vale, Maria Goreti R; Welz, Bernhard; de Andrade, Jailson B

    2018-03-01

    Thermochemical processes can convert the biomass into fuels, such as bio-oil. The biomass submitted to pyrolysis process, such as fibers, are generally rich in silicon, an element that can lead to damages in an engine when there is high concentration in a fuel. High-resolution continuum source atomic absorption spectrometry (HR-CS AAS) is an interesting alternative for Si determination in the products and byproducts of the pyrolysis process because, besides the flame (F) and graphite furnace (GF) atomizers, it has enhanced the application of direct analysis of solid samples (SS) within GF. This study aimed the development of methods to determine Si in biomass samples, their products and byproducts using HR-CS AAS. A high-resolution continuum source atomic absorption spectrometer contrAA 700 equipped with F and GF atomizers was used throughout the study. HR-CS F AAS (λ = 251.611nm, 1 detection pixel, N 2 O/C 2 H 2 flame) was used to evaluate Si content in biomass and ash, after a microwave-assisted acid digestion with HNO 3 and HF. HR-CS GF AAS (T pyr = 1400°C, T atom = 2650°C) has evaluated Si in pyrolysis water and bio-oil at 251.611nm, and in peach pit biomass and ash at 221.174nm using SS, both wavelengths with 1 detection pixel. Rhodium (300μg) was applied as permanent modifier and 10μgPd + 6μg Mg were pipetted onto the standards/samples at each analysis. Three different biomass samples were studied: palm tree fiber, coconut fiber and peach pit, and three certified reference materials (CRM) were used to verify the accuracy of the methods. The figures of merit were LOD 0.09-20mgkg -1 , and LOQ 0.3-20mgkg -1 , considering all the methods. There were no significant differences between the CRM certified values and the determined ones, using a Student t-test with a confidence interval of 95% (n = 5). Si concentration ranged from 0.11-0.92% mm -1 , 1.1-1.7mgkg -1 , 3.3-13mgkg -1 , and 0.41-1.4%mm -1 , in biomass, bio-oil, pyrolysis water and ash, respectively

  15. Sensitivity analysis of high resolution gamma-ray detection for safeguards monitoring at natural uranium conversion facilities

    Energy Technology Data Exchange (ETDEWEB)

    Dewji, S.A., E-mail: dewjisa@ornl.gov [Oak Ridge National Laboratory, PO Box 2008 MS-6335, Oak Ridge TN 37831 (United States); Georgia Institute of Technology, 770 State Street, Atlanta, GA 30332-0745 (United States); Croft, S. [Oak Ridge National Laboratory, PO Box 2008 MS-6335, Oak Ridge TN 37831 (United States); Hertel, N.E. [Oak Ridge National Laboratory, PO Box 2008 MS-6335, Oak Ridge TN 37831 (United States); Georgia Institute of Technology, 770 State Street, Atlanta, GA 30332-0745 (United States)

    2017-03-11

    Under the policies proposed by recent International Atomic Energy Agency (IAEA) circulars and policy papers, implementation of safeguards exists when any purified aqueous uranium solution or uranium oxides suitable for isotopic enrichment or fuel fabrication exists. Under IAEA Policy Paper 18, the starting point for nuclear material under safeguards was reinterpreted, suggesting that purified uranium compounds should be subject to safeguards procedures no later than the first point in the conversion process. In response to this technical need, a combination of simulation models and experimental measurements were employed in previous work to develop and validate gamma-ray nondestructive assay monitoring systems in a natural uranium conversion plant (NUCP). In particular, uranyl nitrate (UO{sub 2}(NO{sub 3}){sub 2}) solution exiting solvent extraction was identified as a key measurement point (KMP). Passive nondestructive assay techniques using high resolution gamma-ray spectroscopy were evaluated to determine their viability as a technical means for drawing safeguards conclusions at NUCPs, and if the IAEA detection requirements of 1 significant quantity (SQ) can be met in a timely manner. Building upon the aforementioned previous validation work on detector sensitivity to varying concentrations of uranyl nitrate via a series of dilution measurements, this work investigates detector response parameter sensitivities to gamma-ray signatures of uranyl nitrate. The full energy peak efficiency of a detection system is dependent upon the sample, geometry, absorption, and intrinsic efficiency parameters. Perturbation of these parameters translates into corresponding variations of the 185.7 keV peak area of the {sup 235}U in uranyl nitrate. Such perturbations in the assayed signature impact the quality or versatility of the safeguards conclusions drawn. Given the potentially high throughput of uranyl nitrate in NUCPs, the ability to assay 1 SQ of material requires

  16. Determination of total mercury for marine environmental monitoring studies by solid sampling continuum source high resolution atomic absorption spectrometry

    Science.gov (United States)

    Mandjukov, Petko; Orani, Anna Maria; Han, Eunmi; Vassileva, Emilia

    2015-01-01

    The most critical step in almost all commonly used analytical procedures for Hg determination is the sample preparation due to its extreme volatility. One of the possible solutions of this problem is the application of methods for direct analysis of solid samples. The possibilities for solid sampling high resolution continuum source atomic absorption spectrometry (HR CS AAS) determination of total mercury in various marine environmental samples e.g. sediments and biota are object of the present study. The instrumental parameters were optimized in order to obtain reproducible and interference free analytical signal. A calibration technique based on the use of solid standard certified reference materials similar to the nature of the analyzed sample was developed and applied to various CRMs and real samples. This technique allows simple and reliable evaluation of the uncertainty of the result and the metrological characteristics of the method. A validation approach in line with the requirements of ISO 17025 standard and Eurachem guidelines was followed. With this in mind, selectivity, working range (0.06 to 25 ng for biota and 0.025 to 4 ng for sediment samples, expressed as total Hg) linearity (confirmed by Student's t-test), bias (1.6-4.3%), repeatability (4-9%), reproducibility (9-11%), and absolute limit of detection (0.025 ng for sediment, 0.096 ng for marine biota) were systematically assessed using solid CRMs. The relative expanded uncertainty was estimated at 15% for sediment sample and 8.5% for marine biota sample (k = 2). Demonstration of traceability of measurement results is also presented. The potential of the proposed analytical procedure, based on solid sampling HR CS AAS technique was demonstrated by direct analysis of sea sediments form the Caribbean region and various CRMs. Overall, the use of solid sampling HR CS AAS permits obtaining significant advantages for the determination of this complex analyte in marine samples, such as straightforward

  17. Determination of total mercury for marine environmental monitoring studies by solid sampling continuum source high resolution atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Mandjukov, Petko; Orani, Anna Maria; Han, Eunmi; Vassileva, Emilia, E-mail: e.vasileva-veleva@iaea.org

    2015-01-01

    The most critical step in almost all commonly used analytical procedures for Hg determination is the sample preparation due to its extreme volatility. One of the possible solutions of this problem is the application of methods for direct analysis of solid samples. The possibilities for solid sampling high resolution continuum source atomic absorption spectrometry (HR CS AAS) determination of total mercury in various marine environmental samples e.g. sediments and biota are object of the present study. The instrumental parameters were optimized in order to obtain reproducible and interference free analytical signal. A calibration technique based on the use of solid standard certified reference materials similar to the nature of the analyzed sample was developed and applied to various CRMs and real samples. This technique allows simple and reliable evaluation of the uncertainty of the result and the metrological characteristics of the method. A validation approach in line with the requirements of ISO 17025 standard and Eurachem guidelines was followed. With this in mind, selectivity, working range (0.06 to 25 ng for biota and 0.025 to 4 ng for sediment samples, expressed as total Hg) linearity (confirmed by Student's t-test), bias (1.6–4.3%), repeatability (4–9%), reproducibility (9–11%), and absolute limit of detection (0.025 ng for sediment, 0.096 ng for marine biota) were systematically assessed using solid CRMs. The relative expanded uncertainty was estimated at 15% for sediment sample and 8.5% for marine biota sample (k = 2). Demonstration of traceability of measurement results is also presented. The potential of the proposed analytical procedure, based on solid sampling HR CS AAS technique was demonstrated by direct analysis of sea sediments form the Caribbean region and various CRMs. Overall, the use of solid sampling HR CS AAS permits obtaining significant advantages for the determination of this complex analyte in marine samples, such as

  18. Molecular composition of rainwater and aerosol during rain events in León, Spain, using high resolution mass spectrometry.

    Science.gov (United States)

    Fee, Anna

    2017-04-01

    Anna Fee (1), Markus Kalberer (1), Roberto Fraile (2), Amaya Castro (2), Ana. I. Calvo (2), Carlos Blanco-Alegre (2), Fernanda Oduber (2) and Mário Cerqueira (3). 1 Department of Chemistry, University of Cambridge, UK. 2 Department of Applied Chemistry and Physics, IMARENAB, University of León, Spain. 3 Department of Environmental Planning, University of Aveiro, Portugal. A wide range of atmospheric compounds which are present in rainwater are often also present in aerosol. They can be taken up during cloud droplet formation (in-cloud scavenging) or washed out during precipitation (below-cloud scavenging). Such compounds including aromatic hydrocarbons and organic nitrogen containing compounds are hazardous to health. In this study, the organic chemical composition of rainwater and aerosol from rain events in León, Spain, is being analysed using high resolution mass spectrometry. Collected rainwater along with high volume and low volume filters from rain events which occurred during spring, summer and winter of 2016 have been selected for analysis. Rainwater samples were prepared using Polymeric Reversed Phase Solid Phase Extraction (SPE) and filters have been extracted in water with and without SPE. Three different SPE polymer based sorbents were tested; one for extracting neutral compounds and two which are more suitable for extracting organic compounds containing sulphate and other polar functional groups. The sorbent for extracting neutral compounds was found to yield a higher number of compounds from the sample extraction than the other two varieties. Kendrick masses, Van Krevelen plots and carbon oxidation states have been investigated to identify compounds and patterns. Preliminary results show a predominance in peaks with O/C ratios between 0.2 and 0.7 and H/C ratios between 1 and 2 in both rain and aerosol samples which indicates substituted aromatic compounds. Cellulose material and fatty acids may also be present. The rain samples also have a

  19. Evaluation of gas chromatography – electron ionization – full scan high resolution Orbitrap mass spectrometry for pesticide residue analysis

    Energy Technology Data Exchange (ETDEWEB)

    Mol, Hans G.J., E-mail: hans.mol@wur.nl; Tienstra, Marc; Zomer, Paul

    2016-09-07

    Gas chromatography with electron ionization and full scan high resolution mass spectrometry with an Orbitrap mass analyzer (GC-EI-full scan Orbitrap HRMS) was evaluated for residue analysis. Pesticides in fruit and vegetables were taken as an example application. The relevant aspects for GC-MS based residue analysis, including the resolving power (15,000 to 120,000 FWHM at m/z 200), scan rate, dynamic range, selectivity, sensitivity, analyte identification, and utility of existing EI-libraries, are assessed and discussed in detail. The optimum acquisition conditions in full scan mode (m/z 50–500) were a resolving power of 60,000 and an automatic-gain-control target value of 3E6. These conditions provided (i) an optimum mass accuracy: within 2 ppm over a wide concentration range, with/without matrix, enabling the use of ±5 ppm mass extraction windows (ii) adequate scan speed: minimum 12 scans/peak, (iii) an intra-scan dynamic range sufficient to achieve LOD/LOQs ≤0.5 pg in fruit/vegetable matrices (corresponding to ≤0.5 μg kg{sup −1}) for most pesticides. EI-Orbitrap spectra were consistent over a very wide concentration range (5 orders) with good match values against NIST (EI-quadrupole) spectra. The applicability for quantitative residue analysis was verified by validation of 54 pesticides in three matrices (tomato, leek, orange) at 10 and 50 μg/kg. The method involved a QuEChERS-based extraction with a solvent switch into iso-octane, and 1 μL hot splitless injection into the GC-HRMS system. A recovery between 70 and 120% and a repeatability RSD <10% was obtained in most cases. Linearity was demonstrated for the range ≤5–250 μg kg{sup −1}. The pesticides could be identified according to the applicable EU criteria for GC-HRMS (SANTE/11945/2015). GC-EI-full scan Orbitrap HRMS was found to be highly suited for quantitative pesticide residue analysis. The potential of qualitative screening to extend the scope makes it an attractive

  20. Evaluation of gas chromatography – electron ionization – full scan high resolution Orbitrap mass spectrometry for pesticide residue analysis

    International Nuclear Information System (INIS)

    Mol, Hans G.J.; Tienstra, Marc; Zomer, Paul

    2016-01-01

    Gas chromatography with electron ionization and full scan high resolution mass spectrometry with an Orbitrap mass analyzer (GC-EI-full scan Orbitrap HRMS) was evaluated for residue analysis. Pesticides in fruit and vegetables were taken as an example application. The relevant aspects for GC-MS based residue analysis, including the resolving power (15,000 to 120,000 FWHM at m/z 200), scan rate, dynamic range, selectivity, sensitivity, analyte identification, and utility of existing EI-libraries, are assessed and discussed in detail. The optimum acquisition conditions in full scan mode (m/z 50–500) were a resolving power of 60,000 and an automatic-gain-control target value of 3E6. These conditions provided (i) an optimum mass accuracy: within 2 ppm over a wide concentration range, with/without matrix, enabling the use of ±5 ppm mass extraction windows (ii) adequate scan speed: minimum 12 scans/peak, (iii) an intra-scan dynamic range sufficient to achieve LOD/LOQs ≤0.5 pg in fruit/vegetable matrices (corresponding to ≤0.5 μg kg"−"1) for most pesticides. EI-Orbitrap spectra were consistent over a very wide concentration range (5 orders) with good match values against NIST (EI-quadrupole) spectra. The applicability for quantitative residue analysis was verified by validation of 54 pesticides in three matrices (tomato, leek, orange) at 10 and 50 μg/kg. The method involved a QuEChERS-based extraction with a solvent switch into iso-octane, and 1 μL hot splitless injection into the GC-HRMS system. A recovery between 70 and 120% and a repeatability RSD <10% was obtained in most cases. Linearity was demonstrated for the range ≤5–250 μg kg"−"1. The pesticides could be identified according to the applicable EU criteria for GC-HRMS (SANTE/11945/2015). GC-EI-full scan Orbitrap HRMS was found to be highly suited for quantitative pesticide residue analysis. The potential of qualitative screening to extend the scope makes it an attractive alternative to

  1. High-resolution continuum source electrothermal atomic absorption spectrometry: Linearization of the calibration curves within a broad concentration range

    Energy Technology Data Exchange (ETDEWEB)

    Katskov, Dmitri, E-mail: katskovda@tut.ac.za [Tshwane University of Technology, Chemistry Department, Pretoria 0001 (South Africa); Hlongwane, Miranda [Tshwane University of Technology, Chemistry Department, Pretoria 0001 (South Africa); Heitmann, Uwe [German Aerospace Center, Rose-Luxemburg Str. 2, 10178 Berlin (Germany); Florek, Stefan [ISAS-Leibniz-Institut fuer Analytische Wissenschaften e.V., Albert-Einstein-Str. 9,12489 Berlin (Germany)

    2012-05-15

    The calculation algorithm suggested provides linearization of the calibration curves in high-resolution continuum source electrothermal atomic absorption spectrometry. The algorithm is based on the modification of the function wavelength-integrated absorbance vs. concentration of analyte vapor in the absorption volume. According to the suggested approach, the absorption line is represented by a triangle for low and trapezium for high analyte vapor concentration in the absorption volume. The respective semi-empirical formulas include two linearization parameters, which depend on properties of the absorption line and characteristics of the atomizer and spectrometer. The parameters can be approximately evaluated from the theory and determined in practice from the original broad-range calibration curve. The parameters were found and the proposed calculation algorithm verified in the experiments on direct determination of Ag, Cd, Cu, Fe, Mn and Pb in the solutions within a concentration ranges from 0.15 to 625 {mu}g{center_dot}L{sup -1} using tube, platform tube and filter furnace atomizers. The use of various atomizers, lines, elements and atomization temperatures made possible the simulation of various practical analytical conditions. It was found that the algorithm and optimal linearization parameters made it possible to obtain for each line and atomizer linear approximations of the calibration curves within 3-4 orders of magnitude with correlation coefficients close to 0.999. The algorithm makes possible to employ a single line for the direct element determination over a broad concentration range. The sources of errors and the possibility of a priori theoretical evaluation of the linearization parameters are discussed. - Highlights: Black-Right-Pointing-Pointer New calculation algorithm for HR-CS ET AAS measurements was proposed and applied. Black-Right-Pointing-Pointer The suggested formulas include two parameters to be determined experimentally. Black

  2. Molecular characterization of water soluble organic nitrogen in marine rainwater by ultra-high resolution electrospray ionization mass spectrometry

    Directory of Open Access Journals (Sweden)

    K. E. Altieri

    2012-04-01

    Full Text Available Atmospheric water soluble organic nitrogen (WSON is a subset of the complex organic matter in aerosols and rainwater, which impacts cloud condensation processes and aerosol chemical and optical properties and may play a significant role in the biogeochemical cycle of N. However, its sources, composition, connections to inorganic N, and variability are largely unknown. Rainwater samples were collected on the island of Bermuda (32.27° N, 64.87° W, which experiences both anthropogenic and marine influenced air masses. Samples were analyzed by ultra-high resolution electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry to chemically characterize the WSON. Elemental compositions of 2281 N containing compounds were determined over the mass range m/z+ 50 to 500. The five compound classes with the largest number of elemental formulas identified, in order from the highest number of formulas to the lowest, contained carbon, hydrogen, oxygen, and nitrogen (CHON+, CHON compounds that contained sulfur (CHONS+, CHON compounds that contained phosphorus (CHONP+, CHON compounds that contained both sulfur and phosphorus (CHONSP+, and compounds that contained only carbon, hydrogen, and nitrogen (CHN+. Compared to rainwater collected in the continental USA, average O:C ratios of all N containing compound classes were lower in the marine samples whereas double bond equivalent values were higher, suggesting a reduced role of secondary formation mechanisms. Despite their prevalence in continental rainwater, no organonitrates or nitrooxy-organosulfates were detected, but there was an increased presence of organic S and organic P containing compounds in the marine rainwater. Cluster analysis showed a clear chemical distinction between samples collected during the cold season (October to March which have anthropogenic air mass origins and samples collected during the warm season (April to September with remote

  3. The coupling of supercritical fluid chromatography and field ionization time-of-flight high-resolution mass spectrometry for rapid and quantitative analysis of petroleum middle distillates.

    Science.gov (United States)

    Qian, Kuangnan; Diehl, John W; Dechert, Gary J; DiSanzo, Frank P

    2004-01-01

    We report the first coupling of supercritical fluid chromatography (SFC) with field ionization time-of-flight high-resolution mass spectrometry (FI-ToF HRMS), in parallel with ultraviolet (UV) detection and flame ionization detection (FID), for rapid and quantitative analysis of petroleum middle distillates. SFC separates petroleum middle distillates into saturates and 1- to 3-ring aromatics. FI generates molecular ions for hydrocarbon species eluted from the SFC. The high resolution and exact mass measurements by ToF mass spectrometry provide elemental compositions of the molecules in the petroleum product. The amounts of saturates and aromatic ring types were quantified using the parallel SFC-FID assisted by SFC-UV. With a proper carbon-number calibration, the detailed composition of the petroleum middle distillate was rapidly determined.

  4. Determination of 241Am in sediments by isotope dilution high resolution inductively coupled plasma mass spectrometry (ID HR ICP-MS).

    Science.gov (United States)

    Agarande, M; Benzoubir, S; Bouisset, P; Calmet, D

    2001-08-01

    Trace levels (pg kg(-1)) of 241Am in sediments were determined by isotope dilution high resolution inductively coupled plasma mass spectrometry (ID HR ICP-MS) using a microconcentric nebulizer. 241Am was isolated from major elements like Ca and Fe by different selective precipitations. In further steps. Am was first separated from other transuranic elements and purified by anion exchange and extraction chromatography prior to the mass spectrometric measurements. The ID HR ICP-MS results are compared with isotope dilution alpha spectrometry.

  5. Position sensitive detection coupled to high-resolution time-of-flight mass spectrometry: Imaging for molecular beam deflection experiments

    International Nuclear Information System (INIS)

    Abd El Rahim, M.; Antoine, R.; Arnaud, L.; Barbaire, M.; Broyer, M.; Clavier, Ch.; Compagnon, I.; Dugourd, Ph.; Maurelli, J.; Rayane, D.

    2004-01-01

    We have developed and tested a high-resolution time-of-flight mass spectrometer coupled to a position sensitive detector for molecular beam deflection experiments. The major achievement of this new spectrometer is to provide a three-dimensional imaging (X and Y positions and time-of-flight) of the ion packet on the detector, with a high acquisition rate and a high resolution on both the mass and the position. The calibration of the experimental setup and its application to molecular beam deflection experiments are discussed

  6. Gamma-ray spectrometry applied to down-hole logging

    International Nuclear Information System (INIS)

    Dumesnil, P.; Umiastowsky, K.

    1983-11-01

    Gamma-ray spectrometry permits to improve the accuracy of natural gamma, gamma-gamma and neutron-gamma geophysical measurements. The probe developed at Centre d'Etudes Nucleaires de Saclay allows down-hole gamma-ray spectrometry. Among others, this probe can be applied to the uranium content determination by selective natural gamma method, down-hole determination of the ash content in the coal by gamma-gamma selective method and elemental analysis by neutron-gamma method. For the calibration and an exact interpretation of the measurements it is important to know the gamma-ray and neutron characteristics of the different kinds of rocks considered as probabilistic variables

  7. 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...

  8. High resolution gamma spectrometry of size-separated soils from high background areas of Kerala

    International Nuclear Information System (INIS)

    Menon, M.R.; Sadasivan, S.; Nambi, K.S.V.

    1992-01-01

    Soil samples from a high background area of Kerala were analysed for their natural radionuclide content and distribution with particle size. The samples exhibited inhomogeneity in activity distribution. The smaller size particles had higher activity. The open air dose estimates are also presented. (author). 5 refs., 2 tabs

  9. Standard guide for high-resolution gamma-ray spectrometry of soil samples. ASTM standard

    International Nuclear Information System (INIS)

    1998-12-01

    This guide is under the jurisdiction of ASTM Committee C-26 on Nuclear Fuel Cycle and is the direct responsibility of Subcommittee C26.05 on Methods of Test. The current edition was approved on Jul. 10, 1998. It was published in December 1998. Copyright American Society for Testing and Materials (ASTM), 100 Barr Harbor Drive, West Conshohocken, PA, 19428, USA. This document is available from NTIS under license from ASTM

  10. Neutron activation analysis of high purity silver using high resolution gamma-spectrometry

    International Nuclear Information System (INIS)

    Gilbert, E.N.; Veriovkin, G.V.; Botchkaryov, B.N.; Godovikov, A.A.; Zhavoronkov, V.Ya.; Mikhailov, V.A.

    1975-01-01

    A method of neutron activation determination of microimpurities in high purity silver has been developed. For matrix activity separation the extraction of silver by dibuthylsulfide /DBS/ was employed. The purification coefficient was 10 8 after triple extraction. To study the behaviour of microimpurities in the extraction procedure and to determine their chemical yields some tracer experiments were undertaken with radionuclides of Na, Se, Fe, Co, Cu, As, Sc, Te, Zr, Hf, Mo, W, Cd, In, Sb, La, Ce, Eu, Ta, Re, Ir, Ru. All the elements studied were found to remain in the aqueous phase up to 96-99% after triple extraction with DBS. To estimate the accuracy of the method and to study the mutual influence of the elements in the sample in various relative amounts on the accuracy of the analysis, a number of experiments of ''added-found'' type was performed and the results were treated statistically. In these experiments model mixtures of 30 nuclides were analysed after triple DBS extraction. The t-criterion values for the confidence interval at P=0.95 show the absence of systematic errors. Variation coefficient values do not exceed 15%. Using Ge/Li/ detector it was possible to determine 30 elements simultaneously in silver samples. (T.G.)

  11. Novel strategy for the determination of illegal adulterants in health foods and herbal medicines using high-performance liquid chromatography with high-resolution mass spectrometry.

    Science.gov (United States)

    Wang, Zhe; Wu, Caisheng; Wang, Gangli; Zhang, Qingsheng; Zhang, Jinlan

    2015-03-01

    The detection, confirmation, and quantification of multiple illegal adulterants in health foods and herbal medicines by using a single analytical method are a challenge. This paper reports on a new strategy to meet this challenge by employing high-performance liquid chromatography coupled with high-resolution mass spectrometry and a mass spectral tree similarity filter technique. This analytical method can rapidly collect high-resolution, high-accuracy, optionally multistage mass data for compounds in samples. After a preliminary screening by retention time and high-resolution mass spectral data, known illegal adulterants can be detected. The mass spectral tree similarity filter technique has been applied to rapidly confirm these adulterants and simultaneously discover unknown ones. By using full-scan mass spectra as stem and data-dependent subsequent stage mass spectra to form branches, mass spectrometry data from detected compounds are converted into mass spectral trees. The known or unknown illegal adulterants in the samples are confirmed or discovered based on the similarity between their mass spectral trees and those of the references in a library, and they are finally quantified against standard curves. This new strategy has been tested by using 50 samples, and the illegal adulterants were rapidly and effectively detected, confirmed and quantified. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Determination of cobalt in biological samples by line-source and high-resolution continuum source graphite furnace atomic absorption spectrometry using solid sampling or alkaline treatment

    International Nuclear Information System (INIS)

    Ribeiro, Anderson Schwingel; Vieira, Mariana Antunes; Furtado da Silva, Alessandra; Borges, Daniel L. Gallindo; Welz, Bernhard; Heitmann, Uwe; Curtius, Adilson Jose

    2005-01-01

    Two procedures for the determination of Co in biological samples by graphite furnace atomic absorption spectrometry (GF AAS) were compared: solid sampling (SS) and alkaline treatment with tetramethylammonium hydroxide (TMAH) using two different instruments for the investigation: a conventional line-source (LS) atomic absorption spectrometer and a prototype high-resolution continuum source atomic absorption spectrometer. For the direct introduction of the solid samples, certified reference materials (CRM) were ground to a particle size ≤50 μm. Alkaline treatment was carried out by placing about 250 mg of the sample in polypropylene flasks, adding 2 mL of 25% m/v tetramethylammonium hydroxide and de-ionized water. Due to its unique capacity of providing a 3-D spectral plot, a high-resolution continuum source (HR-CS) graphite furnace atomic absorption spectrometry was used as a tool to evaluate potential spectral interferences, including background absorption for both sample introduction procedures, revealing that a continuous background preceded the atomic signal for pyrolysis temperatures lower than 700 deg. C. Molecular absorption bands with pronounced rotational fine structure appeared for atomization temperatures >1800 deg. C probably as a consequence of the formation of PO. After optimization had been carried out using high resolution continuum source atomic absorption spectrometry, the optimized conditions were adopted also for line-source atomic absorption spectrometry. Six biological certified reference materials were analyzed, with calibration against aqueous standards, resulting in agreement with the certified values (according to the t-test for a 95% confidence level) and in detection limits as low as 5 ng g -1

  13. High-resolution gamma spectroscopy with whole-body and partial-body counters. Experience, recommendations. Report; Hochaufloesende Gamma-Spektrometrie an Ganz- und Teilkoerperzaehlern. Erfahrungen, Empfehlungen. Bericht

    Energy Technology Data Exchange (ETDEWEB)

    Sahre, P. [comp.

    1997-12-01

    The application of high-resolution gamma spectroscopy with whole-body and partial-body counters shows a steadily rising upward trend over the last few years. This induced the ``Arbeitskreis Inkorporationsueberwachung`` of the association ``Fachverband fuer Strahlenschutz e.V.`` to organise a meeting for joint elaboration of a guide on recommended applications of this measuring technique, based on a review of existing experience and results. A key item on the agenda of the meeting was the comparative evaluation of the Ge semiconductor detector and the NaI solid scintillation detector. (orig./CB) [Deutsch] Der Einsatz der hochaufloesenden Gammaspektroskopie in Ganz- und Teilkoerperzaehlern hat in den letzten Jahren stetig zugenommen. Der ``Arbeitskreis Inkorporationsueberwachung`` des Fachverbandes fuer Strahlenschutz e.V. hat darum bisherige Erfahrungen zusammengetragen und Empfehlungen fuer den Einsatz dieser Messtechnik erarbeitet. Der Schwerpunkt der Tagung lag beim Vergleich von Germaniumhalbleiter- mit Natriumjodid-Festszintillationsdetektoren.Tl-Detektoren eignen sich v.a. beim Vorhandensein bekannter und zeitlich konstanter Nuklidvektoren (Kernkraftwerke, Nuklearmedizin). Bei unbekanntem bzw. variablem Nuklidvektor (Stoerfall, Unfall, Forschung) sollen Ge-Detektoren benutzt werden (orig./ABI)

  14. High Resolution Gamma Ray Spectroscopy at MHz Counting Rates With LaBr3 Scintillators for Fusion Plasma Applications

    Science.gov (United States)

    Nocente, M.; Tardocchi, M.; Olariu, A.; Olariu, S.; Pereira, R. C.; Chugunov, I. N.; Fernandes, A.; Gin, D. B.; Grosso, G.; Kiptily, V. G.; Neto, A.; Shevelev, A. E.; Silva, M.; Sousa, J.; Gorini, G.

    2013-04-01

    High resolution γ-ray spectroscopy measurements at MHz counting rates were carried out at nuclear accelerators, combining a LaBr 3(Ce) detector with dedicated hardware and software solutions based on digitization and off-line analysis. Spectra were measured at counting rates up to 4 MHz, with little or no degradation of the energy resolution, adopting a pile up rejection algorithm. The reported results represent a step forward towards the final goal of high resolution γ-ray spectroscopy measurements on a burning plasma device.

  15. Characterization of Athabasca lean oil sands and mixed surficial materials: Comparison of capillary electrophoresis/low-resolution mass spectrometry and high-resolution mass spectrometry.

    Science.gov (United States)

    MacLennan, Matthew S; Peru, Kerry M; Swyngedouw, Chris; Fleming, Ian; Chen, David D Y; Headley, John V

    2018-05-15

    Oil sands mining in Alberta, Canada, requires removal and stockpiling of considerable volumes of near-surface overburden material. This overburden includes lean oil sands (LOS) which cannot be processed economically but contain sparingly soluble petroleum hydrocarbons and naphthenic acids, which can leach into environmental waters. In order to measure and track the leaching of dissolved constituents and distinguish industrially derived organics from naturally occurring organics in local waters, practical methods were developed for characterizing multiple sources of contaminated water leakage. Capillary electrophoresis/positive-ion electrospray ionization low-resolution time-of-flight mass spectrometry (CE/LRMS), high-resolution negative-ion electrospray ionization Orbitrap mass spectrometry (HRMS) and conventional gas chromatography/flame ionization detection (GC/FID) were used to characterize porewater samples collected from within Athabasca LOS and mixed surficial materials. GC/FID was used to measure total petroleum hydrocarbon and HRMS was used to measure total naphthenic acid fraction components (NAFCs). HRMS and CE/LRMS were used to characterize samples according to source. The amounts of total petroleum hydrocarbon in each sample as measured by GC/FID ranged from 0.1 to 15.1 mg/L while the amounts of NAFCs as measured by HRMS ranged from 5.3 to 82.3 mg/L. Factors analysis (FA) on HRMS data visually demonstrated clustering according to sample source and was correlated to molecular formula. LRMS coupled to capillary electrophoresis separation (CE/LRMS) provides important information on NAFC isomers by adding analyte migration time data to m/z and peak intensity. Differences in measured amounts of total petroleum hydrocarbons by GC/FID and NAFCs by HRMS indicate that the two methods provide complementary information about the nature of dissolved organic species in a soil or water leachate samples. NAFC molecule class O x S y is a possible tracer for LOS

  16. Low level GAMMA0 spectrometry by beta-gamma coincidence

    International Nuclear Information System (INIS)

    Grigorescu, E.L.; Luca, A.; Razdolescu, A.C.; Ivan, C.

    1999-01-01

    Low level gamma spectrometry has a wide application, especially in environmental monitoring. Two variants, based on a beta-gamma coincidence technique, were studied. The equipment was composed of a beta detector and a Ge(Li) gamma detector (6% - relative efficiency), with the associated electronics. The gamma rays are recorded by the multichannel analyzer (4096 channels) only if the associated beta particles, which precede the gamma transitions, are registered in coincidence. Two types of beta detectors were used: plastic and liquid scintillators. In both cases, an external lead shield of 5 cm thick was used. The integral gamma background (50-1700 KeV) was reduced about 85 and 50 times, respectively. The corresponding MDA (Minimum Detectable Activity) values decreased about 1.5 and (3-7) times, respectively. The 2π sr plastic beta detector was placed on top the Ge(Li). The sample was inserted between the two detectors. The measurement time was 10 4 s. A 4π sr detector, built of the same material, was also studied, but it proved to be less advantageous because the background was reduced only 16 times; for a MDA reduction similar with that of the 2π sr variant, a longer measurement was needed (3.10 4 s). The other type of beta detector used, was a liquid scintillator. The dissolving of the samples in scintillator ensures a 4π sr measurement geometry. The vials with scintillator (10 ml volume) were placed on top the Ge(Li) and visualised by the photocathode of a phototube. This setup was surrounded by an enclosure which prevent the light penetration. The measurement time was 10 4 s. The only difficulty encountered in this low level measurement method is the accurate determination of the beta efficiency. A limitation is the possibility to measure only small mass samples. These variants are more simple and cheaper than others, previously studied. The advantage of the method is obvious when, instead of low MDA values, shorter measurement times are preferred. The

  17. Velocity-space observation regions of high-resolution two-step reaction gamma-ray spectroscopy

    DEFF Research Database (Denmark)

    Salewski, Mirko; Nocente, M.; Gorini, G.

    2015-01-01

    High-resolution γ-ray spectroscopy (GRS) measurements resolve spectral shapes of Dopplerbroadened γ-rays. We calculate weight functions describing velocity-space sensitivities of any two-step reaction GRS measurements in magnetized plasmas using the resonant nuclear reaction 9Be(α, nγ)12C...

  18. Programmer for automatic gamma spectrometry; Ordonnateur de sequence pour spectrometrie gamma automatique

    Energy Technology Data Exchange (ETDEWEB)

    Romanetti, R [Commissariat a l' Energie Atomique, Cadarache (France). Centre d' Etudes Nucleaires

    1968-04-01

    With this apparatus, which is constructed of logical integrated circuits, it is possible both to synchronize an automatic gamma spectrometry assembly and to record the spectra on punched cards. An IBM terminal will make it possible with the help of analysis by the least squares method and by a direct dialogue with an IBM 360 computer to obtain analytical results almost instantaneously. (author) [French] Cet appareil, realise en circuits integres logiques, permet d'une part de synchroniser un ensemble automatique de spectrometrie gamma et d'autre part d'enregistrer les spectres sur cartes perforees. Un terminal IBM permettra, a l'aide d'un programme d'analyse par la methode des moindres carres et par un dialogue direct avec un ordinateur IBM 360, de disposer presque intanstanement des resultats des analyses. (auteur)

  19. New possibilities in prompt gamma ray spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Borderie, B; Barrandon, J N [Centre National de la Recherche Scientifique, 45 - Orleans-la-Source (France). Lab. du cyclotron; Pinault, J L [Bureau de Recherches Geologiques et Minieres (BRGM), 45 - Orleans (France)

    1977-01-01

    Prompt gamma ray spectrometry has been used as an analytical tool for many years. The high level of background noise does, however, remain a major problem with this technique. From simple theoretical consideration, conditions (particle, energy) were determined to reduce significantly the background noise under irradiation. Alpha particles of 3.5 MeV were chosen. Some fifty elements were studied, of which 24 gave interesting results. The detection limits obtained for a sample of niobium were as follows: approximately 1 ppm (10/sup -6/g/g) for the light elements Li, B, F and Na, and between 50 ppm and 1% for the others. Numerous applications may be envisaged in the geo- and cosmo-sciences.

  20. Composite mapping experiences in airborne gamma spectrometry

    International Nuclear Information System (INIS)

    Bucher, B.

    2014-01-01

    During an international intercomparison exercise of airborne gamma spectrometry held in Switzerland 2007 teams from Germany, France and Switzerland were proving their capabilities. One of the tasks was the composite mapping of an area around Basel. Each team was mainly covering the part of its own country at its own flying procedures. They delivered the evaluated data in a data format agreed in advance. The quantities to be delivered were also defined in advance. Nevertheless, during the process to put the data together a few questions raised: Which dose rate was meant? Had the dose rate to be delivered with or without cosmic contribution? Activity per dry or wet mass? Which coordinate system was used? Finally, the data could be put together in one map. For working procedures in case of an emergency, quantities of interest and exchange data format have to be defined in advance. But the procedures have also to be proved regularly. (author)

  1. In situ gamma spectrometry development for site mapping

    International Nuclear Information System (INIS)

    Panza, F.

    2012-01-01

    The high-resolution gamma spectrometry currently provides a powerful analytical tool for performing environmental measurements. In the context of radiological characterization of a site (natural or artificial radioactivity) and for the dismantling of nuclear installations, mapping of radionuclides is an important asset. The idea is to move a HPGe spectrometer to study the site and from nuclear and position data, to identify, to locate and to quantify the radionuclides present in the soil. The development of this tool follows an intercomparison (ISIS 2007) where an intervention/crisis exercise showed the limits of current tools. The main part of this research project has focused on mapping of nuclear data. Knowledge of the parameters of an in situ spectrum helped to create a simulator, modeling the response of a spectrometer moving over contaminated soil. The simulator itself helped to develop algorithms for mapping and to test them in extreme situations and not realizable. A large part of this research leads to the creation of a viable prototype providing real-time information concerning the identity and locality as possible radionuclides. The work performed on the deconvolution of data can make in post processing a map of the activity of radionuclide soil but also an indication of the depth distribution of the source. The prototype named OSCAR was tested on contaminated sites (Switzerland and Japan) and the results are in agreement with reference measurements. (author)

  2. Determination of sulfur in bovine serum albumin and L-cysteine using high-resolution continuum source molecular absorption spectrometry of the CS molecule

    Science.gov (United States)

    Andrade-Carpente, Eva; Peña-Vázquez, Elena; Bermejo-Barrera, Pilar

    2016-08-01

    In this study, the content of sulfur in bovine serum albumin and L-cysteine was determined using high-resolution continuum source molecular absorption spectrometry of the CS molecule, generated in a reducing air-acetylene flame. Flame conditions (height above the burner, measurement time) were optimized using a 3.0% (v/v) sulfuric acid solution. A microwave lab station (Ethos Plus MW) was used for the digestion of both compounds. During the digestion step, sulfur was converted to sulfate previous to the determination. Good repeatability (4-10%) and analytical recovery (91-106%) was obtained.

  3. Prediction of collision cross section and retention time for broad scope screening in gradient reversed-phase liquid chromatography-ion mobility-high resolution accurate mass spectrometry

    DEFF Research Database (Denmark)

    Mollerup, Christian Brinch; Mardal, Marie; Dalsgaard, Petur Weihe

    2018-01-01

    artificial neural networks (ANNs). Prediction was based on molecular descriptors, 827 RTs, and 357 CCS values from pharmaceuticals, drugs of abuse, and their metabolites. ANN models for the prediction of RT or CCS separately were examined, and the potential to predict both from a single model......Exact mass, retention time (RT), and collision cross section (CCS) are used as identification parameters in liquid chromatography coupled to ion mobility high resolution accurate mass spectrometry (LC-IM-HRMS). Targeted screening analyses are now more flexible and can be expanded for suspect...

  4. Fission-product yields for thermal-neutron fission of 243Cm determined from measurements with a high-resolution low-energy germanium gamma-ray detector

    International Nuclear Information System (INIS)

    Merriman, L.D.

    1984-04-01

    Cumulative fission-product yields have been determined for 13 gamma rays emitted during the decay of 12 fission products created by thermal-neutron fission of 243 Cm. A high-resolution low-energy germanium detector was used to measure the pulse-height spectra of gamma rays emitted from a 77-nanogram sample of 243 Cm after the sample had been irradiated by thermal neutrons. Analysis of the data resulted in the identification and matching of gamma-ray energies and half-lives to individual radioisotopes. From these results, 12 cumulative fission product yields were deduced for radionuclides with half-lives between 4.2 min and 84.2 min. 7 references

  5. Development of isotope dilution gamma-ray spectrometry for plutonium analysis

    Energy Technology Data Exchange (ETDEWEB)

    Li, T.K.; Parker, J.L. (Los Alamos National Lab., NM (United States)); Kuno, Y.; Sato, S.; Kurosawa, A.; Akiyama, T. (Power Reactor and Nuclear Fuel Development Corp., Tokai, Ibaraki (Japan))

    1991-01-01

    We are studying the feasibility of determining the plutonium concentration and isotopic distribution of highly radioactive, spent-fuel dissolver solutions by employing high-resolution gamma-ray spectrometry. The study involves gamma-ray plutonium isotopic analysis for both dissolver and spiked dissolver solution samples, after plutonium is eluted through an ion-exchange column and absorbed in a small resin bead bag. The spike is well characterized, dry plutonium containing {approximately}98% of {sup 239}Pu. By using measured isotopic information, the concentration of elemental plutonium in the dissolver solution can be determined. Both the plutonium concentration and the isotopic composition of the dissolver solution obtained from this study agree well with values obtained by traditional isotope dilution mass spectrometry (IDMS). Because it is rapid, easy to operate and maintain, and costs less, this new technique could be an alternative method to IDMS for input accountability and verification measurements in reprocessing plants. 7 refs., 4 figs., 4 tabs.

  6. A four dimensional separation method based on continuous heart-cutting gas chromatography with ion mobility and high resolution mass spectrometry.

    Science.gov (United States)

    Lipok, Christian; Hippler, Jörg; Schmitz, Oliver J

    2018-02-09

    A two-dimensional GC (2D-GC) method was developed and coupled to an ion mobility-high resolution mass spectrometer, which enables the separation of complex samples in four dimensions (2D-GC, ion mobilility spectrometry and mass spectrometry). This approach works as a continuous multiheart-cutting GC-system (GC+GC), using a long modulation time of 20s, which allows the complete transfer of most of the first dimension peaks to the second dimension column without fractionation, in comparison to comprehensive two-dimensional gas chromatography (GCxGC). Hence, each compound delivers only one peak in the second dimension, which simplifies the data handling even when ion mobility spectrometry as a third and mass spectrometry as a fourth dimension are introduced. The analysis of a plant extract from Calendula officinales shows the separation power of this four dimensional separation method. The introduction of ion mobility spectrometry provides an additional separation dimension and allows to determine collision cross sections (CCS) of the analytes as a further physicochemical constant supporting the identification. A CCS database with more than 800 standard substances including drug-like compounds and pesticides was used for CCS data base search in this work. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Accurate and precise 40Ar/39Ar dating by high-resolution, multi-collection, mass spectrometry

    DEFF Research Database (Denmark)

    Storey, Michael; Rivera, Tiffany; Flude, Stephanie

    New generation, high resolution, multi-collector noble gas mass spectrometers equipped with ion-counting electron multipliers provide opportunities for improved accuracy and precision in 40Ar/39Ar dating. Here we report analytical protocols and age cross-calibration studies using a NU-Instruments......New generation, high resolution, multi-collector noble gas mass spectrometers equipped with ion-counting electron multipliers provide opportunities for improved accuracy and precision in 40Ar/39Ar dating. Here we report analytical protocols and age cross-calibration studies using a NU......-Instruments multi-collector Noblesse noble gas mass spectrometer configured with a faraday detector and three ion-counting electron multipliers. The instrument has the capability to measure several noble gas isotopes simultaneously and to change measurement configurations instantaneously by the use of QUAD lenses...... (zoom optics). The Noblesse offer several advantages over previous generation noble gas mass spectrometers and is particularly suited for single crystal 40Ar/39Ar dating because of: (i) improved source sensitivity (ii) ion-counting electron multipliers, which have much lower signal to noise ratios than...

  8. Characterization of Chemical Composition of Pericarpium Citri Reticulatae Volatile Oil by Comprehensive Two-Dimensional Gas Chromatography with High-Resolution Time-of-Flight Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Kunming Qin

    2013-01-01

    Full Text Available Pericarpium Citri Reticulatae (Chenpi in Chinese has been widely used as an herbal medicine in Korea, China, and Japan. Chenpi extracts are used to treat indigestion and inflammatory syndromes of the respiratory tract such as bronchitis and asthma. This thesis will analyze chemical compositions of Chenpi volatile oil, which was performed by comprehensive two-dimensional gas chromatography with high-resolution time-of-flight mass spectrometry (GC × GC-HR-TOFMS. One hundred and sixty-seven components were tentatively identified, and terpene compounds are the main components of Chenpi volatile oil, a significant larger number than in previous studies. The majority of the eluted compounds, which were identified, were well separated as a result of high-resolution capability of the GC × GC method, which significantly reduces, the coelution. β-Elemene is tentatively qualified by means of GC × GC in tandem with high-resolution TOFMS detection, which plays an important role in enhancing the effects of many anticancer drugs and in reducing the side effects of chemotherapy. This study suggests that GC × GC-HR-TOFMS is suitable for routine characterization of chemical composition of volatile oil in herbal medicines.

  9. Review: LC coupled to low- and high-resolution mass spectrometry for new psychoactive substance screening in biological matrices - Where do we stand today?

    Science.gov (United States)

    Meyer, Markus R; Maurer, Hans H

    2016-07-13

    The field of new psychoactive substances (NPS) is highly dynamic and the situation changes from year to year. Therefore, the current review provides a timely update about the latest developments to help analysts keep the pace with NPS distribution. It covers PubMed-listed studies published between January 2014 and January 2016 dealing with the application of liquid chromatography (LC) coupled low- and high-resolution mass spectrometry (MS) for broad screenings for NPS in clinical (CT) and forensic (FT) toxicology. Latest developments and applications are highlighted and selected papers critically discussed. Comprehensive tables summarizing all discussed articles complete the overview. Finally, an outlook on the future of LC coupled MS in CT and FT is provided and readers will learn why low-resolution mass spectrometry might remain the standard for the next couple of years at least for easy-to-use quantitative screening procedures. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Determination of gold and cobalt dopants in advanced materials based on tin oxide by slurry sampling high-resolution continuum source graphite furnace atomic absorption spectrometry

    Science.gov (United States)

    Filatova, Daria G.; Eskina, Vasilina V.; Baranovskaya, Vasilisa B.; Vladimirova, Svetlana A.; Gaskov, Alexander M.; Rumyantseva, Marina N.; Karpov, Yuri A.

    2018-02-01

    A novel approach is developed for the determination of Co and Au dopants in advanced materials based on tin oxide using high-resolution continuum source graphite furnace atomic absorption spectrometry (HR CS GFAAS) with direct slurry sampling. Sodium carboxylmethylcellulose (Na-CMC) is an effective stabilizer for diluted suspensions. Use Na-CMC allows to transfer the analytes into graphite furnace completely and reproducibly. The relative standard deviation obtained by HR CS GFAAS was not higher than 4%. Accuracy was proven by means inductively coupled plasma mass spectrometry (ICP-MS) in solutions after decomposition as a comparative technique. To determine Au and Co in the volume of SnO2, the acid decomposition conditions (HCl, HF) of the samples were suggested by means of an autoclave in a microwave oven.

  11. Gamma spectrometry for chronology of recent sediments

    International Nuclear Information System (INIS)

    Pittauerova, Daniela

    2013-01-01

    This thesis deals with several aspects of gamma spectrometric analysis of natural and artificial isotopes in sediments and their use as tracers for qualification and quantification of accumulation and mixing processes in different aquatic environments. Sediment cores from three distinct areas including terrigenous sediments deposited on the continental slope off NW Africa, deep sea sediments off Sumba Island and five stations from the Gulf of Eilat in the Red Sea area were measured and interpreted within this dissertation. The main concern in gamma spectrometry of voluminous environmental samples is a reliable efficiency calibration. This is specially relevant for the analysis of low energy gamma emitters (<100 keV). 210 Pb, an important isotopic tracer to cover the period of the last century, is one of them. Within this work mathematical efficiency calibration was applied using a commercial software package. A series of validation tests was performed and evaluated for point and voluminous samples. When using 210 Pb as a tracer it is necessary to determine its excess portion, which is not supported by ingrowth from the parent nuclide 226 Ra. Its analysis is mostly performed via short lived daughter isotopes that follow after the intermediate gaseous member 222 Rn. Preventing the escape of radon from the sample is a critical step before analysis due to a negative effect of supported 210 Pb underestimation on the chronology, which was also documented in this thesis. Time series registering ingrowth of 214 Pb and 214 Bi towards radioactive equilibrium with 226 Ra in different containers were evaluated for analyses of 226 Ra. Direct analyses of 226 Ra was compared to its detection via daughter products. A method for aligning parallel radionuclide depth profiles was described and applied successfully in two case studies from the continental slope off NW Africa and off Sumba Island, Indonesia. This is primarily important when combined profiles obtained from short

  12. Gamma spectrometry for chronology of recent sediments

    Energy Technology Data Exchange (ETDEWEB)

    Pittauerova, Daniela

    2013-12-17

    This thesis deals with several aspects of gamma spectrometric analysis of natural and artificial isotopes in sediments and their use as tracers for qualification and quantification of accumulation and mixing processes in different aquatic environments. Sediment cores from three distinct areas including terrigenous sediments deposited on the continental slope off NW Africa, deep sea sediments off Sumba Island and five stations from the Gulf of Eilat in the Red Sea area were measured and interpreted within this dissertation. The main concern in gamma spectrometry of voluminous environmental samples is a reliable efficiency calibration. This is specially relevant for the analysis of low energy gamma emitters (<100 keV). {sup 210}Pb, an important isotopic tracer to cover the period of the last century, is one of them. Within this work mathematical efficiency calibration was applied using a commercial software package. A series of validation tests was performed and evaluated for point and voluminous samples. When using {sup 210}Pb as a tracer it is necessary to determine its excess portion, which is not supported by ingrowth from the parent nuclide {sup 226}Ra. Its analysis is mostly performed via short lived daughter isotopes that follow after the intermediate gaseous member {sup 222}Rn. Preventing the escape of radon from the sample is a critical step before analysis due to a negative effect of supported {sup 210}Pb underestimation on the chronology, which was also documented in this thesis. Time series registering ingrowth of {sup 214}Pb and {sup 214}Bi towards radioactive equilibrium with {sup 226}Ra in different containers were evaluated for analyses of {sup 226}Ra. Direct analyses of {sup 226}Ra was compared to its detection via daughter products. A method for aligning parallel radionuclide depth profiles was described and applied successfully in two case studies from the continental slope off NW Africa and off Sumba Island, Indonesia. This is primarily important

  13. Evaluation of a high-resolution, breast-specific, small-field-of-view gamma camera for the detection of breast cancer

    International Nuclear Information System (INIS)

    Brem, R.F.; Kieper, D.A.; Rapelyea, J.A.; Majewski, S.

    2003-01-01

    Purpose: The purpose of our study is to review the state of the art in nuclear medicine imaging of the breast (scintimammography) and to evaluate a novel, high-resolution, breast-specific gamma camera (HRBGC) for the detection of suspicious breast lesions. Materials and Methods: Fifty patients with 58 breast lesions in whom a scintimammogram was clinically indicated were prospectively evaluated with a general-purpose gamma camera and a HRBGC prototype. Nuclear studies were prospectively classified as negative (normal/benign) or positive (suspicious/malignant) by two radiologists, blinded to mammographic and histologic results with both the conventional and high-resolution. All lesions were confirmed by pathology. Results: Included in this study were 30 benign and 28 malignant lesions. The sensitivity for detection of breast cancer was 64.3% (18/28) with the conventional camera and 78.6% (22/28) with the HRBGC. Specificity of both systems was 93.3% (28/30). In the 18 nonpalpable cancers, sensitivity was 55.5% (10/18) and 72.2% (13/18) with the general-purpose camera and HRBGC, respectively. In cancers ≤ 1cm, 7 of 15 were detected with the general-purpose camera and 10 of 15 with the HRBGC. Four of the cancers (median size, 8.5 mm) detected with the HRBGC were missed by the conventional camera Conclusion: Evaluation of indeterminate breasts lesions with a high resolution, breast-specific gamma camera results in improved sensitivity for the detection of cancer with greater improvement demonstrated in nonpalpable and ≤1 cm cancers

  14. Natural radioactivity in iron and steel materials by low-level gamma spectrometry

    International Nuclear Information System (INIS)

    Tanase, G.; Tanase, Maria

    2003-01-01

    High resolution low-level gamma spectrometry was applied to perform a radioactivity measurement in iron and steel raw materials (coal, coke, iron ore, pellets, manganese ore, limestone, dolomite), auxiliary materials (scorialite, oxide of Ti, bentonite), and some related final products (cast iron, slag, blast-furnace, flue dust) involved in iron making processing. We control the activity of materials in various kinds of samples and we investigate for transfer of radioactivity during the blast-furnace process. Artificial radioisotopes are rarely encountered. (authors)

  15. Characterization of Uranium-Bearing Material by Passive Non-Destructive Gamma Spectrometry

    International Nuclear Information System (INIS)

    Lakosi, L.; Zsigrai, J.; Nguyen, C.T.

    2009-01-01

    Characterization of nuclear materials is equally important in nuclear safeguards (inventory verification) and in nuclear security (revealing illicit trafficking). Analysis of materials is a key issue in both fields. Natural (NU), depleted (DU), low-enriched (LEU), and high-enriched uranium (HEU) samples were analysed by high resolution gamma spectrometry (HRGS). Isotopic composition and total U-content of reactor fuel pellets and powder were determined. A unique HRGS method was developed for the first time for determining the production date of the material of unknown origin. Identifying reprocessed uranium proved to be possible by HRGS as well.

  16. 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

  17. Use of ultra-high pressure liquid chromatography coupled to high resolution mass spectrometry for fast screening in high throughput doping control.

    Science.gov (United States)

    Musenga, Alessandro; Cowan, David A

    2013-05-03

    We describe a sensitive, comprehensive and fast screening method based on liquid chromatography-high resolution mass spectrometry for the detection of a large number of analytes in sports samples. UHPLC coupled to high resolution mass spectrometry with polarity switching capability is applied for the rapid screening of a large number of analytes in human urine samples. Full scan data are acquired alternating both positive and negative ionisation. Collision-induced dissociation with positive ionisation is also performed to produce fragment ions to improve selectivity for some analytes. Data are reviewed as extracted ion chromatograms based on narrow mass/charge windows (±5ppm). A simple sample preparation method was developed, using direct enzymatic hydrolysis of glucuronide conjugates, followed by solid phase extraction with mixed mode ion-exchange cartridges. Within a 10min run time (including re-equilibration) the method presented allows for the analysis of a large number of analytes from most of the classes in the World Anti-Doping Agency (WADA) Prohibited List, including anabolic agents, β2-agonists, hormone antagonists and modulators, diuretics, stimulants, narcotics, glucocorticoids and β-blockers, and does so while meeting the WADA sensitivity requirements. The high throughput of the method and the fast sample pre-treatment reduces analysis cost and increases productivity. The method presented has been used for the analysis of over 5000 samples in about one month and proved to be reliable. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Investigating effects of sample pretreatment on protein stability using size-exclusion chromatography and high-resolution continuum source atomic absorption spectrometry.

    Science.gov (United States)

    Rakow, Tobias; El Deeb, Sami; Hahne, Thomas; El-Hady, Deia Abd; AlBishri, Hassan M; Wätzig, Hermann

    2014-09-01

    In this study, size-exclusion chromatography and high-resolution atomic absorption spectrometry methods have been developed and evaluated to test the stability of proteins during sample pretreatment. This especially includes different storage conditions but also adsorption before or even during the chromatographic process. For the development of the size exclusion method, a Biosep S3000 5 μm column was used for investigating a series of representative model proteins, namely bovine serum albumin, ovalbumin, monoclonal immunoglobulin G antibody, and myoglobin. Ambient temperature storage was found to be harmful to all model proteins, whereas short-term storage up to 14 days could be done in an ordinary refrigerator. Freezing the protein solutions was always complicated and had to be evaluated for each protein in the corresponding solvent. To keep the proteins in their native state a gentle freezing temperature should be chosen, hence liquid nitrogen should be avoided. Furthermore, a high-resolution continuum source atomic absorption spectrometry method was developed to observe the adsorption of proteins on container material and chromatographic columns. Adsorption to any container led to a sample loss and lowered the recovery rates. During the pretreatment and high-performance size-exclusion chromatography, adsorption caused sample losses of up to 33%. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Elucidation and identification of amino acid containing membrane lipids using liquid chromatography/high-resolution mass spectrometry

    NARCIS (Netherlands)

    Moore, E.K.; Hopmans, E.C.; Rijpstra, W.I.C.; Villanueva, L.; Sinninghe Damsté, J.S.

    2016-01-01

    RATIONALE: Intact polar lipids (IPLs) are the building blocks of cell membranes, and amino acid containing IPLs havebeen observed to be involved in response to changing environmental conditions in various species of bacteri a. High-performance liquid chromatography/mass spectrometry (HPLC/MS) has

  20. Desorption atmospheric pressure photoionization high-resolution mass spectrometry: a complementary approach for the chemical analysis of atmospheric aerosols

    Czech Academy of Sciences Publication Activity Database

    Parshintsev, J.; Vaikkinen, A.; Lipponen, K.; Vrkoslav, Vladimír; Cvačka, Josef; Kostiainen, R.; Kotiaho, T.; Hartonen, K.; Riekkola, M. L.; Kauppila, T. J.

    2015-01-01

    Roč. 29, č. 13 (2015), s. 1233-1241 ISSN 0951-4198 Grant - others:GA AV ČR(CZ) M200551204 Institutional support: RVO:61388963 Keywords : atmospheric aerosols * mass spectrometry * ambient ionization Subject RIV: CB - Analytical Chemistry , Separation Impact factor: 2.226, year: 2015

  1. Inter-pulse high-resolution gamma-ray spectra using a 14 MeV pulsed neutron generator

    Science.gov (United States)

    Evans, L.G.; Trombka, J.I.; Jensen, D.H.; Stephenson, W.A.; Hoover, R.A.; Mikesell, J.L.; Tanner, A.B.; Senftle, F.E.

    1984-01-01

    A neutron generator pulsed at 100 s-1 was suspended in an artificial borehole containing a 7.7 metric ton mixture of sand, aragonite, magnetite, sulfur, and salt. Two Ge(HP) gamma-ray detectors were used: one in a borehole sonde, and one at the outside wall of the sample tank opposite the neutron generator target. Gamma-ray spectra were collected by the outside detector during each of 10 discrete time windows during the 10 ms period following the onset of gamma-ray build-up after each neutron burst. The sample was measured first when dry and then when saturated with water. In the dry sample, gamma rays due to inelastic neutron scattering, neutron capture, and decay were counted during the first (150 ??s) time window. Subsequently only capture and decay gamma rays were observed. In the wet sample, only neutron capture and decay gamma rays were observed. Neutron capture gamma rays dominated the spectrum during the period from 150 to 400 ??s after the neutron burst in both samples, but decreased with time much more rapidly in the wet sample. A signal-to-noise-ratio (S/N) analysis indicates that optimum conditions for neutron capture analysis occurred in the 350-800 ??s window. A poor S/N in the first 100-150 ??s is due to a large background continuum during the first time interval. Time gating can be used to enhance gamma-ray spectra, depending on the nuclides in the target material and the reactions needed to produce them, and should improve the sensitivity of in situ well logging. ?? 1984.

  2. High-resolution mini gamma camera for diagnosis and radio-guided surgery in diabetic foot infection

    International Nuclear Information System (INIS)

    Scopinaro, F.; Capriotti, G.; Di Santo, G.; Capotondi, C.; Micarelli, A.; Massari, R.; Trotta, C.; Soluri, A.

    2006-01-01

    The diagnosis of diabetic foot osteomyelitis is often difficult. 99m Tc-WBC (White Blood Cell) scintigraphy plays a key role in the diagnosis of bone infections. Spatial resolution of Anger camera is not always able to differentiate soft tissue from bone infection. Aim of present study is to verify if HRD (High-Resolution Detector) is able to improve diagnosis and to help surgery. Patients were studied by HRD showing 25.7x25.7 mm 2 FOV, 2 mm spatial resolution and 18% energy resolution. The patients were underwent to surgery and, when necessary, bone biopsy, both guided by HRD. Four patients were positive at Anger camera without specific signs of osteomyelitis. HRS (High-Resolution Scintigraphy) showed hot spots in the same patients. In two of them the hot spot was bar-shaped and it was localized in correspondence of the small phalanx. The presence of bone infection was confirmed at surgery, which was successfully guided by HRS. 99m Tc-WBC HRS was able to diagnose pedal infection and to guide the surgery of diabetic foot, opening a new way in the treatment of infected diabetic foot

  3. High-resolution mini gamma camera for diagnosis and radio-guided surgery in diabetic foot infection

    Energy Technology Data Exchange (ETDEWEB)

    Scopinaro, F. [Department of Radiological Sciences, University ' La Sapienza' Rome (Italy); Capriotti, G. [Department of Radiological Sciences, University ' La Sapienza' Rome (Italy); Di Santo, G. [Department of Radiological Sciences, University ' La Sapienza' Rome (Italy); Capotondi, C. [Unit of Radiology, S. Andrea Hospital, Rome (Italy); Micarelli, A. [Nuclear Medicine, Sulmona Hospital, Sulmona (AQ) (Italy); Massari, R. [Institute of Biomedical Engineering, ISIB-CNR, Rome-Li-tech srl, Lauzacco Pavia di Udine (UD) (Italy); Trotta, C. [Institute of Biomedical Engineering, ISIB-CNR, Rome-Li-tech srl, Lauzacco Pavia di Udine (UD) (Italy); Soluri, A. [Institute of Biomedical Engineering, ISIB-CNR, Rome-Li-tech srl, Lauzacco Pavia di Udine (UD) (Italy)]. E-mail: soluri@isib.cnr.it

    2006-12-20

    The diagnosis of diabetic foot osteomyelitis is often difficult. {sup 99m}Tc-WBC (White Blood Cell) scintigraphy plays a key role in the diagnosis of bone infections. Spatial resolution of Anger camera is not always able to differentiate soft tissue from bone infection. Aim of present study is to verify if HRD (High-Resolution Detector) is able to improve diagnosis and to help surgery. Patients were studied by HRD showing 25.7x25.7 mm{sup 2} FOV, 2 mm spatial resolution and 18% energy resolution. The patients were underwent to surgery and, when necessary, bone biopsy, both guided by HRD. Four patients were positive at Anger camera without specific signs of osteomyelitis. HRS (High-Resolution Scintigraphy) showed hot spots in the same patients. In two of them the hot spot was bar-shaped and it was localized in correspondence of the small phalanx. The presence of bone infection was confirmed at surgery, which was successfully guided by HRS. {sup 99m}Tc-WBC HRS was able to diagnose pedal infection and to guide the surgery of diabetic foot, opening a new way in the treatment of infected diabetic foot.

  4. Triple aldose reductase/α-glucosidase/radical scavenging high-resolution profiling combined with high-performance liquid chromatography – high-resolution mass spectrometry – solid-phase extraction – nuclear magnetic resonance spectroscopy for identification of antidiabetic constituents in crude, extract of Radix Scutellariae

    DEFF Research Database (Denmark)

    Tahtah, Yousof; Kongstad, Kenneth Thermann; Wubshet, Sileshi Gizachew

    2015-01-01

    high-performance liquid chromatography – high-resolution mass spectrometry – solid-phase extraction – nuclear magnetic resonance spectroscopy. The only α-glucosidase inhibitor was baicalein, whereas main aldose reductase inhibitors in the crude extract were baicalein and skullcapflavone II, and main....../α-glucosidase/radical scavenging high-resolution inhibition profile - allowing proof of concept with Radix Scutellariae crude extract as a polypharmacological herbal drug. The triple bioactivity high-resolution profiles were used to pinpoint bioactive compounds, and subsequent structure elucidation was performed with hyphenated...

  5. Multicomponent mixed dopant optimization for rapid screening of polycyclic aromatic hydrocarbons using ultra high performance liquid chromatography coupled to atmospheric pressure photoionization high-resolution mass spectrometry

    KAUST Repository

    Sioud, Salim

    2012-05-04

    RATIONALE To enhance the ionization efficiencies in atmospheric pressure photoionization mass spectrometry a dopant with favorable ionization energy such as chlorobenzene is typically used. These dopants are typically toxic and difficult to mix with water-soluble organic solvents. In order to achieve a more efficient and less toxic dopant, a multicomponent mixed dopant was explored. METHODS A multicomponent mixed dopant for non-targeted rapid screening of polycyclic aromatic hydrocarbons (PAHs) was developed and optimized using ultra high performance liquid chromatography (UPLC) coupled to atmospheric pressure photoionization high-resolution mass spectrometry. Various single and multicomponent mixed dopants consisting of ethanol, chlorobenzene, bromobenzene, anisole and toluene were evaluated. RESULTS Fourteen out of eighteen PAHs were successfully separated and detected at low pg/μL levels within 5 min with high mass accuracy ≤4 ppm. The optimal mixed multicomponent dopant consisted of ethanol/chlorobenzene/bromobenzene/anisole (98.975:0.1:0.9:0.025, v/v %) and it improved the limit of detection (LOD) by 2- to 10-fold for the tested PAHs compared to those obtained with pure chlorobenzene. CONCLUSIONS A novel multicomponent dopant that contains 99% ethanol and 1% mixture of chlorobenzene, bromobenzene and anisole was found to be an effective dopant mixture to ionize PAHs. The developed UPLC multicomponent dopant assisted atmospheric pressure photoionization high-resolution mass spectrometry offered a rapid non targeted screening method for detecting the PAHs at low pg/;μL levels within a 5 min run time with high mass accuracy a;circ4 ppm. Copyright © 2012 John Wiley & Sons, Ltd.

  6. Gamma ray spectrometry: applications in uranium prospecting and environment

    International Nuclear Information System (INIS)

    Lopez, Luis E.

    1999-01-01

    The experience in the use of gamma spectrometry for uranium prospecting and for the determination of natural radiation background is described. The basic principles of the techniques are also given. (author)

  7. Determination of 230Th/232Th and correct methods by High Resolution Inductively Coupled Plasma Mass Spectrometry

    International Nuclear Information System (INIS)

    Xie Shengkai; Guo Dongfa; Tan Jing; Zhang Yanhui; Huang Qiuhong; Gao Aiguo

    2013-01-01

    It is very important for the rapid and reliable determination of 230 Th/ 232 Th in the thorium-230 dating. A method of measuring 230 Th/ 232 Th in natural samples by high resolution inductively coupled plasma mass spectrometer (HR-ICP-MS) was developed on the base of our former work. The precise and accurate of natural 230 Th in geology samples is challenging, as the peak tailing to the high intensity of neighboring peak at 232 Th and the mass discrimination of the instrument. The peak tailing of 238 U to 236 U was used to decrease the peak tailing effect of 232 Th to 230 Th. The mass discrimination factor K between ture and measured isotope ratio was calculated after measuring different 230 Th/ 232 Th ratio solutions. Lab used standard samples was digested in mixed acids of HN0 3 -HF-HCI-HCl0 4 , and separated by the Bio-rad AG 1 × 8 Cl - resin. The measurement method of blank-standard-blank-sample procession was used to determinate the 230 Th/ 232 Th. The measured result of 230 Th/ 232 Th was at (7.29 ± 0.34) × 10 -6 , which agreed with the reference value of (7.33 ± 0.17) × 10 -6 . (authors)

  8. Composite mapping experiences in airborne gamma spectrometry.

    Science.gov (United States)

    Bucher, B

    2014-08-01

    During an international intercomparison exercise of airborne gamma spectrometry held in Switzerland 2007 teams from Germany, France and Switzerland were proving their capabilities. One of the tasks was the composite mapping of an area around Basel. Each team was mainly covering the part of its own country at its own flying procedures. They delivered the evaluated data in a data format agreed in advance. The quantities to be delivered were also defined in advance. Nevertheless, during the process to put the data together a few questions raised: Which dose rate was meant? Had the dose rate to be delivered with or without cosmic contribution? Activity per dry or wet mass? Which coordinate system was used? Finally, the data could be put together in one map. For working procedures in case of an emergency, quantities of interest and exchange data format have to be defined in advance. But the procedures have also to be proved regularly. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  9. Imaging of radiocesium uptake dynamics in a plant body using a newly developed high-resolution gamma camera for radiocesium

    Energy Technology Data Exchange (ETDEWEB)

    Kawachi, Naoki; Yin, Yong-Gen; Suzui, Nobuo; Ishii, Satomi; Fujimaki, Shu [Radiotracer Imaging Gr., Quantum Beam Science Directorate, Japan Atomic Energy Agency (JAEA), 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan); Yoshihara, Toshihiro [Plant Molecular Biology, Laboratory of Environmental Science, Central Research Institute of Electric Power Industry (CRIEPI), 1646 Abiko, Chiba 270-1194 (Japan); Watabe, Hiroshi [Cyclotron and Radioisotope Center (CYRIC), Tohoku University, 6-3Aoba, Aramaki, Aoba-ku, Sendai, Miyagi, 980-8578 (Japan); Yamamoto, Seiichi [Department of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, 1-1-20 Daiko-Minami, Higashi-ku, Nagoya 461-8673 (Japan)

    2014-07-01

    Vast agricultural and forest areas around the Tokyo Electric Power Company Fukushima Daiichi Nuclear Power Station in Japan were contaminated with radiocesium (Cs-134 and Cs-137) after the accident following the earthquake and tsunami in March 2011. A variety of agricultural studies, such as fertilizer management and plant breeding, have been undertaken intensively for reduction of radiocesium uptake in crops, or, enhancement of uptake in phyto-remediation. In this study, we newly developed a gamma camera specific for plant nutritional research, and performed quantitative analyses on uptake and partitioning of radiocesium in intact plant bodies. In general, gamma camera is a common technology in medical imaging, but it is not applicable to high-energy gamma rays such as emissions from Cs-137 (662 keV). Therefore, we designed our new gamma camera to prevent the penetration and scattering of the high-energy gamma rays. A single-crystal scintillator, Ce-doped Gd{sub 3}Al{sub 2}Ga{sub 3}O{sub 12} (Ce:GAGG), was employed, which has a relatively high density, a large light output, no natural radioactivity and no hygroscopicity. A 44 x 44 matrix of the Ce:GAGG pixels, with dimensions of 0.85 mm x 0.85 mm x 10 mm for each pixel, was coupled to a high-quantum efficiency position sensitive photomultiplier tube. This gamma detector unit was encased in a 20-mm-thick tungsten container with a tungsten pinhole collimator on the front. By using this gamma camera, soybean plants (Glycine max), grown in hydroponic solutions and fed with 1-2 MBq of Cs-137, were imaged for 6.5 days in maximum to investigate and visualize the uptake dynamics into/within the areal part. As a result, radiocesium gradually appeared in the shoot several hours after feeding of Cs-137, and then accumulated intensively in the maturing pods and seeds in a characteristic pattern. Our results also demonstrated that this gamma-camera method enables quantitative evaluation of plant ability to absorb, transport

  10. 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.

  11. 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

  12. Detection limits should be a thing of the past in gamma-ray spectrometry in general as well as in neutron activation analysis

    NARCIS (Netherlands)

    Blaauw, Menno

    2016-01-01

    In gamma-ray spectrometry with high-resolution detectors, full-energy peaks are often to be detected by a peak-search algorithm, with a threshold for detection. Detection limits can be derived from this. Detection limits are often computed along with measured activities or concentrations. When an

  13. Prepared for the thirtieth annual conference on bioassay analytical and environmental chemistry. Reliable analysis of high resolution gamma spectra

    International Nuclear Information System (INIS)

    Spitz, H.B.; Buschbom, R.; Rieksts, G.A.; Palmer, H.E.

    1985-01-01

    A new method has been developed to reliably analyze pulse height-energy spectra obtained from measurements employing high resolution germanium detectors. The method employs a simple data transformation and smoothing function to calculate background and identify photopeaks and isotopic analysis. This technique is elegant in its simplicity because it avoids dependence upon complex spectrum deconvolution, stripping, or other least-square-fitting techniques which complicate the assessment of measurement reliability. A moving median was chosen for data smoothing because, unlike moving averages, medians are not dominated by extreme data points. Finally, peaks are identified whenever the difference between the background spectrum and the transformed spectrum exceeds a pre-determined number of standard deviations

  14. Coupled multi-group neutron photon transport for the simulation of high-resolution gamma-ray spectroscopy applications

    Energy Technology Data Exchange (ETDEWEB)

    Burns, Kimberly A. [Georgia Inst. of Technology, Atlanta, GA (United States)

    2009-08-01

    The accurate and efficient simulation of coupled neutron-photon problems is necessary for several important radiation detection applications. Examples include the detection of nuclear threats concealed in cargo containers and prompt gamma neutron activation analysis for nondestructive determination of elemental composition of unknown samples.

  15. EXILL - a high-efficiency, high-resolution setup for gamma-spectroscopy at an intense cold neutron beam facility

    Czech Academy of Sciences Publication Activity Database

    Jentschel, M.; Blanc, A.; de France, G.; Koster, U.; Leoni, S.; Mutti, P.; Simpson, G. S.; Krtička, M.; Tomandl, Ivo; Valenta, S.

    2017-01-01

    Roč. 12, č. 11 (2017), č. článku P11003. ISSN 1748-0221 Institutional support: RVO:61389005 Keywords : instrumentation for neutron sources * gamma detectors * spectrometers Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Nuclear physics Impact factor: 1.220, year: 2016

  16. 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.

  17. Investigating the presence of omeprazole in waters by liquid chromatography coupled to low and high resolution mass spectrometry: degradation experiments.

    Science.gov (United States)

    Boix, C; Ibáñez, M; Sancho, J V; Niessen, W M A; Hernández, F

    2013-10-01

    Omeprazole is one of the most consumed pharmaceuticals around the world. However, this compound is scarcely detected in urban wastewater and surface water. The absence of this pharmaceutical in the aquatic ecosystem might be due to its degradation in wastewater treatment plants, as well as in receiving water. In this work, different laboratory-controlled degradation experiments have been carried out on surface water in order to elucidate generated omeprazole transformation products (TPs). Surface water spiked with omeprazole was subjected to hydrolysis, photo-degradation under both sunlight and ultraviolet radiation and chlorination. Analyses by liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (LC-QTOF MS) permitted identification of up to 17 omeprazole TPs. In a subsequent step, the TPs identified were sought in surface water and urban wastewater by LC-QTOF MS and by LC coupled to tandem mass spectrometry with triple quadrupole. The parent omeprazole was not detected in any of the samples, but four TPs were found in several water samples. The most frequently detected compound was OTP 5 (omeprazole sulfide), which might be a reasonable candidate to be included in monitoring programs rather than the parent omeprazole. Copyright © 2013 John Wiley & Sons, Ltd.

  18. Direct determination of acrylamide in food by gas chromatography-high-resolution time-of-flight mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Dunovska, Lenka [Institute of Chemical Technology, Department of Food Chemistry and Analysis, Technicka 3, 166 28 Prague 6 (Czech Republic); Cajka, Tomas [Institute of Chemical Technology, Department of Food Chemistry and Analysis, Technicka 3, 166 28 Prague 6 (Czech Republic); Hajslova, Jana [Institute of Chemical Technology, Department of Food Chemistry and Analysis, Technicka 3, 166 28 Prague 6 (Czech Republic)]. E-mail: jana.hajslova@vscht.cz; Holadova, Katerina [Institute of Chemical Technology, Department of Food Chemistry and Analysis, Technicka 3, 166 28 Prague 6 (Czech Republic)

    2006-09-25

    Simple and rapid gas chromatographic (GC) method employing a high-resolution time-of-flight mass analyzer that enables direct analysis (no derivatization) of acrylamide in various heat-processed foodstuffs has been developed and validated. Co-isolation of acrylamide precursors such as sugars and asparagine, constituting the risk of results overestimation due to additional formation of analyte in hot GC injector, is avoided by the extraction with n-propanol followed by solvent exchange to acetonitrile (MeCN). Introduction of a novel purification strategy, dispersive solid phase extraction, based on addition of primary-secondary amine (PSA) sorbent into deffated extract in MeCN, provides a significant reduction of some abundant matrix co-extracts (mainly free fatty acids). Isotope dilution technique (d{sub 3}-acrylamide as an internal standard) is employed for compensation of potential target analyte losses and/or matrix-inducted chromatographic response enhancement. Limits of quantifications (LOQs) ranged between 15 and 40 {mu}g kg{sup -1} and recoveries were between 97 and 108% depending on the examined food matrix. The repeatability of measurements (expressed as relative standard deviation, R.S.D.) was as low as 1.9% for potato crisps containing acrylamide at a level of 1 mg kg{sup -1}. Slightly higher values (R.S.D. < 4.0%) were achieved for breakfast cereals and crisp bread with approximately 10 times lower content of this processing contaminant. Trueness of results generated by this new method was demonstrated via FAPAS[reg] (Food Analysis Performance Assessment Scheme) interlaboratory proficiency tests.

  19. A Computational Drug Metabolite Detection Using the Stable Isotopic Mass-Shift Filtering with High Resolution Mass Spectrometry in Pioglitazone and Flurbiprofen

    Directory of Open Access Journals (Sweden)

    Yohei Miyamoto

    2013-09-01

    Full Text Available The identification of metabolites in drug discovery is important. At present, radioisotopes and mass spectrometry are both widely used. However, rapid and comprehensive identification is still laborious and difficult. In this study, we developed new analytical software and employed a stable isotope as a tool to identify drug metabolites using mass spectrometry. A deuterium-labeled compound and non-labeled compound were both metabolized in human liver microsomes and analyzed by liquid chromatography/time-of-flight mass spectrometry (LC-TOF-MS. We computationally aligned two different MS data sets and filtered ions having a specific mass-shift equal to masses of labeled isotopes between those data using our own software. For pioglitazone and flurbiprofen, eight and four metabolites, respectively, were identified with calculations of mass and formulas and chemical structural fragmentation analysis. With high resolution MS, the approach became more accurate. The approach detected two unexpected metabolites in pioglitazone, i.e., the hydroxypropanamide form and the aldehyde hydrolysis form, which other approaches such as metabolite-biotransformation list matching and mass defect filtering could not detect. We demonstrated that the approach using computational alignment and stable isotopic mass-shift filtering has the ability to identify drug metabolites and is useful in drug discovery.

  20. Identification of ortho-Substituted Benzoic Acid/Ester Derivatives via the Gas-Phase Neighboring Group Participation Effect in (+)-ESI High Resolution Mass Spectrometry.

    Science.gov (United States)

    Blincoe, William D; Rodriguez-Granillo, Agustina; Saurí, Josep; Pierson, Nicholas A; Joyce, Leo A; Mangion, Ian; Sheng, Huaming

    2018-04-01

    Benzoic acid/ester/amide derivatives are common moieties in pharmaceutical compounds and present a challenge in positional isomer identification by traditional tandem mass spectrometric analysis. A method is presented for exploiting the gas-phase neighboring group participation (NGP) effect to differentiate ortho-substituted benzoic acid/ester derivatives with high resolution mass spectrometry (HRMS 1 ). Significant water/alcohol loss (>30% abundance in MS 1 spectra) was observed for ortho-substituted nucleophilic groups; these fragment peaks are not observable for the corresponding para and meta-substituted analogs. Experiments were also extended to the analysis of two intermediates in the synthesis of suvorexant (Belsomra) with additional analysis conducted with nuclear magnetic resonance (NMR), density functional theory (DFT), and ion mobility spectrometry-mass spectrometry (IMS-MS) studies. Significant water/alcohol loss was also observed for 1-substituted 1, 2, 3-triazoles but not for the isomeric 2-substituted 1, 2, 3-triazole analogs. IMS-MS, NMR, and DFT studies were conducted to show that the preferred orientation of the 2-substituted triazole rotamer was away from the electrophilic center of the reaction, whereas the 1-subtituted triazole was oriented in close proximity to the center. Abundance of NGP product was determined to be a product of three factors: (1) proton affinity of the nucleophilic group; (2) steric impact of the nucleophile; and (3) proximity of the nucleophile to carboxylic acid/ester functional groups. Graphical Abstract ᅟ.

  1. Investigation of artifacts caused by deuterium background correction in the determination of phosphorus by electrothermal atomization using high-resolution continuum source atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Dessuy, Morgana B.; Vale, Maria Goreti R.; Lepri, Fabio G.; Borges, Daniel L.G.; Welz, Bernhard; Silva, Marcia M.; Heitmann, Uwe

    2008-01-01

    The artifacts created in the measurement of phosphorus at the 213.6-nm non-resonance line by electrothermal atomic absorption spectrometry using line source atomic absorption spectrometry (LS AAS) and deuterium lamp background correction (D 2 BC) have been investigated using high-resolution continuum source atomic absorption spectrometry (HR-CS AAS). The absorbance signals and the analytical curves obtained by LS AAS without and with D 2 BC, and with HR-CS AAS without and with automatic correction for continuous background absorption, and also with least-squares background correction for molecular absorption with rotational fine structure were compared. The molecular absorption due to the suboxide PO that exhibits pronounced fine structure could not be corrected by the D 2 BC system, causing significant overcorrection. Among the investigated chemical modifiers, NaF, La, Pd and Pd + Ca, the Pd modifier resulted in the best agreement of the results obtained with LS AAS and HR-CS AAS. However, a 15% to 100% higher sensitivity, expressed as slope of the analytical curve, was obtained for LS AAS compared to HR-CS AAS, depending on the modifier. Although no final proof could be found, the most likely explanation is that this artifact is caused by a yet unidentified phosphorus species that causes a spectrally continuous absorption, which is corrected without problems by HR-CS AAS, but which is not recognized and corrected by the D 2 BC system of LS AAS

  2. Some considerations on the use of gamma spectrometry for Kr-85 determination at gaseous effluents in the nuclear industry and environmental samples

    International Nuclear Information System (INIS)

    Heras Iniquez, M.C.; Perez Garcia, M.M.; Travesi, A.

    1983-01-01

    The possibilities of using high resolution gamma ray spectrometry with GeLi semiconductor detector for measured the 0.514 KeV gamma radiation of Kr-B5 la explored, The detection limit of Kr-85 for a measuring time is 4.10 - 4 μCi with a counting time of 1000 minutes in a GeLi detector with a 20% efficiency relative to the INa (Tl). It is concluded that the use of gamma ray spectrometry for measuring the Kr-85 is not useful for environmental samples, but it can be used for the Kr-85 effluents control in Nuclear Stations. (Author) 26 refs

  3. High resolution inelastic gamma-ray measurements with a white neutron source from 1 to 200 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, R.O.; Laymon, C.M.; Wender, S.A.

    1990-01-01

    Measurements of prompt gamma rays following neutron-induced reactions have recently been made at the spallation neutron source at the WNR target area of LAMPF using germanium detectors. These experiments provide extensive excitation function data for inelastic neutron scattering as well as for other reactions such as (n,{alpha}), (n,n{alpha}), (n,p), (n,np), (n,nnp) and (n,xn) for 1 {le} {times} {le} 11. The continuous energy coverage available from 1 MeV to over 200 MeV is ideal for excitation function measurements and greatly extends the energy range for such data. The results of these measurements will provide a database for interpretation of gamma-ray spectra from the planned Mars Observer mission, aid in radiation transport calculations, allow verification of nuclear reaction models, and improve the evaluated neutron reaction data base.

  4. High resolution inelastic gamma-ray measurements with a white neutron source from 1 to 200 MeV

    International Nuclear Information System (INIS)

    Nelson, R.O.; Laymon, C.M.; Wender, S.A.

    1990-01-01

    Measurements of prompt gamma rays following neutron-induced reactions have recently been made at the spallation neutron source at the WNR target area of LAMPF using germanium detectors. These experiments provide extensive excitation function data for inelastic neutron scattering as well as for other reactions such as (n,α), (n,nα), (n,p), (n,np), (n,nnp) and (n,xn) for 1 ≤ x ≤ 11. The continuous energy coverage available from 1 MeV to over 200 MeV is ideal for excitation function measurements and greatly extends the energy range for such data. The results of these measurements will provide a database for interpretation of gamma-ray spectra from the planned Mars Observer mission, aid in radiation transport calculations, allow verification of nuclear reaction models, and improve the evaluated neutron reaction data base

  5. Characterization of Organic Nitrate Formation in Limonene Secondary Organic Aerosol using High-Resolution Chemical Ionization Mass Spectrometry

    Science.gov (United States)

    Faxon, Cameron; Hammes, Julia; Peng, Jianfei; Hallquist, Mattias; Pathak, Ravi

    2016-04-01

    Previous work has shown that organic nitrates (RONO2) are prevalent in the boundary layer, and can contribute significantly to secondary organic aerosol formation. Monoterpenes, including limonene, have been shown to be precursors for the formation of these organic nitrates. Limonene has two double bonds, either of which may be oxidized by NO3 or O3. This leads to the generation of products that can subsequently condense or partition into the particle phase, producing secondary organic aerosol. In order to further elucidate the particle and gas phase product distribution of organic nitrates forming from the reactions of limonene and the nitrate radical (NO3), a series of experiments were performed in the Gothenburg Flow Reactor for Oxidation Studies at Low Temperatures (G-FROST), described by previous work. N2O5 was used as the source for NO3 and NO2, and a characterized diffusion source was used to introduce limonene into the flow reactor. All experiments were conducted in the absence of light, and the concentration of limonene was increased step-wise throughout each experiment to modify the ratio of N2O5to limonene. The experiments were conducted such that both limonene- and N2O5-limited regimes were present. Gas and particle phase products were measured using an iodide High-Resolution Time-of-Flight Mass Spectrometer (HR-ToF-CIMS) coupled to a Filter Inlet for Gases and AEROsols (FIGAERO, and particle size and SOA mass concentrations were derived using a Scanning Mobility Particle Sizer (SMPS). CIMS measurement techniques have previously been employed for the measurement of organic nitrate products of such compounds using multiple reagent ions. The use of this instrumentation allowed for the identification of chemical formulas for gas and particle phase species. The findings from the experiments will be presented in terms of the relative gas-particle partitioning of major products and the effects of N2O5/limonene ratios on product distributions. Additionally, a

  6. Setting up of a liquid chromatography-high resolution tandem mass spectrometry method for the detection of caseins in food. A comparison with ELISA method

    Directory of Open Access Journals (Sweden)

    Daniela Gastaldi

    2013-06-01

    Full Text Available Determination of caseins in food matrices is usually performed by using the competitiveenzyme- linked immunosorbent assay (ELISA technique. However such a technique suffers from a number of limitations. Among these, the applicability to a narrow concentration range, a non linear (logarithmic response, a non-negligible cross-reactivity and a high cost per kit. At the time of the completion of this study, in case of ELISA positive feedback, there was poor availability in the literature of finding reliable instrumental methods able to determine both qualitatively and quantitatively this class of substances. In the present study, a liquid chromatography-high resolution tandem mass spectrometry (HPLC-HRMS/MS instrumental method was developed with a high resolution mass spectrometer (Orbitrap. Real samples of sausages in which caseins were detected by ELISA technique were analysed. A casein-free sample of ham was used as a blank. The analytical characteristics of the instrumental method were compared with those of a commercial ELISA test, declared specific for α- and β-casein.

  7. Tentative identification of polar and mid-polar compounds in extracts from wine lees by liquid chromatography-tandem mass spectrometry in high-resolution mode.

    Science.gov (United States)

    Delgado de la Torre, M P; Priego-Capote, F; Luque de Castro, M D

    2015-06-01

    Sustainable agriculture has a pending goal in the revalorization of agrofood residues. Wine lees are an abundant residue in the oenological industry. This residue, so far, has been used to obtain tartaric acid or pigments but not for being qualitatively characterized as a source of polar and mid-polar compounds such as flavonoids, phenols and essential amino acids. Lees extracts from 11 Spanish wineries have been analyzed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) in high resolution mode. The high-resolution power of LC-MS/MS has led to the tentative identification of the most representative compounds present in wine lees, comprising primary amino acids, anthocyans, flavanols, flavonols, flavones and non-flavonoid phenolic compounds, among others. Attending to the profile and content of polar and mid-polar compounds in wine lees, this study underlines the potential of wine lees as an exploitable source to isolate interesting compounds. Copyright © 2015 John Wiley & Sons, Ltd.

  8. Impurity profiling of liothyronine sodium by means of reversed phase HPLC, high resolution mass spectrometry, on-line H/D exchange and UV/Vis absorption.

    Science.gov (United States)

    Ruggenthaler, M; Grass, J; Schuh, W; Huber, C G; Reischl, R J

    2017-09-05

    For the first time, a comprehensive investigation of the impurity profile of the synthetic thyroid API (active pharmaceutical ingredient) liothyronine sodium (LT 3 Na) was performed by using reversed phase HPLC and advanced structural elucidation techniques including high resolution tandem mass spectrometry (HRMS/MS) and on-line hydrogen-deuterium (H/D) exchange. Overall, 39 compounds were characterized and 25 of these related substances were previously unknown to literature. The impurity classification system recently developed for the closely related API levothyroxine sodium (LT 4 Na) could be applied to the newly characterized liothyronine sodium impurities resulting in a wholistic thyroid API impurity classification system. Furthermore, the mass-spectrometric CID-fragmentation of specific related substances was discussed and rationalized by detailed fragmentation pathways. Moreover, the UV/Vis absorption characteristics of the API and selected impurities were investigated to corroborate chemical structure assignments derived from MS data. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Fast and sensitive analysis of beta blockers by ultra-high-performance liquid chromatography coupled with ultra-high-resolution TOF mass spectrometry.

    Science.gov (United States)

    Tomková, Jana; Ondra, Peter; Kocianová, Eva; Václavík, Jan

    2017-07-01

    This paper presents a method for the determination of acebutolol, betaxolol, bisoprolol, metoprolol, nebivolol and sotalol in human serum by liquid-liquid extraction and ultra-high-performance liquid chromatography coupled with ultra-high-resolution TOF mass spectrometry. After liquid-liquid extraction, beta blockers were separated on a reverse-phase analytical column (Acclaim RS 120; 100 × 2.1 mm, 2.2 μm). The total run time was 6 min for each sample. Linearity, limit of detection, limit of quantification, matrix effects, specificity, precision, accuracy, recovery and sample stability were evaluated. The method was successfully applied to the therapeutic drug monitoring of 108 patients with hypertension. This method was also used for determination of beta blockers in 33 intoxicated patients. Copyright © 2016 John Wiley & Sons, Ltd.

  10. HighResNPS.com – an Internet Database for Liquid Chromatography - High Resolution Mass Spectrometry Screening for New Psychoactive Substances

    DEFF Research Database (Denmark)

    Dalsgaard, Petur Weihe; Mollerup, Christian Brinch; Mardal, Marie

    /Discussions: . The overlapping entries of the database verify that similar fragment ions can be observed from identical compounds across different LC-HRMS systems. The inclusion of fragment ions from other labs can reduce false positive identifications, when no reference standard is available in-house. HighResNPS can serve......Background/Introduction: The number of new psychoactive substances (NPS) is constantly increasing which makes it challenging to keep the screening libraries updated with the relevant analytical targets. Liquid chromatography coupled High Resolution Mass Spectrometry (LC-HRMS) screening methods...... with most screening platforms after minor formatting. Results: Currently, 11 users from 9 laboratories in 7 counties have contributed with 318 entries to the database with experimental data containing at least one fragment ion. 66% of the uploaded data were based on reference standards. Synthetic...

  11. Exploring the potential of high resolution mass spectrometry for the investigation of lignin-derived phenol substitutes in phenolic resin syntheses.

    Science.gov (United States)

    Dier, Tobias K F; Fleckenstein, Marco; Militz, Holger; Volmer, Dietrich A

    2017-05-01

    Chemical degradation is an efficient method to obtain bio-oils and other compounds from lignin. Lignin bio-oils are potential substitutes for the phenol component of phenol formaldehyde (PF) resins. Here, we developed an analytical method based on high resolution mass spectrometry that provided structural information for the synthesized lignin-derived resins and supported the prediction of their properties. Different model resins based on typical lignin degradation products were analyzed by electrospray ionization in negative ionization mode. Utilizing enhanced mass defect filter techniques provided detailed structural information of the lignin-based model resins and readily complemented the analytical data from differential scanning calorimetry and thermogravimetric analysis. Relative reactivity and chemical diversity of the phenol substitutes were significant determinants of the outcome of the PF resin synthesis and thus controlled the areas of application of the resulting polymers. Graphical abstract ᅟ.

  12. Triple Quadrupole Versus High Resolution Quadrupole-Time-of-Flight Mass Spectrometry for Quantitative LC-MS/MS Analysis of 25-Hydroxyvitamin D in Human Serum

    Science.gov (United States)

    Geib, Timon; Sleno, Lekha; Hall, Rabea A.; Stokes, Caroline S.; Volmer, Dietrich A.

    2016-08-01

    We describe a systematic comparison of high and low resolution LC-MS/MS assays for quantification of 25-hydroxyvitamin D3 in human serum. Identical sample preparation, chromatography separations, electrospray ionization sources, precursor ion selection, and ion activation were used; the two assays differed only in the implemented final mass analyzer stage; viz. high resolution quadrupole-quadrupole-time-of-flight (QqTOF) versus low resolution triple quadrupole instruments. The results were assessed against measured concentration levels from a routine clinical chemiluminescence immunoassay. Isobaric interferences prevented the simple use of TOF-MS spectra for extraction of accurate masses and necessitated the application of collision-induced dissociation on the QqTOF platform. The two mass spectrometry assays provided very similar analytical figures of merit, reflecting the lack of relevant isobaric interferences in the MS/MS domain, and were successfully applied to determine the levels of 25-hydroxyvitamin D for patients with chronic liver disease.

  13. Identification/quantification of free and bound phenolic acids in peel and pulp of apples (Malus domestica) using high resolution mass spectrometry (HRMS).

    Science.gov (United States)

    Lee, Jihyun; Chan, Bronte Lee Shan; Mitchell, Alyson E

    2017-01-15

    Free and bound phenolic acids were measured in the pulp and peel of four varieties of apples using high resolution mass spectrometry. Twenty-five phenolic acids were identified and included: 8 hydroxybenzoic acids, 11 hydroxycinnamic acids, 5 hydroxyphenylacetic acids, and 1 hydoxyphenylpropanoic acid. Several phenolics are tentatively identified for the first time in apples and include: methyl gallate, ethyl gallate, hydroxy phenyl acetic acid, three phenylacetic acid isomers, 3-(4-hydroxyphenyl)propionic acid, and homoveratric acid. With exception of chlorogenic and caffeic acid, most phenolic acids were quantified for the first time in apples. Significant varietal differences (pacids were higher in the pulp as compared to apple peel (dry weight) in all varieties. Coumaroylquinic, protocatechuic, 4-hydroxybenzoic, vanillic and t-ferulic acids were present in free forms. With exception of chlorogenic acid, all other phenolic acids were present only as bound forms. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. An Investigation of the Complexity of Maillard Reaction Product Profiles from the Thermal Reaction of Amino Acids with Sucrose Using High Resolution Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Agnieszka Golon

    2014-08-01

    Full Text Available Thermal treatment of food changes its chemical composition drastically with the formation of “so-called” Maillard reaction products, being responsible for the sensory properties of food, along with detrimental and beneficial health effects. In this contribution, we will describe the reactivity of several amino acids, including arginine, lysine, aspartic acid, tyrosine, serine and cysteine, with carbohydrates. The analytical strategy employed involves high and ultra-high resolution mass spectrometry followed by chemometric-type data analysis. The different reactivity of amino acids towards carbohydrates has been observed with cysteine and serine, resulting in complex MS spectra with thousands of detectable reaction products. Several compounds have been tentatively identified, including caramelization reaction products, adducts of amino acids with carbohydrates, their dehydration and hydration products, disproportionation products and aromatic compounds based on molecular formula considerations.

  15. Identification of Organic Iodine Compounds and Their Transformation Products in Edible Iodized Salt Using Liquid Chromatography-High Resolution Mass Spectrometry.

    Science.gov (United States)

    Yun, Lifen; Peng, Yue'e; Chang, Qing; Zhu, Qingxin; Guo, Wei; Wang, Yanxin

    2017-07-05

    The consumption of edible iodized salt is a key strategy to control and eliminate iodine deficiency disorders worldwide. We herein report the identification of the organic iodine compounds present in different edible iodized salt products using liquid chromatography combined with high resolution mass spectrometry. A total of 38 organic iodine compounds and their transformation products (TPs) were identified in seaweed iodine salt from China. Our experiments confirmed that the TPs were generated by the replacement of I atoms from organic iodine compounds with Cl atoms. Furthermore, the organic iodine compound contents in 4 seaweed iodine salt samples obtained from different manufacturers were measured, with significant differences in content being observed. We expect that the identification of organic iodine compounds in salt will be important for estimating the validity and safety of edible iodized salt products.

  16. High Resolution X-ray Diffraction Dataset for Bacillus licheniformis Gamma Glutamyl Transpeptidase-acivicin complex: SUMO-Tag Renders High Expression and Solubility.

    Science.gov (United States)

    Kumari, Shobha; Pal, Ravi Kant; Gupta, Rani; Goel, Manisha

    2017-02-01

    Gamma glutamyl transpeptidase, (GGT) is a ubiquitous protein which plays a central role in glutathione metabolism and has myriad clinical implications. It has been shown to be a virulence factor for pathogenic bacteria, inhibition of which results in reduced colonization potential. However, existing inhibitors are effective but toxic and therefore search is on for novel inhibitors, which makes it imperative to understand the interactions of various inhibitors with the protein in substantial detail. High resolution structures of protein bound to different inhibitors can serve this purpose. Gamma glutamyl transpeptidase from Bacillus licheniformis is one of the model systems that have been used to understand the structure-function correlation of the protein. The structures of the native protein (PDB code 4OTT), of its complex with glutamate (PDB code 4OTU) and that of its precursor mimic (PDB code 4Y23) are available, although at moderate/low resolution. In the present study, we are reporting the preliminary analysis of, high resolution X-ray diffraction data collected for the co-crystals of B. licheniformis, Gamma glutamyl transpeptidase, with its inhibitor, Acivicin. Crystals belong to the orthorhombic space group P2 1 2 1 2 1 and diffract X-ray to 1.45 Å resolution. This is the highest resolution data reported for all GGT structures available till now. The use of SUMO fused expression system enhanced yield of the target protein in the soluble fraction, facilitating recovery of protein with high purity. The preliminary analysis of this data set shows clear density for the inhibitor, acivicin, in the protein active site.

  17. Simultaneous use of 82Br and 24Na radionuclides in the whole-body counting of animals by high-resolution gamma-ray spektrometry

    Czech Academy of Sciences Publication Activity Database

    Pavelka, Stanislav; Babický, Arnošt; Vobecký, Miloslav

    2008-01-01

    Roč. 278, č. 3 (2008), s. 571-574 ISSN 0236-5731 Grant - others:EC(XE) LSHG-CT-2004-511978 Institutional research plan: CEZ:AV0Z50110509; CEZ:AV0Z40310501 Keywords : gamma-spectrometry * whole-body counting * radionuclide Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.659, year: 2008

  18. Rapid profiling of antimicrobial compounds characterising B. subtilis TR50 cell-free filtrate by high-performance liquid chromatography coupled to high-resolution Orbitrap™ mass spectrometry.

    Science.gov (United States)

    Monaci, Linda; Quintieri, Laura; Caputo, Leonardo; Visconti, Angelo; Baruzzi, Federico

    2016-01-15

    Several Bacillus strains, typically isolated from different food sources, represent renowned producers of a multitude of low and high molecular weight compounds, including lipopeptides and macrolactones, with an importance for their antimicrobial activity. The high homology shared by many of these compounds also occurring as closely related isoforms poses a challenge in their prompt detection. Identification and structural elucidation is generally achieved by matrix-assisted laser desorption/ionization (MALDI) or liquid chromatography (LC) coupled to mass spectrometry (MS) after a pre-fractionation and/or purification step of the extract. In this paper we report the application of a method based on LC separation and high-resolution Orbitrap™-based MS for the rapid screening of raw filtrate of the strain Bacillus subtilis TR50 endowed with antimicrobial activity, without requiring any sample pre-treatment. Upon direct analysis of the cell-free filtrate of Bacillus subtilis TR50 by high-resolution mass spectrometry (HRMS), different compounds families, that proved to exert a remarked antimicrobial activity against several foodborne pathogens, can be readily displayed along the chromatographic run. Among them, three different classes were identified and characterized belonging to the iturin, fengycin and surfactin groups. The high resolving power and accurate mass accuracy provided by the HRMS system in use ensured an enhanced selectivity compared to other mass spectrometers. In addition, after activation of the HCD cell, the HR-MS/MS spectra can provide insights in the structural elucidation of several compounds. The acquisition of HRMS spectra of raw filtrates of subtilis strains allows untargeted analysis of the major classes of compounds produced to be performed, thus facilitating identification of other unknown bioactive molecules after retrospective analysis. These features make this approach a fast tool applicable to the rapid screening and further

  19. Multi-allergen quantification of fining-related egg and milk proteins in white wines by high-resolution mass spectrometry.

    Science.gov (United States)

    Monaci, Linda; Losito, Ilario; De Angelis, Elisabetta; Pilolli, Rosa; Visconti, Angelo

    2013-09-15

    A method based on High-Resolution Mass Spectrometry was developed for the simultaneous determination of fining agents containing potentially allergenic milk (casein) and egg-white (lysozyme and ovalbumin) proteins, added to commercial white wines at sub-ppm levels. Selected tryptic peptides were used as quantitative markers. An evaluation of protein digestion yields was also performed by implementing the (15)N-valine-labelled analogues of the best peptide markers identified for αS1 -casein and ovalbumin. The method was based on the combination of ultrafiltration (UF) of protein-containing wines, tryptic digestion of the dialyzed wine extracts and liquid chromatography/high resolution mass spectrometry (LC/HRMS) analysis of tryptic digests. Peptides providing the most intense electrospray ionization (ESI)-MS response were chosen as quantitative markers of the proteins under investigation. Six-point calibrations were performed by adding caseinate and egg-white powder in the concentration range between 0.25 and 10 µg/mL, to an allergen-free white wine. The following three peptide markers, LTEWTSSNVMEER, GGLEPINFQTAADQAR and ELINSWVESQTNGIIR, were highlighted as best markers for ovalbumin, while GTDVQAWIR and NTDGSTDYGILQINSR for lysozyme and YLGYLEQLLR, GPFPIIV and FFVAPFPEVFGK for caseinate. Limits of detection (LODs) ranged from 0.4 to 1.1 µg/mL. The developed method is suited for assessing the contemporary presence of allergenic milk and egg proteins characterizing egg white and caseinate, fining agents typically employed for wine clarification. The LODs of the method enable the detection of sub-ppm concentrations of residual fining agents, that could represent a potential risk for allergic consumers. Copyright © 2013 John Wiley & Sons, Ltd.

  20. High resolution studies by Secondary Ion Mass Spectrometry of the spatial distribution of tritium in neutron irradiated beryllium pebbles

    International Nuclear Information System (INIS)

    Rabaglino, E.; Tamborini, G.; Hiernaut, J.-P.; Betti, M.

    2006-01-01

    A key issue of beryllium as a neutron multiplier in the blanket of future fusion reactors is tritium retention. Models are under development in order to predict tritium release kinetics in the typical operating conditions of the material in the blanket: the absence of experimental data in this range imposes an extrapolation of the models, therefore a detailed characterization and understanding of microscopic diffusion phenomena related to macroscopic tritium release is necessary. It has been recently shown, that the availability of evidence on such phenomena at a scale of 1 micron down to tens of nanometers enables a relevant progress in the effectiveness of model validation: therefore the need for applying and developing advanced analytical techniques based on mass spectrometry at this scale. A study of tritium spatial distribution in neutron irradiated beryllium pebbles (2 mm diameter, 480 appm 4 He, 7 appm 3 H) by means of Secondary Ion Mass Spectrometry (SIMS) is presented. Samples in different conditions (non-irradiated, at end of irradiation and at different temperatures during thermal ramp annealing) are examined by an oxygen ion primary beam with a spatial resolution of 1 micron along a diameter. The sample preparation is optimized in order to enable a quantitative comparison among the different conditions. Under an oxygen ion beam tritium is detected in the irradiated samples in a molecular form (3H 2 ), with a continuous distribution inside the grains, which suggests the presence of small clusters in agreement with TEM analyses, and in the form of peaks at grain boundaries, corresponding to large grain boundary bubbles. The evolving of molecular tritium distribution measured by SIMS during a typical thermal ramp release experiment shows precisely tritium diffusion from the centre of the grain to grain boundaries as the temperature increases: at the same time the remaining intragranular tritium inventory, given by the integral of the distribution

  1. Analysis of polychlorinated dibenzo-p-dioxins and dibenzofurans using simultaneous dual gas chromatography-high resolution mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Tirler, W.; Voto, G.; Donega, M. [Eco-Research, Bolzano (Italy)

    2004-09-15

    Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/F) are two classes of environmental contaminants. Seventeen congeners exist that are substituted in the 2,3,7,8 position and are considered to be the most toxic. Due to the large number (210) of compounds of the PCDD/F family, gas chromatographic (GC) separation of these from the cluster of less toxic isomers is a difficult task. At present no commercially available column can separate all 2,3,7,8 substituted congeners from the remaining PCDD/F. The co elution of less toxic with toxic congeners can cause false TEQ related results, because mass spectrometry cannot differentiate between toxic and non toxic congeners within the same homologous group. To overcome this, the analysis is performed using at least two capillary GC columns, of different polarity. Non polar columns can separate chlorine homologous groups and all toxic congeners from each other but not from all nontoxic congeners. Thus, a polar column should be used in addition for specific separation. Exchange of a GC column on a HRGC-HRMS system is usually a time consuming procedure. Significant time saving can be achieved using a mass spectrometer coupled to two GCs, that allows switching between two different GC columns, without disturbing the measurement conditions of the mass spectrometer. The aim of the present work was to develop a method that permits to work simultaneously with both GCs in order to further improve time savings.

  2. Metabolism of clofibric acid in zebrafish embryos (Danio rerio) as determined by liquid chromatography-high resolution-mass spectrometry.

    Science.gov (United States)

    Brox, Stephan; Seiwert, Bettina; Haase, Nora; Küster, Eberhard; Reemtsma, Thorsten

    2016-01-01

    The zebrafish embryo (ZFE) is increasingly used in ecotoxicology research but detailed knowledge of its metabolic potential is still limited. This study focuses on the xenobiotic metabolism of ZFE at different life-stages using the pharmaceutical compound clofibric acid as study compound. Liquid chromatography with quadrupole-time-of-flight mass spectrometry (LC-QToF-MS) is used to detect and to identify the transformation products (TPs). In screening experiments, a total of 18 TPs was detected and structure proposals were elaborated for 17 TPs, formed by phase I and phase II metabolism. Biotransformation of clofibric acid by the ZFE involves conjugation with sulfate or glucuronic acid, and, reported here for the first time, with carnitine, taurine, and aminomethanesulfonic acid. Further yet unknown cyclization products were identified using non-target screening that may represent a new detoxification pathway. Sulfate containing TPs occurred already after 3h of exposure (7hpf), and from 48h of exposure (52hpf) onwards, all TPs were detected. The detection of these TPs indicates the activity of phase I and phase II enzymes already at early life-stages. Additionally, the excretion of one TP into the exposure medium was observed. The results of this study outline the high metabolic potential of the ZFE with respect to the transformation of xenobiotics. Similarities but also differences to other test systems were observed. Biotransformation of test chemicals in toxicity testing with ZFE may therefore need further consideration. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Ganglioside Composition in Beef, Chicken, Pork, and Fish Determined Using Liquid Chromatography-High-Resolution Mass Spectrometry.

    Science.gov (United States)

    Fong, Bertram Y; Ma, Lin; Khor, Geok Lin; van der Does, Yvonne; Rowan, Angela; McJarrow, Paul; MacGibbon, Alastair K H

    2016-08-17

    Gangliosides (GA) are found in animal tissues and fluids, such as blood and milk. These sialo-glycosphingolipids have bioactivities in neural development, the gastrointestinal tract, and the immune system. In this study, a high-performance liquid chromatography-mass spectrometry (HPLC-MS) method was validated to characterize and quantitate the GA in beef, chicken, pork, and fish species (turbot, snapper, king salmon, and island mackerel). For the first time, we report the concentration of GM3, the dominant GA in these foods, as ranging from 0.35 to 1.1 mg/100 g and 0.70 to 5.86 mg/100 g of meat and fish, respectively. The minor GAs measured were GD3, GD1a, GD1b, and GT1b. Molecular species distribution revealed that the GA contained long- to very-long-chain acyl fatty acids attached to the ceramide moiety. Fish GA contained only N-acetylneuraminic acid (NeuAc) sialic acid, while beef, chicken, and pork contained GD1a/b species that incorporated both NeuAc and N-glycolylneuraminic acid (NeuGc) and hydroxylated fatty acids.

  4. Ultra-high-performance liquid chromatography-Time-of-flight high resolution mass spectrometry to quantify acidic drugs in wastewater.

    Science.gov (United States)

    Becerra-Herrera, Mercedes; Honda, Luis; Richter, Pablo

    2015-12-04

    A novel analytical approach involving an improved rotating-disk sorptive extraction (RDSE) procedure and ultra-high-performance liquid chromatography (UHPLC) coupled to an ultraspray electrospray ionization source (UESI) and time-of-flight mass spectrometry (TOF/MS), in trap mode, was developed to identify and quantify four non-steroidal anti-inflammatory drugs (NSAIDs) (naproxen, ibuprofen, ketoprofen and diclofenac) and two anti-cholesterol drugs (ACDs) (clofibric acid and gemfibrozil) that are widely used and typically found in water samples. The method reduced the amount of both sample and reagents used and also the time required for the whole analysis, resulting in a reliable and green analytical strategy. The analytical eco-scale was calculated, showing that this methodology is an excellent green analysis, increasing its ecological worth. The detection limits (LOD) and precision (%RSD) were lower than 90ng/L and 10%, respectively. Matrix effects and recoveries were studied using samples from the influent of a wastewater treatment plant (WWTP). All the compounds exhibited suppression of their signals due to matrix effects, and the recoveries were approximately 100%. The applicability and reliability of this methodology were confirmed through the analysis of influent and effluent samples from a WWTP in Santiago, Chile, obtaining concentrations ranging from 1.1 to 20.5μg/L and from 0.5 to 8.6μg/L, respectively. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Profiling of Histone Post-Translational Modifications in Mouse Brain with High-Resolution Top-Down Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Mowei; Paša-Tolić, Ljiljana; Stenoien, David L.

    2016-12-21

    Histones play central roles in most chromosomal functions and both their basic biology and roles in disease have been the subject of intense study. Since multiple PTMs along the entire protein sequence are potential regulators of histones, a top-down approach, where intact proteins are analyzed, is ultimately required for complete characterization of proteoforms. However, significant challenges remain for top-down histone analysis primarily because of deficiencies in separation/resolving power and effective identification algorithms. Here, we used state of the art mass spectrometry and a bioinformatics workflow for targeted data analysis and visualization. The workflow uses ProMex for intact mass deconvolution, MSPathFinder as search engine, and LcMsSpectator as a data visualization tool. ProMex sums across retention time to maximize sensitivity and accuracy for low abundance species in MS1deconvolution. MSPathFinder searches the MS2 data against protein sequence databases with user-defined modifications. LcMsSpectator presents the results from ProMex and MSPathFinder in a format that allows quick manual evaluation of critical attributes for high-confidence identifications. When complemented with the open-modification tool TopPIC, this workflow enabled identification of novel histone PTMs including tyrosine bromination on histone H4 and H2A, H3 glutathionylation, and mapping of conventional PTMs along the entire protein for many histone subunits.

  6. Rapid Classification and Identification of Multiple Microorganisms with Accurate Statistical Significance via High-Resolution Tandem Mass Spectrometry.

    Science.gov (United States)

    Alves, Gelio; Wang, Guanghui; Ogurtsov, Aleksey Y; Drake, Steven K; Gucek, Marjan; Sacks, David B; Yu, Yi-Kuo

    2018-06-05

    Rapid and accurate identification and classification of microorganisms is of paramount importance to public health and safety. With the advance of mass spectrometry (MS) technology, the speed of identification can be greatly improved. However, the increasing number of microbes sequenced is complicating correct microbial identification even in a simple sample due to the large number of candidates present. To properly untwine candidate microbes in samples containing one or more microbes, one needs to go beyond apparent morphology or simple "fingerprinting"; to correctly prioritize the candidate microbes, one needs to have accurate statistical significance in microbial identification. We meet these challenges by using peptide-centric representations of microbes to better separate them and by augmenting our earlier analysis method that yields accurate statistical significance. Here, we present an updated analysis workflow that uses tandem MS (MS/MS) spectra for microbial identification or classification. We have demonstrated, using 226 MS/MS publicly available data files (each containing from 2500 to nearly 100,000 MS/MS spectra) and 4000 additional MS/MS data files, that the updated workflow can correctly identify multiple microbes at the genus and often the species level for samples containing more than one microbe. We have also shown that the proposed workflow computes accurate statistical significances, i.e., E values for identified peptides and unified E values for identified microbes. Our updated analysis workflow MiCId, a freely available software for Microorganism Classification and Identification, is available for download at https://www.ncbi.nlm.nih.gov/CBBresearch/Yu/downloads.html . Graphical Abstract ᅟ.

  7. Normalization to specific gravity prior to analysis improves information recovery from high resolution mass spectrometry metabolomic profiles of human urine.

    Science.gov (United States)

    Edmands, William M B; Ferrari, Pietro; Scalbert, Augustin

    2014-11-04

    Extraction of meaningful biological information from urinary metabolomic profiles obtained by liquid-chromatography coupled to mass spectrometry (MS) necessitates the control of unwanted sources of variability associated with large differences in urine sample concentrations. Different methods of normalization either before analysis (preacquisition normalization) through dilution of urine samples to the lowest specific gravity measured by refractometry, or after analysis (postacquisition normalization) to urine volume, specific gravity and median fold change are compared for their capacity to recover lead metabolites for a potential future use as dietary biomarkers. Twenty-four urine samples of 19 subjects from the European Prospective Investigation into Cancer and nutrition (EPIC) cohort were selected based on their high and low/nonconsumption of six polyphenol-rich foods as assessed with a 24 h dietary recall. MS features selected on the basis of minimum discriminant selection criteria were related to each dietary item by means of orthogonal partial least-squares discriminant analysis models. Normalization methods ranked in the following decreasing order when comparing the number of total discriminant MS features recovered to that obtained in the absence of normalization: preacquisition normalization to specific gravity (4.2-fold), postacquisition normalization to specific gravity (2.3-fold), postacquisition median fold change normalization (1.8-fold increase), postacquisition normalization to urinary volume (0.79-fold). A preventative preacquisition normalization based on urine specific gravity was found to be superior to all curative postacquisition normalization methods tested for discovery of MS features discriminant of dietary intake in these urinary metabolomic datasets.

  8. In situ gamma-ray spectrometry: A tutorial for environmental radiation scientists

    International Nuclear Information System (INIS)

    Miller, K.M.; Shebell, P.

    1993-10-01

    This tutorial is intended for those in the environmental field who perform assessments in areas where there is radioactive contamination in the surface soil. Techniques will be introduced for performing on-site quantitative measurements of gamma radiation in the environment using high resolution germanium detectors. A basic understanding of ionizing radiation principles is assumed; however, a detailed knowledge of gamma spectrometry systems is not required. Emphasized is the practical end of operations in the field and the conversion of measured full absorption peak count rates in a collected spectrum to meaningful radiological quantities, such as the concentration of a radionuclide in the soil, activity per unit area, and dose rate in the air. The theory of operation and calibration procedures will be covered in detail to provide the necessary knowledge to adapt the technique to site-specific problems. Example calculations for detector calibration are also provided

  9. Development of a new screening method for the detection of antibiotic residues in muscle tissues using liquid chromatography and high resolution mass spectrometry with a LC-LTQ-Orbitrap instrument.

    OpenAIRE

    2011-01-01

    Abstract In the present work, a liquid chromatography- high resolution mass spectrometry method was developed for the screening in meat of a wide range of antibiotics used in veterinary medicine. Full scan mode under high resolution mass spectral conditions using LTQ-Orbitrap mass spectrometer with resolving power 60.000 FWHM was applied for analysis of the samples. Samples were prepared using two extractions protocols prior to LC-MS analysis. The scope of the method focuses on the...

  10. High-throughput screening and confirmation of 22 banned veterinary drugs in feedstuffs using LC-MS/MS and high-resolution Orbitrap mass spectrometry.

    Science.gov (United States)

    Wang, Xufeng; Liu, Yanghong; Su, Yijuan; Yang, Jianwen; Bian, Kui; Wang, Zongnan; He, Li-Min

    2014-01-15

    A new analytical strategy based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) combined with accurate mass high-resolution Orbitrap mass spectrometry (HR-Orbitrap MS) was performed for high-throughput screening, confirmation, and quantification of 22 banned or unauthorized veterinary drugs in feedstuffs according to Bulletin 235 of the Ministry of Agriculture, China. Feed samples were extracted with acidified acetonitrile, followed by cleanup using solid-phase extraction cartridge. The extracts were first screened by LC-MS/MS in a single selected reaction monitoring mode. The suspected positive samples were subjected to a specific pretreatment for confirmation and quantification of analyte of interest with LC-MS/MS and HR-Orbitrap MS. Mean recoveries for all target analytes (except for carbofuran and chlordimeform, which were about 35 and 45%, respectively) ranged from 52.2 to 90.4%, and the relative standard deviations were screening of real samples obtained from local feed markets and confirmation of the suspected target analytes. It provides a high-throughput, sensitive, and reliable screening, identification, and quantification of banned veterinary drugs in routine monitoring programs of feedstuffs.

  11. Liquid chromatography with high resolution mass spectrometry for identification of organic contaminants in fish fillet: screening and quantification assessment using two scan modes for data acquisition.

    Science.gov (United States)

    Munaretto, Juliana S; May, Marília M; Saibt, Nathália; Zanella, Renato

    2016-07-22

    This study proposed a strategy to identify and quantify 182 organic contaminants from different chemical classes, as for instance pesticides, veterinary drug and personal care products, in fish fillet using liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (LC-QToF/MS). For this purpose, two different scan methods (full scan and all ions MS/MS) were evaluated to assess the best option for screening analysis in spiked fish fillet samples. In general, full scan acquisition was found to be more reliable (84%) in the automatic identification and quantification when compared to all ions MS/MS with 72% of the compounds detected. Additionally, a qualitative automatic search showed a mass accuracy error below 5ppm for 77% of the compounds in full scan mode compared to only 52% in all ions MS/MS scan. However, all ions MS/MS provides fragmentation information of the target compounds. Undoubtedly, structural information of a wide number of compounds can be obtained using high resolution mass spectrometry (HRMS), but it is necessary thoroughly assess it, in order to choose the best scan mode. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. The effect of energy peak drift on the calibration of a high resolution gamma-ray soil density gauge

    International Nuclear Information System (INIS)

    Henshall, J.K.

    1994-01-01

    High spatial resolution is obtained from a gamma-ray transmission density gauge by restricting the measured counts to a narrow band of the energy spectrum, close to the emission energy peak. The effect on measurement accuracy of any movement of this measurement window relative to the energy peak was investigated. The findings were related to anticipated energy peak movements in a proposed LED-based gain-stabilization system. Movements of the energy peaks during recording of unstabilized spectra prevented direct comparisons of spectra at different positions. A simulation procedure was, therefore, developed in which movements of the measurement window relative to sets of stable calibration spectra were examined. When analysing spectra, recorded using a gauge with a different gain-stabilization system, accuracy was found to be unaffected by simulated peak movements of up to 0.03 MeV in the direction of increasing energy. However, movements of stabilized spectra in the direction of decreasing energy, and of unstabilized spectra in either direction, increased measurement errors to twice the level of inherent measurement errors within 0.02 MeV, with errors in bulk density of up to 0.7 Mg m −3 for movements of 0.1 MeV. The spectra of the new LED-based stabilization system are expected to behave in a manner similar to the unstabilized system, therefore requiring regular monitoring of the peak position. (author)

  13. Application of high resolution NMR, ESR, and gamma-ray scintillation spectroscopy to the study of ligand binding in proteins

    International Nuclear Information System (INIS)

    Lancione, G.V.

    1982-01-01

    Electron spin resonance spectroscopy has been employed to study the nature of the ligand binding site of alpha-1-antitrypsin. Spectra of spin-labeled alpha-1-antitrypsin were recorded at pH's ranging from 2.4 to 12.5. This data demonstrates the tight binding of the spin-label to the protease, and the sensitivity of the bound spin-label to informational changes in the protease inhibitor. A molecular dipstick approach has also been applied to this system and has yielded information on the geometry of the cleft accommodating the spin-label. 160 Terbium(III) exchange experiments have been performed on the acetylcholine receptor protein isolated from Torpedo californica, employing a specially designed flow dialysis apparatus constructed in the laboratory. The apparatus is designed to allow continuous monitoring of 160 Tb(III) gamma-ray emission from the protein compartment of the flow dialysis cell. Nicotinic ligand-induced displacement of 160 Tb(III) from the nicotinic binding site of the receptor was monitored as a funtion of (1) the concentration of nicotinic ligand in the washout buffer, and (2) the nature of the nicotinic ligand in the buffer. Measured 160 Tb(III) exchange half-lives indicate (1) a direct relationship between 160 Tb(III) displacement and nicotinic ligand concentration in the wash-out buffer, and (2) an enhanced 160 Tb(III) displacement for nicotinic agents possessing quaternary ammonium functions

  14. Occult Breast Cancer: Scintimammography with High-Resolution Breast-specific Gamma Camera in Women at High Risk for Breast Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Rachel F. Brem; Jocelyn A. Rapelyea; , Gilat Zisman; Kevin Mohtashemi; Joyce Raub; Christine B. Teal; Stan Majewski; Benjamin L. Welch

    2005-08-01

    To prospectively evaluate a high-resolution breast-specific gamma camera for depicting occult breast cancer in women at high risk for breast cancer but with normal mammographic and physical examination findings. MATERIALS AND METHODS: Institutional Review Board approval and informed consent were obtained. The study was HIPAA compliant. Ninety-four high-risk women (age range, 36-78 years; mean, 55 years) with normal mammographic (Breast Imaging Reporting and Data System [BI-RADS] 1 or 2) and physical examination findings were evaluated with scintimammography. After injection with 25-30 mCi (925-1110 MBq) of technetium 99m sestamibi, patients were imaged with a high-resolution small-field-of-view breast-specific gamma camera in craniocaudal and mediolateral oblique projections. Scintimammograms were prospectively classified according to focal radiotracer uptake as normal (score of 1), with no focal or diffuse uptake; benign (score of 2), with minimal patchy uptake; probably benign (score of 3), with scattered patchy uptake; probably abnormal (score of 4), with mild focal radiotracer uptake; and abnormal (score of 5), with marked focal radiotracer uptake. Mammographic breast density was categorized according to BI-RADS criteria. Patients with normal scintimammograms (scores of 1, 2, or 3) were followed up for 1 year with an annual mammogram, physical examination, and repeat scintimammography. Patients with abnormal scintimammograms (scores of 4 or 5) underwent ultrasonography (US), and those with focal hypoechoic lesions underwent biopsy. If no lesion was found during US, patients were followed up with scintimammography. Specific pathologic findings were compared with scintimammographic findings. RESULTS: Of 94 women, 78 (83%) had normal scintimammograms (score of 1, 2, or 3) at initial examination and 16 (17%) had abnormal scintimammograms (score of 4 or 5). Fourteen (88%) of the 16 patients had either benign findings at biopsy or no focal abnormality at US; in two

  15. Occult Breast Cancer: Scintimammography with High-Resolution Breast-specific Gamma Camera in Women at High Risk for Breast Cancer

    International Nuclear Information System (INIS)

    Rachel F. Brem; Jocelyn A. Rapelyea; , Gilat Zisman; Kevin Mohtashemi; Joyce Raub; Christine B. Teal; Stan Majewski; Benjamin L. Welch

    2005-01-01

    To prospectively evaluate a high-resolution breast-specific gamma camera for depicting occult breast cancer in women at high risk for breast cancer but with normal mammographic and physical examination findings. MATERIALS AND METHODS: Institutional Review Board approval and informed consent were obtained. The study was HIPAA compliant. Ninety-four high-risk women (age range, 36-78 years; mean, 55 years) with normal mammographic (Breast Imaging Reporting and Data System [BI-RADS] 1 or 2) and physical examination findings were evaluated with scintimammography. After injection with 25-30 mCi (925-1110 MBq) of technetium 99m sestamibi, patients were imaged with a high-resolution small-field-of-view breast-specific gamma camera in craniocaudal and mediolateral oblique projections. Scintimammograms were prospectively classified according to focal radiotracer uptake as normal (score of 1), with no focal or diffuse uptake; benign (score of 2), with minimal patchy uptake; probably benign (score of 3), with scattered patchy uptake; probably abnormal (score of 4), with mild focal radiotracer uptake; and abnormal (score of 5), with marked focal radiotracer uptake. Mammographic breast density was categorized according to BI-RADS criteria. Patients with normal scintimammograms (scores of 1, 2, or 3) were followed up for 1 year with an annual mammogram, physical examination, and repeat scintimammography. Patients with abnormal scintimammograms (scores of 4 or 5) underwent ultrasonography (US), and those with focal hypoechoic lesions underwent biopsy. If no lesion was found during US, patients were followed up with scintimammography. Specific pathologic findings were compared with scintimammographic findings. RESULTS: Of 94 women, 78 (83%) had normal scintimammograms (score of 1, 2, or 3) at initial examination and 16 (17%) had abnormal scintimammograms (score of 4 or 5). Fourteen (88%) of the 16 patients had either benign findings at biopsy or no focal abnormality at US; in two

  16. Equipment and applications for gamma spectrometry

    International Nuclear Information System (INIS)

    Hemingway, J.D.

    1986-01-01

    In this article the theoretical aspects of gamma spectroscopy are discussed. Coaxial germanium detectors and planar detectors are described. Applications of gamma spectroscopy to the detection of the exposure of a population to naturally occuring radioactive gases and their daughter products; the accumulation of iodine isotopes in the thyroid and measuring the quantity of 239 Pu in the lungs are discussed. (UK)

  17. Guidelines for radioelement mapping using gamma ray spectrometry data

    International Nuclear Information System (INIS)

    2003-07-01

    The purpose of the report is to provide an up-to-date review on the use of gamma ray spectrometry for radioelement mapping and, where appropriate, provide guidelines on the correct application of the method. It is a useful training guide for those new to the method. It gives a broad coverage of all aspects of the gamma ray method and provides a comprehensive list of references. The report gives an overview of the theoretical background to radioactivity and the gamma ray spectrometric method followed by a review of the application of the method to mapping the radiation environment. A brief outline is presented of the principles of radioactivity, the interaction of gamma rays with matter, instrumentation applied to the measurement of gamma rays, and the quantities and units in contemporary use in gamma ray spectrometry. This is followed by a review of the fundamentals of gamma ray spectrometry, and its application to ground and airborne mapping. Covered are also all aspects of the calibration and data processing procedures required for estimating the ground concentrations of the radioelements. The procedures required for the recovery of older survey data are also presented as well as an overview of data presentation and integration for mapping applications

  18. Correlation of precursor and product ions in single-stage high resolution mass spectrometry. A tool for detecting diagnostic ions and improving the precursor elemental composition elucidation

    Energy Technology Data Exchange (ETDEWEB)

    Borràs, S. [Departament de Química Analítica, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona (Spain); Kaufmann, A., E-mail: anton.kaufmann@klzh.ch [Official Food Control Authority, Fehrenstrasse 15, 8032 Zürich (Switzerland); Companyó, R. [Departament de Química Analítica, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona (Spain)

    2013-04-15

    Highlights: ► We are describing a technique to spot ions which are derived from each other. ► Single stage high resolution data is used. ► This “in silicon” technique is compared to conventional precursor scan. ► Some applications for this technique are presented. -- Abstract: Monitoring of common diagnostic fragments is essential for recognizing molecules which are members of a particular compound class. Up to now, unit resolving tandem quadrupole mass spectrometers, operating in the precursor ion scan mode, have been typically used to perform such analysis. By means of high-resolution mass spectrometry (HRMS) a much more sensitive and selective detection can be achieved. However, using a single-stage HRMS instrument, there is no unequivocal link to the corresponding precursor ion, since such instrumentation does not permit a previous precursor selection. Thus, to address this limitation, an in silico approach to locate precursor ions, based on diagnostic fragments, was developed. Implemented as an Excel macro, the algorithm rapidly assembles and surveys exact mass data to provide a list of feasible precursor candidates according to the correlation of the chromatographic peak shape profile and other additional filtering criteria (e.g. neutral losses and isotopes). The macro was tested with two families of veterinary drugs, sulfonamides and penicillins, which are known to yield diagnostic product ions when fragmented. Data sets obtained from different food matrices (fish and liver), both at high and low concentration of the target compounds, were investigated in order to evaluate the capabilities and limitations of the reported approach. Finally, other possible applications of this technique, such as the elucidation of elemental compositions based on product ions and corresponding neutral losses, were also presented and discussed.

  19. Correlation of precursor and product ions in single-stage high resolution mass spectrometry. A tool for detecting diagnostic ions and improving the precursor elemental composition elucidation

    International Nuclear Information System (INIS)

    Borràs, S.; Kaufmann, A.; Companyó, R.

    2013-01-01

    Highlights: ► We are describing a technique to spot ions which are derived from each other. ► Single stage high resolution data is used. ► This “in silicon” technique is compared to conventional precursor scan. ► Some applications for this technique are presented. -- Abstract: Monitoring of common diagnostic fragments is essential for recognizing molecules which are members of a particular compound class. Up to now, unit resolving tandem quadrupole mass spectrometers, operating in the precursor ion scan mode, have been typically used to perform such analysis. By means of high-resolution mass spectrometry (HRMS) a much more sensitive and selective detection can be achieved. However, using a single-stage HRMS instrument, there is no unequivocal link to the corresponding precursor ion, since such instrumentation does not permit a previous precursor selection. Thus, to address this limitation, an in silico approach to locate precursor ions, based on diagnostic fragments, was developed. Implemented as an Excel macro, the algorithm rapidly assembles and surveys exact mass data to provide a list of feasible precursor candidates according to the correlation of the chromatographic peak shape profile and other additional filtering criteria (e.g. neutral losses and isotopes). The macro was tested with two families of veterinary drugs, sulfonamides and penicillins, which are known to yield diagnostic product ions when fragmented. Data sets obtained from different food matrices (fish and liver), both at high and low concentration of the target compounds, were investigated in order to evaluate the capabilities and limitations of the reported approach. Finally, other possible applications of this technique, such as the elucidation of elemental compositions based on product ions and corresponding neutral losses, were also presented and discussed

  20. Flux Analysis of Free Amino Sugars and Amino Acids in Soils by Isotope Tracing with a Novel Liquid Chromatography/High Resolution Mass Spectrometry Platform.

    Science.gov (United States)

    Hu, Yuntao; Zheng, Qing; Wanek, Wolfgang

    2017-09-05

    Soil fluxomics analysis can provide pivotal information for understanding soil biochemical pathways and their regulation, but direct measurement methods are rare. Here, we describe an approach to measure soil extracellular metabolite (amino sugar and amino acid) concentrations and fluxes based on a 15 N isotope pool dilution technique via liquid chromatography and high-resolution mass spectrometry. We produced commercially unavailable 15 N and 13 C labeled amino sugars and amino acids by hydrolyzing peptidoglycan isolated from isotopically labeled bacterial biomass and used them as tracers ( 15 N) and internal standards ( 13 C). High-resolution (Orbitrap Exactive) MS with a resolution of 50 000 allowed us to separate different stable isotope labeled analogues across a large range of metabolites. The utilization of 13 C internal standards greatly improved the accuracy and reliability of absolute quantification. We successfully applied this method to two types of soils and quantified the extracellular gross fluxes of 2 amino sugars, 18 amino acids, and 4 amino acid enantiomers. Compared to the influx and efflux rates of most amino acids, similar ones were found for glucosamine, indicating that this amino sugar is released through peptidoglycan and chitin decomposition and serves as an important nitrogen source for soil microorganisms. d-Alanine and d-glutamic acid derived from peptidoglycan decomposition exhibited similar turnover rates as their l-enantiomers. This novel approach offers new strategies to advance our understanding of the production and transformation pathways of soil organic N metabolites, including the unknown contributions of peptidoglycan and chitin decomposition to soil organic N cycling.

  1. Organic solvent and temperature-enhanced ion chromatography-high resolution mass spectrometry for the determination of low molecular weight organic and inorganic anions

    International Nuclear Information System (INIS)

    Gilchrist, Elizabeth S.; Nesterenko, Pavel N.; Smith, Norman W.; Barron, Leon P.

    2015-01-01

    Highlights: • IC selectivity at high contents of organic solvent in eluent and elevated temperature is studied. • Solvent-enhanced IC coupled to high resolution MS is beneficial for sensitive detection of ions. • The first application of IC-HRMS to the detection of low explosives in fingermarks is shown. - Abstract: There has recently been increased interest in coupling ion chromatography (IC) to high resolution mass spectrometry (HRMS) to enable highly sensitive and selective analysis. Herein, the first comprehensive study focusing on the direct coupling of suppressed IC to HRMS without the need for post-suppressor organic solvent modification is presented. Chromatographic selectivity and added HRMS sensitivity offered by organic solvent-modified IC eluents on a modern hyper-crosslinked polymeric anion-exchange resin (IonPac AS18) are shown using isocratic eluents containing 5–50 mM hydroxide with 0–80% methanol or acetonitrile for a range of low molecular weight anions (<165 Da). Comprehensive experiments on IC thermodynamics over a temperature range between 20–45 °C with the eluent containing up to 60% of acetonitrile or methanol revealed markedly different retention behaviour and selectivity for the selected analytes on the same polymer based ion-exchange resin. Optimised sensitivity with HRMS was achieved with as low as 30–40% organic eluent content. Analytical performance characteristics are presented and compared with other IC-MS based works. This study also presents the first application of IC-HRMS to forensic detection of trace low-order anionic explosive residues in latent human fingermarks

  2. Organic solvent and temperature-enhanced ion chromatography-high resolution mass spectrometry for the determination of low molecular weight organic and inorganic anions

    Energy Technology Data Exchange (ETDEWEB)

    Gilchrist, Elizabeth S. [Analytical & Environmental Science Division, Department of Forensic & Analytical Science, King’s College London, 150 Stamford Street, London, SE1 9NH (United Kingdom); Nesterenko, Pavel N. [Australian Centre for Research on Separation Science, School of Physical Sciences, University of Tasmania, Private Bag 75, Hobart 7001 (Australia); Smith, Norman W. [Analytical & Environmental Science Division, Department of Forensic & Analytical Science, King’s College London, 150 Stamford Street, London, SE1 9NH (United Kingdom); Barron, Leon P., E-mail: leon.barron@kcl.ac.uk [Analytical & Environmental Science Division, Department of Forensic & Analytical Science, King’s College London, 150 Stamford Street, London, SE1 9NH (United Kingdom)

    2015-03-20

    Highlights: • IC selectivity at high contents of organic solvent in eluent and elevated temperature is studied. • Solvent-enhanced IC coupled to high resolution MS is beneficial for sensitive detection of ions. • The first application of IC-HRMS to the detection of low explosives in fingermarks is shown. - Abstract: There has recently been increased interest in coupling ion chromatography (IC) to high resolution mass spectrometry (HRMS) to enable highly sensitive and selective analysis. Herein, the first comprehensive study focusing on the direct coupling of suppressed IC to HRMS without the need for post-suppressor organic solvent modification is presented. Chromatographic selectivity and added HRMS sensitivity offered by organic solvent-modified IC eluents on a modern hyper-crosslinked polymeric anion-exchange resin (IonPac AS18) are shown using isocratic eluents containing 5–50 mM hydroxide with 0–80% methanol or acetonitrile for a range of low molecular weight anions (<165 Da). Comprehensive experiments on IC thermodynamics over a temperature range between 20–45 °C with the eluent containing up to 60% of acetonitrile or methanol revealed markedly different retention behaviour and selectivity for the selected analytes on the same polymer based ion-exchange resin. Optimised sensitivity with HRMS was achieved with as low as 30–40% organic eluent content. Analytical performance characteristics are presented and compared with other IC-MS based works. This study also presents the first application of IC-HRMS to forensic detection of trace low-order anionic explosive residues in latent human fingermarks.

  3. High-resolution high-sensitivity elemental imaging by secondary ion mass spectrometry: from traditional 2D and 3D imaging to correlative microscopy

    International Nuclear Information System (INIS)

    Wirtz, T; Philipp, P; Audinot, J-N; Dowsett, D; Eswara, S

    2015-01-01

    Secondary ion mass spectrometry (SIMS) constitutes an extremely sensitive technique for imaging surfaces in 2D and 3D. Apart from its excellent sensitivity and high lateral resolution (50 nm on state-of-the-art SIMS instruments), advantages of SIMS include high dynamic range and the ability to differentiate between isotopes. This paper first reviews the underlying principles of SIMS as well as the performance and applications of 2D and 3D SIMS elemental imaging. The prospects for further improving the capabilities of SIMS imaging are discussed. The lateral resolution in SIMS imaging when using the microprobe mode is limited by (i) the ion probe size, which is dependent on the brightness of the primary ion source, the quality of the optics of the primary ion column and the electric fields in the near sample region used to extract secondary ions; (ii) the sensitivity of the analysis as a reasonable secondary ion signal, which must be detected from very tiny voxel sizes and thus from a very limited number of sputtered atoms; and (iii) the physical dimensions of the collision cascade determining the origin of the sputtered ions with respect to the impact site of the incident primary ion probe. One interesting prospect is the use of SIMS-based correlative microscopy. In this approach SIMS is combined with various high-resolution microscopy techniques, so that elemental/chemical information at the highest sensitivity can be obtained with SIMS, while excellent spatial resolution is provided by overlaying the SIMS images with high-resolution images obtained by these microscopy techniques. Examples of this approach are given by presenting in situ combinations of SIMS with transmission electron microscopy (TEM), helium ion microscopy (HIM) and scanning probe microscopy (SPM). (paper)

  4. Metabolic profiling of five flavonoids from Dragon's Blood in human liver microsomes using high-performance liquid chromatography coupled with high resolution mass spectrometry.

    Science.gov (United States)

    Li, Yujuan; Zhang, Yushi; Wang, Rui; Wei, Lizhong; Deng, Yulin; Ren, Wei

    2017-05-01

    Although much is known about the pharmacological activities of Dragon's Blood (DB, a traditional Chinese herb), its metabolism in human liver microsomes (HLMs) and the cytochrome P450 (CYP) enzymes has not been studied. This study aims to identify the metabolic profile of five flavonoids (loureirin A, loureirin B, loureirin C, 7,4'-dihydroxyflavone and 5,7,4'-trihydroxyflavanone) from DB in HLMs as well as the CYP enzymes that are involved in the metabolism of them. High-resolution mass spectrometry was used to characterize the structures of their metabolites and 10 cDNA-expressed CYP enzymes (CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2E1, CYP3A4 and CYP3A5) were used to verify which isozymes mediate in the metabolism of the metabolites. Totally, 29 metabolites including 10 metabolites of loureirin A, 10 metabolites of loureirin B, 4 metabolites of loureirin C, 2 metabolites of 7,4'-dihydroxyflavone and 3 metabolites of 5,7,4'-trihydroxyflavanone were elucidated and identified on the basis of the high-resolution MS n data. The metabolic profile of the five flavonoids in HLMs involved hydroxylation, oxidation and demethylation. Among them, hydroxylation was the predominant biotransformation of the five flavonoids in HLMs, occurring in combination with other metabolic reactions. Assay with recombinant P450s revealed that CYP2C9 and CYP2C19 played an important role in the hydroxylation of flavonoids in HLMs. To the best of our knowledge, this is the first in vitro evaluation of the metabolic profile of loureirin A, loureirin B, loureirin C, 7,4'-dihydroxyflavone and 5,7,4'-trihydroxyflavanone in HLMs. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Flux Analysis of Free Amino Sugars and Amino Acids in Soils by Isotope Tracing with a Novel Liquid Chromatography/High Resolution Mass Spectrometry Platform

    Science.gov (United States)

    2017-01-01

    Soil fluxomics analysis can provide pivotal information for understanding soil biochemical pathways and their regulation, but direct measurement methods are rare. Here, we describe an approach to measure soil extracellular metabolite (amino sugar and amino acid) concentrations and fluxes based on a 15N isotope pool dilution technique via liquid chromatography and high-resolution mass spectrometry. We produced commercially unavailable 15N and 13C labeled amino sugars and amino acids by hydrolyzing peptidoglycan isolated from isotopically labeled bacterial biomass and used them as tracers (15N) and internal standards (13C). High-resolution (Orbitrap Exactive) MS with a resolution of 50 000 allowed us to separate different stable isotope labeled analogues across a large range of metabolites. The utilization of 13C internal standards greatly improved the accuracy and reliability of absolute quantification. We successfully applied this method to two types of soils and quantified the extracellular gross fluxes of 2 amino sugars, 18 amino acids, and 4 amino acid enantiomers. Compared to the influx and efflux rates of most amino acids, similar ones were found for glucosamine, indicating that this amino sugar is released through peptidoglycan and chitin decomposition and serves as an important nitrogen source for soil microorganisms. d-Alanine and d-glutamic acid derived from peptidoglycan decomposition exhibited similar turnover rates as their l-enantiomers. This novel approach offers new strategies to advance our understanding of the production and transformation pathways of soil organic N metabolites, including the unknown contributions of peptidoglycan and chitin decomposition to soil organic N cycling. PMID:28776982

  6. High resolution {sup 12}C({gamma},p) experiments at E{sub {gamma}} {approx_equal} 25-75 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Ruijter, H

    1995-08-01

    Absolute differential cross sections for the {sup 12}C({gamma},p){sup 11}B reaction have been measured over proton detection angels ranging from 30 to 150 deg, using tagged photons of 25-75 MeV energy, for low-lying regions of residual excitation energy in {sup 11}B. Four experiments were performed at the MAX laboratory in Lund in order to provide data. Previously reported cross sections for the reaction had systematic uncertainties of a magnitude which made them agree, in spite of a large spread in absolute values. The cross sections reported, with a systematic uncertainty of 8%, remove previous ambiguities for E{sub {gamma}}=40-75 MeV. A reinterpretation of the states excited in{sup 11}B at E about 7 MeV is also presented. The data are compared with quasi-elastic (e,e`p) results in PWIA in the same recoil momentum range. It is found that the momentum distributions do not scale for the two reaction types. Furthermore, the data are compared with the results for the inverse reaction (p,{gamma}) in the centre-of-momentum system by detailed balance. The comparison with respect to missing momentum indicates an angular dependence in the ({gamma},p) reaction which is not present in the inverse (p,{gamma}) reaction. Recent results from the MAX laboratory for the ({gamma},n) reaction are compared to the ({gamma},p) results. The mirror nuclei {sup 11}C and {sup 11}B have almost identical excitation energy spectra at E{sub {gamma}}=60 MeV. It is concluded that HF-RPA calculations with essential contributions of meson exchange currents provide a qualitative description of the angular distributions obtained for the ({gamma},p) reaction. An extension of the spherical symmetric basis for the wave function is suggested for the states at E about 7 MeV in {sup 11}B. 108 refs, 83 figs.

  7. GammaSem Proceedings. A Nordic seminar for users of gamma spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Straalberg, E. (ed.) (Institute for Energy Technolgy (Norway)); Berg, K. (National Institute of Radiation Protection (Denmark)); Dowdall, M. (Norwegian Radiation Protection Authority (Norway)) (and others)

    2010-11-15

    The project GammaSem was proposed to the NKS in 2008. The aim of the project was to arrange two seminars for users of gamma spectrometry, in 2009 and 2010. The seminars were meant to provide a forum for discussions and sharing of information on practical issues concerning gamma spectrometry and initiate a network of gamma spectrometry users in the Nordic countries. Such a Nordic network should strengthen the collaboration between laboratories and improve all participants' competence in practical gamma spectrometry. Both seminars' focus was practical challenges met by the users themselves, rather than theoretical matters. Scientists and users of gamma spectrometry from all five Nordic countries were invited to the seminar, as well as scientist from the Baltic countries. A total of 65 people signed up for GammaSem 2010; representing 30 different universities, commercial companies, research institutes and authorities. The working group concept as presented at last year's GammaSem, has not worked out as intended. The reason for this is probably because most of the laboratories that signed up to join the working groups, signed up because they wanted to learn more about the different subjects. In combination with the fact that no funding was made available for the working groups, it was difficult to establish goals on what to achieve. None of the working groups applied for funding from the NKS (or elsewhere) to establish separate projects. There is a big need for more cooperation and for training within the field of gamma spectrometry. This fact has been proved through these two seminars, both by the many different topics that have been discussed, but also by the huge interest for participating in the suggested series of workshop. The GammaSem seminars have thus provided a much welcomed starting point for a broader Nordic collaboration. (Author)

  8. GammaSem Proceedings. A Nordic seminar for users of gamma spectrometry

    International Nuclear Information System (INIS)

    Straelberg, E.; Berg, K.; Dowdall, M.

    2010-11-01

    The project GammaSem was proposed to the NKS in 2008. The aim of the project was to arrange two seminars for users of gamma spectrometry, in 2009 and 2010. The seminars were meant to provide a forum for discussions and sharing of information on practical issues concerning gamma spectrometry and initiate a network of gamma spectrometry users in the Nordic countries. Such a Nordic network should strengthen the collaboration between laboratories and improve all participants' competence in practical gamma spectrometry. Both seminars' focus was practical challenges met by the users themselves, rather than theoretical matters. Scientists and users of gamma spectrometry from all five Nordic countries were invited to the seminar, as well as scientist from the Baltic countries. A total of 65 people signed up for GammaSem 2010; representing 30 different universities, commercial companies, research institutes and authorities. The working group concept as presented at last year's GammaSem, has not worked out as intended. The reason for this is probably because most of the laboratories that signed up to join the working groups, signed up because they wanted to learn more about the different subjects. In combination with the fact that no funding was made available for the working groups, it was difficult to establish goals on what to achieve. None of the working groups applied for funding from the NKS (or elsewhere) to establish separate projects. There is a big need for more cooperation and for training within the field of gamma spectrometry. This fact has been proved through these two seminars, both by the many different topics that have been discussed, but also by the huge interest for participating in the suggested series of workshop. The GammaSem seminars have thus provided a much welcomed starting point for a broader Nordic collaboration. (Author)

  9. Detector calibration for in-situ gamma ray spectrometry

    CERN Document Server

    Balea, G

    2002-01-01

    The power in the technique of in-situ spectrometry lies in the fact that a detector placed on ground measures gamma radiation from sources situated over an area of several hundred square meters. The 'field of view' for the detector would be larger for high energy radiation sources and for sources closer to the soil surface. In contrast, a soil sample would represent an area of a few tens of hundreds of square centimeters. In practice, an effective characterization of a site would involve in-situ gamma ray spectrometry in conjunction with soil sampling. As part of an overall program, in-situ gamma ray spectrometry provides a means to assess the degree of contamination in areas during the course of operations in the field, thus guiding the investigator on where to collect samples. It can also substantially reduce the number of samples need to be collected and subsequently analyzed. (author)

  10. Gamma spectrometry on MANITU 271-01 gamma scan wires

    International Nuclear Information System (INIS)

    Dassel, G.; Buurveld, H.A.; Minkema, J.

    1994-08-01

    A series of irradiation experiments (271-series) is being performed of the sustain programme for material development and characterization of the NET (Next European Torus). In the framework of the first irradiation experiment 271-01, with irradiation up to 0.2 dpa, four gamma scan wires have been examined by gamma scanning. The purpose of the gamma scan wires (GSW) is to get information about the neutron fluence distribution in the capsules during irradiation. In the stainless steel wires the nuclides Co-58, Mu-54, Fe-59 and Co-60 are produced, are characteristic for fast and thermal neutron reactions. (orig./HP)

  11. Chlorinated paraffin analysis by gas chromatography Orbitrap high-resolution mass spectrometry: Method performance, investigation of possible interferences and analysis of fish samples.

    Science.gov (United States)

    Krätschmer, Kerstin; Cojocariu, Cristian; Schächtele, Alexander; Malisch, Rainer; Vetter, Walter

    2018-03-02

    For decades, high quantities of short-chain chlorinated paraffins (SCCP) and medium-chain chlorinated paraffins (MCCP) have been widely used, for instance as plasticizers or flame retardants, leading to global pollution due to unintentional emissions from products or waste. Due to the high complexity of chlorinated paraffins with several thousand congeners there is no consensus on an analytical procedure for SCCPs and MCCPs in food samples. Amongst the multitude of methods currently in use, high-resolution mass spectrometry is particularly valuable for in-depth studies of homologue patterns. Here we analyse SCCPs and MCCPs with gas chromatography coupled to high-resolution Orbitrap mass spectrometry (GC-Orbitrap-HRMS) operated in full-scan acquisition in electron capture negative ion (ECNI) mode at 60,000 and 120,000 resolution (FWHM, m/z 200, equals roughly 30,000 and 60,000 at 5% peak height). Linear dynamic range, selectivity and sensitivity tests confirmed an excellent linearity in a concentration range of 25-15,000 pg/μL with very low limits of detection (LODs) in the low pg/μL range. Spiking experiments with high levels of native mono- and di-ortho-polychlorinated biphenyls (PCBs) and mixtures of MCCP and SCCP standards did not have a negative impact on isotope ratios of the examined homologues. Besides the [M-Cl] - fragment ions used for quantification, the mass spectra of homologues also featured [M-HCl] - ions whose abundance increased with decreasing chlorination degree. In addition, [M-HCl-Cl] - ions were detected with a relative abundance of 5-10%. Three salmon (Salmo salar) samples farmed in Norway showed a consistent CP homologue pattern which differed both from the CP pattern in a sample from Scottish aquaculture and a wild salmon sample. These measurements produce evidence that discretely different CP patterns may exist in different areas of origin. Our results demonstrate that GC/ECNI-Orbitrap-HRMS is well-suited for the analysis of CPs by

  12. Characterization of aromatic organosulfur model compounds relevant to fossil fuels by using atmospheric pressure chemical ionization with CS2 and high-resolution tandem mass spectrometry.

    Science.gov (United States)

    Tang, Weijuan; Sheng, Huaming; Jin, Chunfen; Riedeman, James S; Kenttämaa, Hilkka I

    2016-04-15

    The chemistry of desulfurization involved in processing crude oil is greatly dependent on the forms of sulfur in the oil. Sulfur exists in different chemical bonding environments in fossil fuels, including those in thiophenes and benzothiophenes, thiols, sulfides, and disulfides. In this study, the fragmentation behavior of the molecular ions of 17 aromatic organosulfur compounds with various functionalities was systematically investigated by using high-resolution tandem mass spectrometry. Multiple-stage tandem mass spectrometric experiments were carried out using a linear quadrupole ion trap (LQIT) equipped with an atmospheric pressure chemical ionization (APCI) source. (+)APCI/CS2 was used to generate stable dominant molecular ions for all the compounds studied except for three sulfides that also showed abundant fragment ions. The LQIT coupled with an orbitrap mass spectrometer was used for elemental composition analysis, which facilitated the identification of the neutral molecules lost during fragmentation. The characteristic fragment ions generated in MS(2) and MS(3) experiments provide clues for the chemical bonding environment of sulfur atoms in the examined compounds. Upon collision-induced dissociation (CID), the molecular ions can lose the sulfur atom in a variety of ways, including as S (32 Da), HS(•) (33 Da), H2 S (34 Da), CS (44 Da), (•) CHS (45 Da) and CH2 S (46 Da). These neutral fragments are not only indicative of the presence of sulfur, but also of the type of sulfur present in the compound. Generally, losses of HS(•) and H2 S were found to be associated with compounds containing saturated sulfur functionalities, while losses of S, CS and (•) CHS were more common for heteroaromatic sulfur compounds. High-resolution tandem mass spectrometry with APCI/CS2 ionization is a viable approach to determining the types of organosulfur compounds. It can potentially be applied to analysis of complex mixtures, which is beneficial to improving the

  13. On response operator in semiconductor gamma ray spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Krnac, S [Slovak Technical Univ., Bratislava (Slovakia); Povinec, P [International Atomic Energy Agency, Monaco (Monaco). MEL; Ragan, R [Inst. of Preventive and Clinical Medicine, Bratislava (Slovakia)

    1996-12-31

    Some results of the scaling confirmation factor analysis (SCFA) application in semiconductor gamma-ray spectrometry presented in this contribution points out to a new ground for evaluation the gamma-ray spectra. This whole-spectrum processing approach considerably increases detection sensitivity, especially, if significant interferences being present in the measured spectrum. Precision of the SCFA method is determined by choice of a sufficient number of suitable calibration gamma-ray sources in the energy region of interest, by setting up an acceptable latent hypothesis and by chosen experimental quantification of spectra. The SCFA method is very advantageous to use, for instance, in ultra low-level gamma-spectrometry where counting rates in full energy peaks are extremely low as compared with background interferences. It enables to increase of the sensitivity by the 5-10 times in comparison with the traditional full energy peak net area method (J.K.). 1 fig., 2 tabs., 6 refs.

  14. On response operator in semiconductor gamma ray spectrometry

    International Nuclear Information System (INIS)

    Krnac, S.; Povinec, P.

    1995-01-01

    Some results of the scaling confirmation factor analysis (SCFA) application in semiconductor gamma-ray spectrometry presented in this contribution points out to a new ground for evaluation the gamma-ray spectra. This whole-spectrum processing approach considerably increases detection sensitivity, especially, if significant interferences being present in the measured spectrum. Precision of the SCFA method is determined by choice of a sufficient number of suitable calibration gamma-ray sources in the energy region of interest, by setting up an acceptable latent hypothesis and by chosen experimental quantification of spectra. The SCFA method is very advantageous to use, for instance, in ultra low-level gamma-spectrometry where counting rates in full energy peaks are extremely low as compared with background interferences. It enables to increase of the sensitivity by the 5-10 times in comparison with the traditional full energy peak net area method (J.K.). 1 fig., 2 tabs., 6 refs

  15. The Utilization of Background Spectrum to Calibrate Gamma Spectrometry

    International Nuclear Information System (INIS)

    Mahrouka, M. M.; Mutawa, A. M.

    2004-01-01

    Many developed countries have very poor reference standards to calibrate their nuclear instrumentations or may find some difficulties to obtain a reference standard. In this work a simple way for Gamma spectrometry calibration was developed. The method depends on one reference point and additional points from the background. The two derived equations were applied to the analyses of radioactive nuclides in soil and liquid samples prepared by IAEA laboratories through AL MERA Project. The results showed the precision of the methodology used, as well as, the possibility of using some points in the background spectrum as a replacement for reference standards of Gamma spectrometry calibration. (authors)

  16. Methodology for determination of activity of radionuclides by gamma spectrometry

    International Nuclear Information System (INIS)

    Fragoso, Maria da Conceicao de Farias; Oliveira, Victor Rogerio S. de; Oliveira, Mercia L.; Lima, Fernando Roberto de Andrade

    2014-01-01

    Due to the growth in the number of procedures that make use of the positron emission tomography (PET), there is a need for standard solutions for the calibration of the systems used for the measurement of the PET radiopharmaceutical (activimeter) in radiopharmacies and in nuclear medicine services. Among the existing alternatives for the standardization of radioactive sources, the method known as gamma spectrometry is widely used for short-lived radionuclides. The purpose of this study was to implement the methodology for standardization of the 18 F solutions by gamma spectrometry at the Regional Center for Nuclear Sciences of the Northeast (CRCN-NE/CNEN-NE), Brazil. (author)

  17. Gamma spectrometry of 285-04 ILAS gamma scan wires

    International Nuclear Information System (INIS)

    Dassel, G.; Buurveld, H.A.; Plakman, J.C.

    1996-12-01

    In the frame work of their on-going sustain programme for the material development and characterization of fusion reactors, ECN is investigating the irradiation behaviour of ferritic/martensitic steels. In the fourth irradiation experiment 285-04, 55 steel tensile samples have been irradiated up to 2.5 dpa. Four gamma scan wires from this experiment have been examined by gamma scanning. The results of the measurements have been described in this report. (orig.)

  18. Gamma spectrometry of 285-03 ILAS gamma scan wires

    International Nuclear Information System (INIS)

    Dassel, G.; Buurveld, H.A.; Plakman, J.C.

    1996-12-01

    In the frame work of their on-going sustain programme for the material development and characterization of fusion reactors, ECN is investigating the irradiation behaviour of ferritic/martensitic steels. In the third irradiation experiment 285-03, 55 vanadium (V-4Cr-4Ti) tensile samples have been irradiated up to 6 dpa. Four gamma scan wires from this experiment have been examined by gamma scanning. The results of the measurements have been described in this report. (orig.)

  19. Solid state scintillators for gamma spectrometry

    International Nuclear Information System (INIS)

    La Mela, G.; Torrisi, M.

    1991-01-01

    Using different scintillator crystals, measurements of energy resolution and detection efficiency have been performed to detect gamma rays of energy ranging between 500 en 1550 KeV. This investigation is devoted to characterize the best systems to detect photons coming from positron annihilation processes, such as a PET apparatus where the medical image is the final aim of the investigation, and gamma emission from radioisotopes of biomedical interest

  20. Quantitative Isotope-Dilution High-Resolution-Mass-Spectrometry Analysis of Multiple Intracellular Metabolites in Clostridium autoethanogenum with Uniformly 13C-Labeled Standards Derived from Spirulina.

    Science.gov (United States)

    Schatschneider, Sarah; Abdelrazig, Salah; Safo, Laudina; Henstra, Anne M; Millat, Thomas; Kim, Dong-Hyun; Winzer, Klaus; Minton, Nigel P; Barrett, David A

    2018-04-03

    We have investigated the applicability of commercially available lyophilized spirulina ( Arthrospira platensis), a microorganism uniformly labeled with 13 C, as a readily accessible source of multiple 13 C-labeled metabolites suitable as internal standards for the quantitative determination of intracellular bacterial metabolites. Metabolites of interest were analyzed by hydrophilic-interaction liquid chromatography coupled with high-resolution mass spectrometry. Multiple internal standards obtained from uniformly (U)- 13 C-labeled extracts from spirulina were used to enable isotope-dilution mass spectrometry (IDMS) in the identification and quantification of intracellular metabolites. Extraction of the intracellular metabolites of Clostridium autoethanogenum using 2:1:1 chloroform/methanol/water was found to be the optimal method in comparison with freeze-thaw, homogenization, and sonication methods. The limits of quantification were ≤1 μM with excellent linearity for all of the calibration curves ( R 2 ≥ 0.99) for 74 metabolites. The precision and accuracy were found to be within relative standard deviations (RSDs) of 15% for 49 of the metabolites and within RSDs of 20% for all of the metabolites. The method was applied to study the effects of feeding different levels of carbon monoxide (as a carbon source) on the central metabolism and Wood-Ljungdahl pathway of C. autoethanogenum grown in continuous culture over 35 days. Using LC-IDMS with U- 13 C spirulina allowed the successful quantification of 52 metabolites in the samples, including amino acids, carboxylic acids, sugar phosphates, purines, and pyrimidines. The method provided absolute quantitative data on intracellular metabolites that was suitable for computational modeling to understand and optimize the C. autoethanogenum metabolic pathways active in gas fermentation.

  1. A simple and fast method for assessment of the nitrogen–phosphorus–potassium rating of fertilizers using high-resolution continuum source atomic and molecular absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Bechlin, Marcos André; Fortunato, Felipe Manfroi; Moutinho da Silva, Ricardo; Ferreira, Edilene Cristina; Gomes Neto, José Anchieta, E-mail: anchieta@iq.unesp.br

    2014-11-01

    The determination of N, P, and K in fertilizers by high-resolution continuum source flame atomic and molecular absorption spectrometry is proposed. Under optimized conditions, measurements of the diatomic molecules NO and PO at 215.360 and 247.620 nm, respectively, and K using the wing of the alternative line at 404.722 nm allowed calibration curves to be constructed in the ranges 500–5000 mg L{sup −1} N (r = 0.9994), 100–2000 mg L{sup −1} P (r = 0.9946), and 100–2500 mg L{sup −1} K (r = 0.9995). Commercial fertilizers were analyzed by the proposed method and the concentrations of N, P, and K were found to be in agreement with those obtained by Kjeldahl, spectrophotometric, and flame atomic emission spectrometry methods, respectively, at a 95% confidence level (paired t-test). A phosphate rock certified reference material (CRM) was analyzed and the results for P and K were in agreement with the reference values. Recoveries from spiked CRM were in the ranges 97–105% (NO{sub 3}{sup −}-N), 95–103% (NH{sub 4}{sup +}-N), 93–103% (urea-N), 99–108% (P), and 99–102% (K). The relative standard deviations (n = 12) for N, P, and K were 6, 4, and 2%, respectively. - Highlights: • A single technique is proposed to analyze NPK fertilizer. • HR-CS FAAS is proposed for the first time for N, P and K determination in fertilizers. • The method employs the same sample preparation and dilution for the three analytes. • Addition of H{sub 2}O{sub 2} allows analysis of fertilizers with different nitrogen species. • Proposal provides advantages over traditional methods in terms of cost and time.

  2. CHARACTERIZATION OF ENALAPRIL AND RANITIDINE CHLORINATION BY-PRODUCTS BY LIQUID CHROMATOGRAPHY/HIGH-RESOLUTION MASS SPECTROMETRY AND THEIR TOXICITY EVALUATION

    Directory of Open Access Journals (Sweden)

    Frederico Jehár Oliveira Quintão

    Full Text Available Due to its low cost, its capability for disinfection and oxidation, chlorination using gaseous chlorine or hypochlorite salts, has also been commonly applied in water treatment plants for oxidation and disinfection purposes. Little is known about the identity and toxicity of by-products resulting from the chlorination of pharmaceutical micropollutants, such as enalapril (ENA and ranitidine (RAN. ENA and RAN chlorination by-products were characterized in this study by high-performance liquid chromatography coupled to high-resolution mass spectrometry (HPLC/HRMS and their toxicity were assessed by MTT assay. Chlorination experiments with ENA and RAN solutions (10 mg L-1 indicate degradation efficiencies of 100% for both compounds after only 5 min of exposure to chlorine at concentration of 9.53 mg Cl2 L-1. On the other hand mineralization rates were lower than 3%, thereby indicating there was accumulation of degradation by-products in all experiments. Mass spectrometric analysis revealed, at all times of reaction after the addition of hypochlorite, the presence of 1-(2-((4-(chlorophenyl-1-ethoxy-1-oxobutan-2-ylaminopropanoylpyrrolidine-2-carboxylic acid (enalapril by-product and N-chloro-N-(2-(((chloro-5-((dimethylaminomethylfuran-2-ylmethylsulfinylethyl-N-methyl-2-nitroethene 1,1-diamine (ranitidine by-product. Despite the formation of oxidized chlorinated by-products in all chlorination assays, the treated solutions were nontoxic to HepG2 cells by the MTT assay. It has been observed that chlorination (10 mg L-1, 5 min of ENA and RAN solutions exhibited high degradation efficiencies of the target compounds and low mineralization rates. Based on the mass spectrometry data, the routes for ENA and RAN successive oxidation by chlorine has been proposed.

  3. A simple and fast method for assessment of the nitrogen–phosphorus–potassium rating of fertilizers using high-resolution continuum source atomic and molecular absorption spectrometry

    International Nuclear Information System (INIS)

    Bechlin, Marcos André; Fortunato, Felipe Manfroi; Moutinho da Silva, Ricardo; Ferreira, Edilene Cristina; Gomes Neto, José Anchieta

    2014-01-01

    The determination of N, P, and K in fertilizers by high-resolution continuum source flame atomic and molecular absorption spectrometry is proposed. Under optimized conditions, measurements of the diatomic molecules NO and PO at 215.360 and 247.620 nm, respectively, and K using the wing of the alternative line at 404.722 nm allowed calibration curves to be constructed in the ranges 500–5000 mg L −1 N (r = 0.9994), 100–2000 mg L −1 P (r = 0.9946), and 100–2500 mg L −1 K (r = 0.9995). Commercial fertilizers were analyzed by the proposed method and the concentrations of N, P, and K were found to be in agreement with those obtained by Kjeldahl, spectrophotometric, and flame atomic emission spectrometry methods, respectively, at a 95% confidence level (paired t-test). A phosphate rock certified reference material (CRM) was analyzed and the results for P and K were in agreement with the reference values. Recoveries from spiked CRM were in the ranges 97–105% (NO 3 − -N), 95–103% (NH 4 + -N), 93–103% (urea-N), 99–108% (P), and 99–102% (K). The relative standard deviations (n = 12) for N, P, and K were 6, 4, and 2%, respectively. - Highlights: • A single technique is proposed to analyze NPK fertilizer. • HR-CS FAAS is proposed for the first time for N, P and K determination in fertilizers. • The method employs the same sample preparation and dilution for the three analytes. • Addition of H 2 O 2 allows analysis of fertilizers with different nitrogen species. • Proposal provides advantages over traditional methods in terms of cost and time

  4. Ultra-high performance supercritical fluid chromatography hyphenated to atmospheric pressure chemical ionization high resolution mass spectrometry for the characterization of fast pyrolysis bio-oils.

    Science.gov (United States)

    Crepier, Julien; Le Masle, Agnès; Charon, Nadège; Albrieux, Florian; Duchene, Pascal; Heinisch, Sabine

    2018-06-01

    Extensive characterization of complex mixtures requires the combination of powerful analytical techniques. A Supercritical Fluid Chromatography (SFC) method was previously developed, for the specific case of fast pyrolysis bio oils, as an alternative to gas chromatography (GC and GC × GC) or liquid chromatography (LC and LC × LC), both separation methods being generally used prior to mass spectrometry (MS) for the characterization of such complex matrices. In this study we investigated the potential of SFC hyphenated to high resolution mass spectrometry (SFC-HRMS) for this characterization using Negative ion Atmospheric Pressure Chemical ionization ((-)APCI) for the ionization source. The interface between SFC and (-)APCI/HRMS was optimized from a mix of model compounds with the objective of maximizing the signal to noise ratio. The main studied parameters included both make-up flow-rate and make-up composition. A methodology for the treatment of APCI/HRMS data is proposed. This latter allowed for the identification of molecular formulae. Both SFC-APCI/HRMS method and data processing method were applied to a mixture of 36 model compounds, first analyzed alone and then spiked in a bio-oil. In both cases, 19 compounds could be detected. Among them 9 could be detected in a fast pyrolysis bio-oil by targeted analysis. The whole procedure was applied to the characterization of a bio-oil using helpful representations such as mass-plots, van Krevelen diagrams and heteroatom class distributions. Finally the results were compared with those obtained with a Fourier Transform ion-cyclotron resonance mass spectrometer (FT-ICR/MS). Copyright © 2018 Elsevier B.V. All rights reserved.

  5. GammaSem Proceedings - A Nordic seminar for users of gamma spectrometry

    International Nuclear Information System (INIS)

    Nunez, P.; Klemola, S.; Nielsen, Sven P.; Palsson, S.E.; Israelson, C.

    2010-03-01

    The project GammaSem was proposed to provide a forum for discussions and sharing of information on practical issues concerning gamma spectrometry and to establish a network of users of gamma spectrometry in the Nordic countries, thereby strengthening the collaboration and improving all participants' competence in practical gamma spectrometry. The seminars' focus was practical challenges met by the users themselves, rather than theoretical matters. Scientists and users of gamma spectrometry from all five Nordic countries were invited to the seminar, as well as scientist from the Baltic countries. A total of 75 people participated; representing 34 different universities, commercial companies, research institutes and also all Nordic authorities. During the seminar several key issues for follow-up were identified and working groups for addressing the identified problems were established. The working groups were: 1) Uncertainties and detections of limits 2) True summing coincidence 3) Monte Carlo simulations and efficiency transfer 4) Absorption (density corrections and geometries) 5) Mobile gamma spectrometry systems 6) Nuclear forensics (on special samples and special parts of the spectra). The identified topics will form the basis for the agenda of the next seminar in 2010. There, the different working groups will be invited to present their ideas/solutions to the relevant problems. (author)

  6. GammaSem Proceedings - A Nordic seminar for users of gamma spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Nunez, P. (ed.) (Institute for Energy Technology (IFE) (Norway)); Klemola, S. (Radiation and Nuclear Safety Authority (STUK) (Finland)); Nielsen, Sven P. (Technical Univ. of Denmark, Risoe National Lab. for Sustainable Energy. Roskilde (Denmark)); Palsson, S.E. (Icelandic Radiation Safety Authority (IS)); Israelson, C. (National Institute of Radiation Protection (Denmark))

    2010-03-15

    The project GammaSem was proposed to provide a forum for discussions and sharing of information on practical issues concerning gamma spectrometry and to establish a network of users of gamma spectrometry in the Nordic countries, thereby strengthening the collaboration and improving all participants' competence in practical gamma spectrometry. The seminars' focus was practical challenges met by the users themselves, rather than theoretical matters. Scientists and users of gamma spectrometry from all five Nordic countries were invited to the seminar, as well as scientist from the Baltic countries. A total of 75 people participated; representing 34 different universities, commercial companies, research institutes and also all Nordic authorities. During the seminar several key issues for follow-up were identified and working groups for addressing the identified problems were established. The working groups were: 1) Uncertainties and detections of limits 2) True summing coincidence 3) Monte Carlo simulations and efficiency transfer 4) Absorption (density corrections and geometries) 5) Mobile gamma spectrometry systems 6) Nuclear forensics (on special samples and special parts of the spectra). The identified topics will form the basis for the agenda of the next seminar in 2010. There, the different working groups will be invited to present their ideas/solutions to the relevant problems. (author)

  7. High-resolution continuum source atomic absorption spectrometry for the simultaneous or sequential monitoring of multiple lines. A critical review of current possibilities

    International Nuclear Information System (INIS)

    Resano, M.; Flórez, M.R.; García-Ruiz, E.

    2013-01-01

    This work examines the capabilities and limitations of commercially available high-resolution continuum source atomic absorption spectrometry instrumentation for multi-line monitoring, discussing in detail the possible strategies to develop multi-element methodologies that are truly simultaneous, or else sequential, but from the same sample aliquot. Moreover, the simultaneous monitoring of various atomic or molecular lines may bring other important analytical advantages, such as: i) expansion of the linear range by monitoring multiplets; ii) improvements in the limit of detection and in precision by summing the signals from different lines of the same element or molecule; iii) simple correction for matrix-effects by selecting a suitable internal standard; or iv) accurate mathematical correction of spectral overlaps by simultaneous monitoring of free lines of the interfering molecule or element. This work discusses how authors have made use of these strategies to develop analytical methodologies that permit the straightforward analysis of complex samples. - Highlights: • HR CS AAS potential for simultaneous multi-line monitoring is critically examined. • Strategies to develop simultaneous multi-element methods are discussed. • Other benefits of multi-line monitoring (e.g., use of an IS or LSBC) are highlighted. • Selected examples from the literature are discussed in detail

  8. A Method for Simultaneous Determination of 20 Fusarium Toxins in Cereals by High-Resolution Liquid Chromatography-Orbitrap Mass Spectrometry with a Pentafluorophenyl Column

    Science.gov (United States)

    Tamura, Masayoshi; Mochizuki, Naoki; Nagatomi, Yasushi; Harayama, Koichi; Toriba, Akira; Hayakawa, Kazuichi

    2015-01-01

    A high-resolution liquid chromatography-Orbitrap mass spectrometry (LC-Orbitrap MS) method was developed for simultaneous determination of 20 Fusarium toxins (nivalenol, fusarenon-X, deoxynivalenol, 3-acetyl deoxynivalenol, 15-acetyl deoxynivalenol, HT-2 toxin, T-2 toxin, neosolaniol, diacetoxyscirpenol, fumonisin B1, fumonisin B2, fumonisin B3, fumonisin A1, fumonisin A2, fumonisin A3, zearalenone, α-zearalenol, β-zearalenol, α-zearalanol, and β-zearalanol) in cereals. The separation of 20 Fusarium toxins with good peak shapes was achieved using a pentafluorophenyl column, and Orbitrap MS was able to detect accurately from cereal matrix components within ±0.77 ppm. The samples were prepared using a QuEChERS kit for extraction and a multifunctional cartridge for purification. The linearity, repeatability, and recovery of the method were >0.9964, 0.8%–14.7%, and 71%–106%, respectively. Using this method, an analysis of 34 commercially available cereals detected the presence of deoxynivalenol, 15-acetyl deoxynivalenol, fumonisin B1, fumonisin B2, fumonisin B3, fumonisn A1, fumonisin A2, fumonisin A3, and zearalenone in corn samples with high concentration and frequency. Trichothecenes was detected from wheat samples with high frequency; in particular, the concentration of deoxynivalenol was high. Conversely, α-zearalenol, β-zearalenol, α-zearalanol, and β-zearalanol were not detected in any of the samples. PMID:26008230

  9. In house validation of a high resolution mass spectrometry Orbitrap-based method for multiple allergen detection in a processed model food.

    Science.gov (United States)

    Pilolli, Rosa; De Angelis, Elisabetta; Monaci, Linda

    2018-02-13

    In recent years, mass spectrometry (MS) has been establishing its role in the development of analytical methods for multiple allergen detection, but most analyses are being carried out on low-resolution mass spectrometers such as triple quadrupole or ion traps. In this investigation, performance provided by a high resolution (HR) hybrid quadrupole-Orbitrap™ MS platform for the multiple allergens detection in processed food matrix is presented. In particular, three different acquisition modes were compared: full-MS, targeted-selected ion monitoring with data-dependent fragmentation (t-SIM/dd2), and parallel reaction monitoring. In order to challenge the HR-MS platform, the sample preparation was kept as simple as possible, limited to a 30-min ultrasound-aided protein extraction followed by clean-up with disposable size exclusion cartridges. Selected peptide markers tracing for five allergenic ingredients namely skim milk, whole egg, soy flour, ground hazelnut, and ground peanut were monitored in home-made cookies chosen as model processed matrix. Timed t-SIM/dd2 was found the best choice as a good compromise between sensitivity and accuracy, accomplishing the detection of 17 peptides originating from the five allergens in the same run. The optimized method was validated in-house through the evaluation of matrix and processing effects, recoveries, and precision. The selected quantitative markers for each allergenic ingredient provided quantification of 60-100 μg ingred /g allergenic ingredient/matrix in incurred cookies.

  10. Determination of phospholipids in soybean lecithin samples via the phosphorus monoxide molecule by high-resolution continuum source graphite furnace molecular absorption spectrometry.

    Science.gov (United States)

    Pires, Laís N; Brandão, Geovani C; Teixeira, Leonardo S G

    2017-06-15

    This paper presents a method for determining phospholipids in soybean lecithin samples by phosphorus determination using high-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS GF MAS) via molecular absorption of phosphorus monoxide. Samples were diluted in methyl isobutyl ketone. The best conditions were found to be 213.561nm with a pyrolysis temperature of 1300°C, a volatilization temperature of 2300°C and Mg as a chemical modifier. To increase the analytical sensitivity, measurement of the absorbance signal was obtained by summing molecular transition lines for PO surrounding 213nm: 213.561, 213.526, 213.617 and 213.637nm. The limit of detection was 2.35mgg -1 and the precision, evaluated as relative standard deviation (RSD), was 2.47% (n=10) for a sample containing 2.2% (w/v) phosphorus. The developed method was applied for the analysis of commercial samples of soybean lecithin. The determined concentrations of phospholipids in the samples varied between 38.1 and 45% (w/v). Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Use of slurry sampling for the direct determination of zinc in yogurt by high resolution-continuum source flame atomic absorption spectrometry.

    Science.gov (United States)

    Brandao, Geovani C; de Jesus, Raildo M; da Silva, Erik G P; Ferreira, Sergio L C

    2010-06-15

    This paper presents an analytical procedure for the direct determination of zinc in yogurt employing sampling slurry and high resolution-continuum source flame atomic absorption spectrometry (HR-CS FAAS). The step optimization established the experimental conditions of: 2.0molL(-1) hydrochloric acid, a sonication time of 20min and a sample mass of 1.0g for a slurry volume of 25mL. This method allows the determination of zinc with a limit of quantification of 0.32microgg(-1). The precision expressed as relative standard deviation (RSD) were 0.82 and 2.08% for yogurt samples containing zinc concentrations of 4.85 and 2.49microgg(-1), respectively. The accuracy was confirmed by the analysis of a certified reference material of non-fat milk powder furnished by the National Institute of Standard and Technology. The proposed method was applied for the determination of zinc in seven yogurt samples. The zinc content was varied from 2.19 to 4.85microgg(-1). These results agreed with those reported in the literature. The samples were also analyzed after acid digestion and zinc determination by FAAS. No statistical difference was observed between the results obtained by both of the procedures performed.

  12. Identification of urinary biomarkers of exposure to di-(2-propylheptyl) phthalate using high-resolution mass spectrometry and two data-screening approaches.

    Science.gov (United States)

    Shih, Chia-Lung; Liao, Pao-Mei; Hsu, Jen-Yi; Chung, Yi-Ning; Zgoda, Victor G; Liao, Pao-Chi

    2018-02-01

    Di-(2-propylheptyl) phthalate (DPHP) is a plasticizer used in polyvinyl chloride and vinyl chloride copolymer that has been suggested to be a toxicant in rats and may affect human health. Because the use of DPHP is increasing, the general German population is being exposed to DPHP. Toxicant metabolism is important for human toxicant exposure assessments. To date, the knowledge regarding DPHP metabolism has been limited, and only four metabolites have been identified in human urine. Ultra-performance liquid chromatography was coupled with Orbitrap high-resolution mass spectrometry (MS) and two data-screening approaches-the signal mining algorithm with isotope tracing (SMAIT) and the mass defect filter (MDF)-for DPHP metabolite candidate discovery. In total, 13 and 104 metabolite candidates were identified by the two approaches, respectively, in in vitro DPHP incubation samples. Of these candidates, 17 were validated as tentative exposure biomarkers using a rat model, 13 of which have not been reported in the literature. The two approaches generated rather different tentative DPHP exposure biomarkers, indicating that these approaches are complementary for discovering exposure biomarkers. Compared with the four previously reported DPHP metabolites, the three tentative novel biomarkers had higher peak intensity ratios, and two were confirmed as DPHP hydroxyl metabolites based on their MS/MS product ion profiles. These three tentative novel biomarkers should be further investigated for potential application in human exposure assessment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Metabolites of 5F-AKB-48, a synthetic cannabinoid receptor agonist, identified in human urine and liver microsomal preparations using liquid chromatography high-resolution mass spectrometry.

    Science.gov (United States)

    Holm, Niels Bjerre; Pedersen, Anders Just; Dalsgaard, Petur Weihe; Linnet, Kristian

    2015-03-01

    New types of synthetic cannabinoid designer drugs are constantly introduced to the illicit drug market to circumvent legislation. Recently, N-​(1-Adamant​yl)-​1-​(5-​fluoropentyl)-​1H-​indazole-​3-​carboxamide (5F-AKB-48), also known as 5F-APINACA, was identified as an adulterant in herbal products. This compound deviates from earlier JHW-type synthetic cannabinoids by having an indazole ring connected to an adamantyl group via a carboxamide linkage. Synthetic cannabinoids are completely metabolized, and identification of the metabolites is thus crucial when using urine as the sample matrix. Using an authentic urine sample and high-resolution accurate-mass Fourier transform Orbitrap mass spectrometry, we identified 16 phase-I metabolites of 5F-AKB-48. The modifications included mono-, di-, and trihydroxylation on the adamantyl ring alone or in combination with hydroxylation on the N-fluoropentylindazole moiety, dealkylation of the N-fluoropentyl side chain, and oxidative loss of fluorine as well as combinations thereof. The results were compared to human liver microsomal (HLM) incubations, which predominantly showed time-dependent formation of mono-, di-, and trihydroxylated metabolites having the hydroxyl groups on the adamantyl ring. The results presented here may be used to select metabolites specific of 5F-AKB-48 for use in clinical and forensic screening. Copyright © 2014 John Wiley & Sons, Ltd.

  14. Investigation of chemical modifiers for sulfur determination in diesel fuel samples by high-resolution continuum source graphite furnace molecular absorption spectrometry using direct analysis

    Energy Technology Data Exchange (ETDEWEB)

    Huber, Charles S. [Instituto Federal Sul-rio-grandense, Câmpus Pelotas, Pelotas, RS (Brazil); Universidade Federal do Rio Grande do Sul, Instituto de Química, Porto Alegre, RS (Brazil); Vale, Maria Goreti R. [Universidade Federal do Rio Grande do Sul, Instituto de Química, Porto Alegre, RS (Brazil); Instituto Nacional de Ciência e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, Salvador, BA (Brazil); Welz, Bernhard [Instituto Nacional de Ciência e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, Salvador, BA (Brazil); Universidade Federal de Santa Catarina, Departamento de Química, Florianópolis, SC (Brazil); Andrade, Jailson B. [Instituto Nacional de Ciência e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, Salvador, BA (Brazil); Dessuy, Morgana B., E-mail: mbdessuy@ufrgs.br [Universidade Federal do Rio Grande do Sul, Instituto de Química, Porto Alegre, RS (Brazil); Instituto Nacional de Ciência e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, Salvador, BA (Brazil)

    2015-06-01

    High-resolution continuum source graphite furnace molecular absorption spectrometry has been applied for sulfur determination in diesel fuel. The sharp rotational lines of the carbon monosulfide molecule (formed during the vaporization step) were used to measure the absorbance. The analytical line at 258.056 nm was monitored using the sum of three pixels. Different chemical modifiers were investigated and the mixture of palladium and magnesium was used as chemical modifier in combination with iridium as permanent modifier. L-Cysteine was chosen as sulfur standard and the calibration was done against aqueous standard solutions. The proposed method was applied for the analyses of four diesel samples: two S10 samples and two S500 samples. The trueness of the method was checked with a certified reference material (CRM) of sulfur in diesel fuel (NIST 2724b). Accurate results, for samples and CRM, were achieved after a dilution with propan-1-ol. The following figures of merit were obtained: characteristic mass of 17 ± 3 ng, limit of detection and limit of quantification of 1.4 mg kg{sup −1} and 4.7 mg kg{sup −1}, respectively. - Highlights: • Ir, Ru and Zr were investigated as permanent modifiers. • Ca, Mg, Pd and Pd/Mg were investigated as modifiers in solution. • Indirect determination of sulfur monitoring the molecular absorbance of the CS • Direct analysis of diesel samples using a dilution in propan-1-ol.

  15. [Screening and confirmation of 24 hormones in cosmetics by ultra high performance liquid chromatography-linear ion trap/orbitrap high resolution mass spectrometry].

    Science.gov (United States)

    Li, Zhaoyong; Wang, Fengmei; Niu, Zengyuan; Luo, Xin; Zhang, Gang; Chen, Junhui

    2014-05-01

    A method of ultra high performance liquid chromatography-linear ion trap/orbitrap high resolution mass spectrometry (UPLC-LTQ/Orbitrap MS) was established to screen and confirm 24 hormones in cosmetics. Various cosmetic samples were extracted with methanol. The extract was loaded onto a Waters ACQUITY UPLC BEH C18 column (50 mm x 2.1 mm, 1.7 microm) using a gradient elution of acetonitrile/water containing 0.1% (v/v) formic acid for the separation. The accurate mass of quasi-molecular ion was acquired by full scanning of electrostatic field orbitrap. The rapid screening was carried out by the accurate mass of quasi-molecular ion. The confirmation analysis for targeted compounds was performed with the retention time and qualitative fragments obtained by data dependent scan mode. Under the optimal conditions, the 24 hormones were routinely detected with mass accuracy error below 3 x 10(-6) (3 ppm), and good linearities were obtained in their respective linear ranges with correlation coefficients higher than 0.99. The LODs (S/N = 3) of the 24 compounds were hormones in 50 cosmetic samples. The results demonstrate that the method is a useful tool for the rapid screening and identification of the hormones in cosmetics.

  16. CaI and SrI molecules for iodine determination by high-resolution continuum source graphite furnace molecular absorption spectrometry: Greener molecules for practical application.

    Science.gov (United States)

    Zanatta, Melina Borges Teixeira; Nakadi, Flávio Venâncio; da Veiga, Márcia Andreia Mesquita Silva

    2018-03-01

    A new method to determine iodine in drug samples by high-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS GF MAS) has been developed. The method measures the molecular absorption of a diatomic molecule, CaI or SrI (less toxic molecule-forming reagents), at 638.904 or 677.692nm, respectively, and uses a mixture containing 5μg of Pd and 0.5μg of Mg as chemical modifier. The method employs pyrolysis temperatures of 1000 and 800°C and vaporization temperatures of 2300 and 2400°C for CaI and SrI, respectively. The optimized amounts of Ca and Sr as molecule-forming reagents are 100 and 150µg, respectively. On the basis of interference studies, even small chlorine concentrations reduce CaI and SrI absorbance significantly. The developed method was used to analyze different commercial drug samples, namely thyroid hormone pills with three different iodine amounts (15.88, 31.77, and 47.66µg) and one liquid drug with 1% m v -1 active iodine in their compositions. The results agreed with the values informed by the manufacturers (95% confidence level) regardless of whether CaI or SrI was determined. Therefore, the developed method is useful for iodine determination on the basis of CaI or SrI molecular absorption. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Application of surrogates, indicators, and high-resolution mass spectrometry to evaluate the efficacy of UV processes for attenuation of emerging contaminants in water.

    Science.gov (United States)

    Merel, Sylvain; Anumol, Tarun; Park, Minkyu; Snyder, Shane A

    2015-01-23

    In response to water scarcity, strategies relying on multiple processes to turn wastewater effluent into potable water are being increasingly considered by many cities. In such context, the occurrence of contaminants as well as their fate during treatment processes is a major concern. Three analytical approaches where used to characterize the efficacy of UV and UV/H2O2 processes on a secondary wastewater effluent. The first analytical approach assessed bulk organic parameters or surrogates before and after treatment, while the second analytical approach measured the removal of specific indicator compounds. Sixteen trace organic contaminants were selected due to their relative high concentration and detection frequency over eight monitoring campaigns. While their removal rate ranges from approximately 10 to >90%, some of these compounds can be used to gauge process efficacy (or failure). The third analytical approach assessed the fate of unknown contaminants through high-resolution time-of-flight (TOF) mass spectrometry with advanced data processing and demonstrated the occurrence of several thousand organic compounds in the water. A heat map clearly evidenced compounds as recalcitrant or transformed by the UV processes applied. In addition, those chemicals with similar fate were grouped together into clusters to identify new indicator compounds. In this manuscript, each approach is evaluated with advantages and disadvantages compared. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Development of a quantitation method to assay both lyoniresinol enantiomers in wines, spirits, and oak wood by liquid chromatography-high resolution mass spectrometry.

    Science.gov (United States)

    Cretin, Blandine N; Dubourdieu, Denis; Marchal, Axel

    2016-05-01

    Wine taste balance evolves during oak aging by the release of volatile and non-volatile compounds from wood. Among them, an enantiomer of lyoniresinol, (+)-lyoniresinol, has been shown to exhibit bitterness. To evaluate the impact of (+)-lyoniresinol on wine taste, a two-step quantitation method was developed and validated. First, (±)-lyoniresinol was assayed in wines, spirits, and oak wood macerates by C-18 liquid chromatography-high resolution mass spectrometry (LC-HRMS). Then, the lyoniresinol enantiomeric ratio was determined by chiral LC-HRMS in order to calculate the (+)-lyoniresinol content. In red and white wines, the average concentrations of (+)-lyoniresinol were 1.9 and 0.8 mg/L, respectively. The enantiomer proportions were not affected by bottle aging, and lyoniresinol appeared to remain stable over time. The sensory study of (+)-lyoniresinol established its perception threshold at 0.46 mg/L in wine. All the commercial wines quantitated were above this perception threshold, demonstrating its impact on wine taste by an increase in bitterness. In spirits, (+)-lyoniresinol ranged from 2.0 to 10.0 mg/L and was found to be released continuously during oak aging. Finally, neither botanical origin nor toasting was found to significantly affect the (+)-lyoniresinol content of oak wood. Graphical abstract From oak wood to wine: evaluation of the influence of (+)-lyoniresinol on the bitterness of wines and spirits.

  19. A new concept of efficient therapeutic drug monitoring using the high-resolution continuum source absorption spectrometry and the surface enhanced Raman spectroscopy

    Science.gov (United States)

    Xing, Yanlong; Fuss, Harald; Lademann, Jürgen; Huang, Mao Dong; Becker-Ross, Helmut; Florek, Stefan; Patzelt, Alexa; Meinke, Martina C.; Jung, Sora; Esser, Norbert

    2018-04-01

    In this study, a new therapeutic drug monitoring approach has been tested based on the combination of CaF molecular absorption using high-resolution continuum source absorption spectrometry (HR-CSAS) and surface enhanced Raman spectroscopy (SERS). HR-CSAS with mini graphite tube was successfully tested for clinical therapeutic drug monitoring of the fluorine-containing drug capecitabine in sweat samples of cancer patients: It showed advantageous features of high selectivity (no interference from Cl), high sensitivity (characteristic mass of 0.1 ng at CaF 583.069 nm), low sample consumption (down to 30 nL) and fast measurement (no sample pretreatment and less than 1 min of responding time) in tracing the fluorine signal out of capecitabine. However, this technique has the disadvantage of the total loss of the drug's structure information after burning the sample at very high temperature. Therefore, a new concept of combining HR-CSAS with a non-destructive spectroscopic method (SERS) was proposed for the sensitive sensing and specific identification of capecitabine. We tested and succeed in obtaining the molecular characteristics of the metabolite of capecitabine (named 5-fluorouracil) by the non-destructive SERS technique. With the results shown in this work, it is demonstrated that the combined spectroscopic technique of HR-CSAS and SERS will be very useful in efficient therapeutic drug monitoring in the future.

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

    Science.gov (United States)

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

    2015-05-01

    The open pit oil sands mining operations north of Fort McMurray, Alberta, Canada, are accumulating tailings waste at a rate approximately equal to 4.9 million m(3) /d. Naphthenic acids are among the most toxic components within tailings to aquatic life, but structural components have largely remained unidentified. In the present study, electrospray ionization high-resolution mass spectrometry (ESI-HRMS) and synchronous fluorescence spectroscopy (SFS) were used to characterize fractions derived from the distillation of an acid-extractable organics (AEO) mixture isolated from oil sands process-affected water (OSPW). Mean molecular weights of each fraction, and their relative proportions to the whole AEO extract, were as follows: fraction 1: 237 Da, 8.3%; fraction 2: 240 Da, 23.8%; fraction 3: 257 Da, 26.7%; fraction 4: 308 Da, 18.9%; fraction 5: 355 Da, 10.0%. With increasing mean molecular weight of the AEO fractions, a concurrent increase occurred in the relative abundance of nitrogen-, sulfur-, and oxygen-containing ions, double-bond equivalents, and degree of aromaticity. Structures present in the higher-molecular-weight fractions (fraction 4 and fraction 5) suggested the presence of heteroatoms, dicarboxyl and dihydroxy groups, and organic acid compounds with the potential to function as estrogens. Because organic acid compositions become dominated by more recalcitrant, higher-molecular-weight acids during natural degradation, these findings are important in the context of oil sands tailings pond water remediation. © 2015 SETAC.

  1. Quantification of the fluorine containing drug 5-fluorouracil in cancer cells by GaF molecular absorption via high-resolution continuum source molecular absorption spectrometry

    Science.gov (United States)

    Krüger, Magnus; Huang, Mao-Dong; Becker-Roß, Helmut; Florek, Stefan; Ott, Ingo; Gust, Ronald

    The development of high-resolution continuum source molecular absorption spectrometry made the quantification of fluorine feasible by measuring the molecular absorption as gallium monofluoride (GaF). Using this new technique, we developed on the example of 5-fluorouracil (5-FU) a graphite furnace method to quantify fluorine in organic molecules. The effect of 5-FU on the generation of the diatomic GaF molecule was investigated. The experimental conditions such as gallium nitrate amount, temperature program, interfering anions (represented as corresponding acids) and calibration for the determination of 5-FU in standard solution and in cellular matrix samples were investigated and optimized. The sample matrix showed no effect on the sensitivity of GaF molecular absorption. A simple calibration curve using an inorganic sodium fluoride solution can conveniently be used for the calibration. The described method is sensitive and the achievable limit of detection is 0.23 ng of 5-FU. In order to establish the concept of "fluorine as a probe in medicinal chemistry" an exemplary application was selected, in which the developed method was successfully demonstrated by performing cellular uptake studies of the 5-FU in human colon carcinoma cells.

  2. Dilute-and-shoot coupled to nanoflow liquid chromatography high resolution mass spectrometry for the determination of drugs of abuse and sport drugs in human urine.

    Science.gov (United States)

    Alcántara-Durán, Jaime; Moreno-González, David; Beneito-Cambra, Miriam; García-Reyes, Juan F

    2018-05-15

    In this work, a sensitive nanoflow liquid chromatography high-resolution mass spectrometry screening method has been developed for the determination of multiclass drugs of abuse and sport drugs in human urine. 81 drugs belonging to different multiclass pharmaceuticals were targeted. The method is based on the use of a nanoLC column (75 µm × 150 mm, 3 µm particle size and 100 Å pore) with the nanospray emitter tip integrated so that dead volumes are significantly minimized. Data acquisition method included both full-scan and all ion fragmentation experiments using an Orbitrap analyser (Q-Exactive) operated in the positive ionization mode. To increase laboratory throughput, a dilute-and-shoot methodology has been tested and proposed, based solely on direct urine dilution without further sample workup. Matrix effects were evaluated, showing a negligible effect for all studied compounds when a dilution 1:50 was implemented. Despite this high-dilution factor, limits of quantification were still satisfactory, with values below 5 µg L -1 in most cases, being lower than their minimum required performance limits correspond established by the World Anti-Doping Agency. Therefore, the use of the dilute-and-shoot method with the enhanced sensitivity provided by nanoflow LC setup could be useful tool for the determination of studied compounds in drug testing, thus increasing laboratory performance, because a minimum sample treatment steps are required. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. Exploring the Potential of a Global Emerging Contaminant Early Warning Network through the Use of Retrospective Suspect Screening with High-Resolution Mass Spectrometry.

    Science.gov (United States)

    Alygizakis, Nikiforos A; Samanipour, Saer; Hollender, Juliane; Ibáñez, María; Kaserzon, Sarit; Kokkali, Varvara; van Leerdam, Jan A; Mueller, Jochen F; Pijnappels, Martijn; Reid, Malcolm J; Schymanski, Emma L; Slobodnik, Jaroslav; Thomaidis, Nikolaos S; Thomas, Kevin V

    2018-04-13

    A key challenge in the environmental and exposure sciences is to establish experimental evidence of the role of chemical exposure in human and environmental systems. High resolution and accurate tandem mass spectrometry (HRMS) is increasingly being used for the analysis of environmental samples. One lauded benefit of HRMS is the possibility to retrospectively process data for (previously omitted) compounds that has led to the archiving of HRMS data. Archived HRMS data affords the possibility of exploiting historical data to rapidly and effectively establish the temporal and spatial occurrence of newly identified contaminants through retrospective suspect screening. We propose to establish a global emerging contaminant early warning network to rapidly assess the spatial and temporal distribution of contaminants of emerging concern in environmental samples through performing retrospective analysis on HRMS data. The effectiveness of such a network is demonstrated through a pilot study, where eight reference laboratories with available archived HRMS data retrospectively screened data acquired from aqueous environmental samples collected in 14 countries on 3 different continents. The widespread spatial occurrence of several surfactants (e.g., polyethylene glycols ( PEGs ) and C12AEO-PEGs ), transformation products of selected drugs (e.g., gabapentin-lactam, metoprolol-acid, carbamazepine-10-hydroxy, omeprazole-4-hydroxy-sulfide, and 2-benzothiazole-sulfonic-acid), and industrial chemicals (3-nitrobenzenesulfonate and bisphenol-S) was revealed. Obtaining identifications of increased reliability through retrospective suspect screening is challenging, and recommendations for dealing with issues such as broad chromatographic peaks, data acquisition, and sensitivity are provided.

  4. Fast and easy extraction combined with high resolution-mass spectrometry for residue analysis of two anticonvulsants and their transformation products in marine mussels.

    Science.gov (United States)

    Martínez Bueno, M J; Boillot, C; Fenet, H; Chiron, S; Casellas, C; Gómez, E

    2013-08-30

    Environmental field studies have shown that carbamazepine (Cbz) is one of the most frequently detected human pharmaceuticals in different aquatic compartments. However, little data is available on the detection of this substance and its transformation products in aquatic organisms. This study was thus mainly carried out to optimize and validate a simple and sensitive analytical methodology for the detection, characterization and quantification of Cbz and oxcarbazepine (Ox), two anticonvulsants, and six of their main transformation products in marine mussels (Mytilus galloprovincialis). A modified QuEChERS extraction method followed by analysis with liquid chromatography coupled to high resolution mass spectrometry (HRMS) was used. The analyses were performed using two-stage fragmentation to reveal the different fragmentation pathways that are highly useful for the identification of isomeric compounds, a common problem when several transformation products are analyzed. The developed analytical method allowed determination of the target analytes in the lower ng/g concentration levels. The mean recovery ranged from 67 to 110%. The relative standard deviation was under 11% in the intra-day and 18% in the inter-day analyses, respectively. Finally, the method was applied to marine mussel samples collected from Mediterranean Sea cultures in southeastern France. Residues of the psychiatric drug Cbz were occasionally found at levels up to 3.5ng/g dw. Lastly, in this study, other non-target compounds, such as caffeine, metoprolol, cotinine and ketoprofen, were identified in the real samples analyzed. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Screening of environmental contaminants in honey bee wax comb using gas chromatography-high-resolution time-of-flight mass spectrometry.

    Science.gov (United States)

    Gómez-Ramos, M M; García-Valcárcel, A I; Tadeo, J L; Fernández-Alba, A R; Hernando, M D

    2016-03-01

    This study reports an analytical approach intended to be used for investigation of non-targeted environmental contaminants and to characterize the organic pollution pattern of bee wax comb samples. The method comprises a generic extraction followed by detection with gas chromatography coupled to high-resolution time-of-flight mass spectrometry (GC-TOF-MS), operated in electron impact ionization (EI) mode. The screening approach for the investigation of non-targeted contaminants consisted of initial peak detection by deconvolution and matching the first-stage mass spectra EI-MS(1) with a nominal mass spectral library. To gain further confidence in the structural characterization of the contaminants under investigation, the molecular formula of representative ions (molecular ion when present in the EI spectrum) and, for at least other two fragment ions, was provided for those with an accurate mass scoring (mass error contaminants in 50 samples of bee wax comb. This approach has allowed the tentative identification of some GC-amenable contaminants belonging to different chemical groups, among them, phthalates and polycyclic aromatic hydrocarbons (PAHs), along with residues of veterinary treatments used in apiculture.

  6. Evaluation of solid sampling high-resolution continuum source graphite furnace atomic absorption spectrometry for direct determination of chromium in medicinal plants

    International Nuclear Information System (INIS)

    Virgilio, Alex; Nóbrega, Joaquim A.; Rêgo, Jardes F.; Neto, José A. Gomes

    2012-01-01

    A method for Cr determination in medicinal plants using direct solid sampling graphite furnace high-resolution continuum source atomic absorption spectrometry was developed. Modifiers were dispensable. Pyrolysis and atomization temperatures were 1500 °C and 2400 °C, respectively. Slopes of calibration curves (50–750 pg Cr, R 2 > 0.999) using aqueous and solid standards coincides in 96%, indicated feasibility of aqueous calibration for solid sampling of medicinal plants. Accuracy was checked by analysis of four plant certified reference materials. Results were in agreement at 95% confidence level with certified and non-certified values. Ten samples of medicinal plants were analyzed and Cr contents were in the 1.3–17.7 μg g −1 Cr range. The highest RSD (n = 5) was 15.4% for the sample Melissa officinalis containing 13.9 ± 2.1 μg g −1 Cr. The limit of detection was 3.3 ng g −1 Cr. - Highlights: ► Direct solid sampling is first time employed for Cr in plant materials. ► Calibration curves with liquids and solids are coincident. ► Microanalysis of plants for Cr is validated by reference materials. ► The proposed HR-CS GF AAS method is environmental friendly.

  7. Evaluation of solid sampling high-resolution continuum source graphite furnace atomic absorption spectrometry for direct determination of chromium in medicinal plants

    Energy Technology Data Exchange (ETDEWEB)

    Virgilio, Alex; Nobrega, Joaquim A. [Department of Chemistry, Federal University of Sao Carlos, Post Office Box 676, 13560-970, Sao Carlos-SP (Brazil); Rego, Jardes F. [Department of Analytical Chemistry, Institute of Chemistry, Sao Paulo State University-UNESP, Post Office Box 355, 14801-970, Araraquara-SP (Brazil); Neto, Jose A. Gomes, E-mail: anchieta@iq.unesp.br [Department of Analytical Chemistry, Institute of Chemistry, Sao Paulo State University-UNESP, Post Office Box 355, 14801-970, Araraquara-SP (Brazil)

    2012-12-01

    A method for Cr determination in medicinal plants using direct solid sampling graphite furnace high-resolution continuum source atomic absorption spectrometry was developed. Modifiers were dispensable. Pyrolysis and atomization temperatures were 1500 Degree-Sign C and 2400 Degree-Sign C, respectively. Slopes of calibration curves (50-750 pg Cr, R{sup 2} > 0.999) using aqueous and solid standards coincides in 96%, indicated feasibility of aqueous calibration for solid sampling of medicinal plants. Accuracy was checked by analysis of four plant certified reference materials. Results were in agreement at 95% confidence level with certified and non-certified values. Ten samples of medicinal plants were analyzed and Cr contents were in the 1.3-17.7 {mu}g g{sup -1} Cr range. The highest RSD (n = 5) was 15.4% for the sample Melissa officinalis containing 13.9 {+-} 2.1 {mu}g g{sup -1} Cr. The limit of detection was 3.3 ng g{sup -1} Cr. - Highlights: Black-Right-Pointing-Pointer Direct solid sampling is first time employed for Cr in plant materials. Black-Right-Pointing-Pointer Calibration curves with liquids and solids are coincident. Black-Right-Pointing-Pointer Microanalysis of plants for Cr is validated by reference materials. Black-Right-Pointing-Pointer The proposed HR-CS GF AAS method is environmental friendly.

  8. A novel method for the determination of mercury and selenium in shark tissue using high-resolution inductively coupled plasma-mass spectrometry

    International Nuclear Information System (INIS)

    Paul, Mitchell C.; Toia, Robert F.; Nagy-Felsobuki, Ellak I. von

    2003-01-01

    A method for measuring Hg and Se in shark tissue by high-resolution inductively coupled plasma mass spectrometry (HR-ICP-MS) has been developed. Using a matrix of 4% (v/v) aqueous methanol, the spray chamber and transfer tubing memory effects of Hg were significantly reduced. The methanol matrix was able to effectively wash out Hg (10 ppb) and return the signal to blank level in approximately 5 min. This enabled accurate and concomitant measurements of Hg and Se with detection limits (3σ blank signal, n=10) of 26 and 4 ppt, respectively. The recoveries of Hg and Se based on the CRM were 88 and 83%, respectively. The concentrations of Hg and Se in the (liver, muscle, kidney) of a hammerhead shark (dry weight) were (2.65±0.85, 7.09±1.32, 4.43±1.36) and (17.3±4.1, 1.28±0.29, 24.1±5.2) mg kg -1 (where the expanded uncertainty uses a k=2 value) respectively. Multi-elemental semi-quantitative analysis of a hammerhead shark liver, muscle and kidney revealed high levels of Cd, Zn and As

  9. Fast analysis of quaternary ammonium pesticides in food and beverages using cation-exchange chromatography coupled with isotope-dilution high-resolution mass spectrometry.

    Science.gov (United States)

    Nardin, Tiziana; Barnaba, Chiara; Abballe, Franco; Trenti, Gianmaria; Malacarne, Mario; Larcher, Roberto

    2017-10-01

    A fast separation based on cation-exchange liquid chromatography coupled with high-resolution mass spectrometry is proposed for simultaneous determination of chlormequat, difenzoquat, diquat, mepiquat and paraquat in several food and beverage commodities. Solid samples were extracted using a mixture of water/methanol/formic acid (69.6:30:0.4, v/v/v), while liquid samples were ten times diluted with the same solution. Separation was carried out on an experimental length-modified IonPac CS17 column (2 × 15 mm 2 ) that allowed the use of formic acid and acetonitrile as mobile phase. Detection limits for food and beverage matrices were established at 1.5 μg/L for chlormequat, difenzoquat and mepiquat, and 3 μg/L for diquat and paraquat, while for drinking water a pre-analytical sample concentration allowed detection limits of 9 and 20 ng/L, respectively. Precision, as repeatability (RSD%), ranged from 0.2 to 24%, with a median value of 6%, and trueness, as recovery, ranged from 64 to 118%, with a median value of 96%. The method developed was successfully applied to investigate the presence of herbicide residues in commercial commodities (mineral water, orange juice, beer, tea, green coffee bean, toasted coffee powder, cocoa bean, white corn flour, rice and sugar samples). © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Introducing AAA-MS, a rapid and sensitive method for amino acid analysis using isotope dilution and high-resolution mass spectrometry.

    Science.gov (United States)

    Louwagie, Mathilde; Kieffer-Jaquinod, Sylvie; Dupierris, Véronique; Couté, Yohann; Bruley, Christophe; Garin, Jérôme; Dupuis, Alain; Jaquinod, Michel; Brun, Virginie

    2012-07-06

    Accurate quantification of pure peptides and proteins is essential for biotechnology, clinical chemistry, proteomics, and systems biology. The reference method to quantify peptides and proteins is amino acid analysis (AAA). This consists of an acidic hydrolysis followed by chromatographic separation and spectrophotometric detection of amino acids. Although widely used, this method displays some limitations, in particular the need for large amounts of starting material. Driven by the need to quantify isotope-dilution standards used for absolute quantitative proteomics, particularly stable isotope-labeled (SIL) peptides and PSAQ proteins, we developed a new AAA assay (AAA-MS). This method requires neither derivatization nor chromatographic separation of amino acids. It is based on rapid microwave-assisted acidic hydrolysis followed by high-resolution mass spectrometry analysis of amino acids. Quantification is performed by comparing MS signals from labeled amino acids (SIL peptide- and PSAQ-derived) with those of unlabeled amino acids originating from co-hydrolyzed NIST standard reference materials. For both SIL peptides and PSAQ standards, AAA-MS quantification results were consistent with classical AAA measurements. Compared to AAA assay, AAA-MS was much faster and was 100-fold more sensitive for peptide and protein quantification. Finally, thanks to the development of a labeled protein standard, we also extended AAA-MS analysis to the quantification of unlabeled proteins.

  11. Determination of Chlorine in Milk via Molecular Absorption of SrCl Using High-Resolution Continuum Source Graphite Furnace Atomic Absorption Spectrometry.

    Science.gov (United States)

    Ozbek, Nil; Akman, Suleyman

    2016-07-20

    Total chlorine in milk was determined via the molecular absorption of diatomic strontium monochloride at 635.862 nm using high-resolution continuum source graphite furnace atomic absorption spectrometry. The effects of coating the graphite furnace, using different modifiers, amount of molecule-forming element, and different calibrants were investigated and optimized. Chlorine concentrations in milk samples were determined in a Zr-coated graphite furnace using 25 μg of Sr as the molecule-forming reagent and applying a pyrolysis temperature of 600 °C and a molecule-forming temperature of 2300 °C. Linearity was maintained up to 500 μg mL(-1) of Cl. The method was tested by analyzing a certified reference wastewater. The results were in the uncertainty limits of the certified value. The limit of detection of the method was 1.76 μg mL(-1). The chlorine concentrations in various cow milk samples taken from the market were found in the range of 588-1472 mg L(-1).

  12. Investigation of chemical modifiers for the direct determination of arsenic in fish oil using high-resolution continuum source graphite furnace atomic absorption spectrometry.

    Science.gov (United States)

    Pereira, Éderson R; de Almeida, Tarcísio S; Borges, Daniel L G; Carasek, Eduardo; Welz, Bernhard; Feldmann, Jörg; Campo Menoyo, Javier Del

    2016-04-01

    High-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GF AAS) has been applied for the development of a method for the determination of total As in fish oil samples using direct analysis. The method does not use any sample pretreatment, besides dilution with 1-propanole, in order to decrease the oil viscosity. The stability and sensitivity of As were evaluated using ruthenium and iridium as permanent chemical modifiers and palladium added in solution over the sample. The best results were obtained with ruthenium as the permanent modifier and palladium in solution added to samples and standard solutions. Under these conditions, aqueous standard solutions could be used for calibration for the fish oil samples diluted with 1-propanole. The pyrolysis and atomization temperatures were 1400 °C and 2300 °C, respectively, and the limit of detection and characteristic mass were 30 pg and 43 pg, respectively. Accuracy and precision of the method have been evaluated using microwave-assisted acid digestion of the samples with subsequent determination by HR-CS GF AAS and ICP-MS; the results were in agreement (95% confidence level) with those of the proposed method. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Micro-sampling method based on high-resolution continuum source graphite furnace atomic absorption spectrometry for calcium determination in blood and mitochondrial suspensions.

    Science.gov (United States)

    Gómez-Nieto, Beatriz; Gismera, Mª Jesús; Sevilla, Mª Teresa; Satrústegui, Jorgina; Procopio, Jesús R

    2017-08-01

    A micro-sampling and straightforward method based on high resolution continuum source atomic absorption spectrometry (HR-CS AAS) was developed to determine extracellular and intracellular Ca in samples of interest in clinical and biomedical analysis. Solid sampling platforms were used to introduce the micro-samples into the graphite furnace atomizer. The secondary absorption line for Ca, located at 239.856nm, was selected to carry out the measurements. Experimental parameters such as pyrolysis and atomization temperatures and the amount of sample introduced for the measurements were optimized. Calibration was performed using aqueous standards and the approach to measure at the wings of the absorption lines was employed for the expansion of the linear response range. The limit of detection was of 0.02mgL -1 Ca (0.39ng Ca) and the upper limit of linear range was increased up to 8.0mgL -1 Ca (160ng Ca). The proposed method was used to determine Ca in mitochondrial suspensions and whole blood samples with successful results. Adequate recoveries (within 91-107%) were obtained in the tests performed for validation purposes. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Molecular-level characterization of crude oil compounds combining reversed-phase high-performance liquid chromatography with off-line high-resolution mass spectrometry

    Science.gov (United States)

    Sim, Arum; Cho, Yunju; Kim, Daae; Witt, Matthias; Birdwell, Justin E.; Kim, Byung Ju; Kim, Sunghwan

    2014-01-01

    A reversed-phase separation technique was developed in a previous study (Loegel et al., 2012) and successfully applied to the de-asphalted fraction of crude oil. However, to the best of our knowledge, the molecular-level characterization of oil fractions obtained by reversed-phase high-performance liquid chromatography (HPLC) coupled with high-resolution mass spectrometry (MS) has not yet been reported. A detailed characterization of the oil fractions prepared by reversed-phase HPLC was performed in this study. HPLC fractionation was carried out on conventional crude oil and an oil shale pyrolysate. The analyses of the fractions showed that the carbon number of alkyl chains and the double bond equivalent (DBE) value were the major factors determining elution order. The compounds with larger DBE (presumably more condensed aromatic structures) and smaller carbon number (presumably compounds with short side chains) were eluted earlier but those compounds with lower DBE values (presumably less aromatic structures) and higher carbon number (presumably compounds with longer alkyl chains) eluted later in the chromatograms. This separation behavior is in good agreement with that expected from the principles of reversed-phase separation. The data presented in this study show that reversed-phase chromatography is effective in separating crude oil compounds and can be combined with ultrahigh-resolution MS data to better understand natural oils and oil shale pyrolysates.

  15. Development and validation of a QuEChERS method coupled to liquid chromatography and high resolution mass spectrometry to determine pyrrolizidine and tropane alkaloids in honey.

    Science.gov (United States)

    Martinello, Marianna; Borin, Alice; Stella, Roberto; Bovo, Davide; Biancotto, Giancarlo; Gallina, Albino; Mutinelli, Franco

    2017-11-01

    Awareness about pyrrolizidine alkaloids (PAs) and tropane alkaloids (TAs) in food was recently raised by the European Food Safety Authority stressing the lack of data and gaps of knowledge required to improve the risk assessment strategy. The present study aimed at the elaboration and validation of a method to determine PAs and TAs in honey. QuEChERS sample treatment and liquid chromatography coupled to hybrid high resolution mass spectrometry, were used. The method resulted in good linearity (R 2 >0.99) and low limits of detection and quantification, ranging from 0.04 to 0.2µgkg -1 and from 0.1 to 0.7µgkg -1 respectively. Recoveries ranged from 92.3 to 114.8% with repeatability lying between 0.9 and 15.1% and reproducibility between 1.1 and 15.6%. These performances demonstrate the selectivity and sensitivity of the method for simultaneous trace detection and quantification of PAs and TAs in honey, verified through the analysis of forty commercial samples. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Studies on the microbial biotransformation of the novel psychoactive substance methylenedioxypyrovalerone (MDPV) in wastewater by means of liquid chromatography-high resolution mass spectrometry/mass spectrometry.

    Science.gov (United States)

    Mardal, Marie; Meyer, Markus R

    2014-09-15

    Sewage profiling as a mean to estimate consumption of drugs of abuse is gaining increasing attention. However, only scarce data are available so far on the impact of microbial biotransformation on the presence and hence detectability of drugs of abuse and their metabolites in wastewater (WW) samples. The aim of this work was therefore to study the biotransformation pathways of the novel psychoactive substance 3,4-methylenedioxypyrovalerone (MPDV) in WW by incubating it, based on the OECD guideline 314 A. MDPV was incubated (100 μg/L) for 10d at 22 °C in WW from a local WW treatment plant. Furthermore, urine and feces collected from rats administered 20mg MDPV/kg BW were incubated correspondingly. Samples were worked-up either by centrifugation/filtration and solid-phase (HCX) extraction or QuEChERS. High resolution (HR) mass spectra (MS) were recorded using an Orbitrap mass spectrometer. All products were identified via their HR-MS(2) spectra and chromatographic properties. The observed biotransformations in WW were: demethylenation and subsequent O-methylation, hydroxylation at the phenyl part, hydroxylation at the pyrrolidine part with subsequent methylation or oxidation, N-demethylation, and hydroxylation at the alkyl part as well as combination of them. In total, 12 biotransformation products were identified after 10 days of incubation. Three of these biotransformation products were previously reported to be also rat and human metabolites. No additional MDPV biotransformation products could be found after incubating the rat urine and feces samples. Instead, the urinary phase II glucuronides were nearly completely cleaved after one day of WW incubation. The presented study indicates that demethylenyl-methyl MDPV, the most abundant metabolite in human urine, should be the best indicator in WW to estimate its use. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Bioconversion of red ginseng saponins in the gastro-intestinal tract in vitro model studied by high-performance liquid chromatography-high resolution Fourier transform ion cyclotron resonance mass spectrometry

    NARCIS (Netherlands)

    Kong, H.; Wang, M.; Venema, K.; Maathuis, A.; Heijden, R. van der; Greef, J. van der; Xu, G.; Hankemeier, T.

    2009-01-01

    A high-performance liquid chromatography-high resolution Fourier transform ion cyclotron resonance mass spectrometry (HPLC-FTICR-MS) method was developed to investigate the metabolism of ginsenosides in in vitro models of the gastro-intestinal tract. The metabolites were identified by

  18. Portable gamma-ray spectrometers and spectrometry systems

    International Nuclear Information System (INIS)

    Shebell, P.

    1999-01-01

    The current state-of-the-art in portable gamma-ray spectrometers and portable spectrometry systems is discussed. A comparison of detector performance and features of commercially available systems are summarised. Finally, several applications of portable systems are described. (author)

  19. Determination of uranium-235 by differential gamma spectrometry

    International Nuclear Information System (INIS)

    Suner, A.A.; La Gamma de Batistoni, A.M.G.; Botbol, J.

    1974-12-01

    A method for the determination of U-235 contained in solutions of uranium, by gamma spectrometry with Ge(Li) detector is described. Ra-226 is coprecipitated in BaSO 4 . The activity at 186 keV is measured, substracted by the corresponding of a standard. The detection limit is 1% of increment of U-235 over the standard. (author)

  20. Coupling of gas chromatography and electrospray ionization high resolution mass spectrometry for the analysis of anabolic steroids as trimethylsilyl derivatives in human urine.

    Science.gov (United States)

    Cha, Eunju; Jeong, Eun Sook; Cha, Sangwon; Lee, Jaeick

    2017-04-29

    In this study, gas chromatography (GC) was interfaced with high resolution mass spectrometry (HRMS) with electrospray ionization source (ESI) and the relevant parameters were investigated to enhance the ionization efficiency. In GC-ESI, the distances (x-, y- and z) and angle between the ESI needle, GC capillary column and MS orifice were set to 7 (x-distance), 4 (y-distance), and 1 mm (z-distance). The ESI spray solvent, acid modifier and nebulizer gas flow were methanol, 0.1% formic acid and 5 arbitrary units, respectively. Based on these results, analytical conditions for GC-ESI/HRMS were established. In particular, the results of spray solvent flow indicated a concentration-dependent mechanism (peak dilution effect), and other parameters also greatly influenced the ionization performance. The developed GC-ESI/HRMS was then applied to the analysis of anabolic steroids as trimethylsilyl (TMS) derivatives in human urine to demonstrate its application. The ionization profiles of TMS-derivatized steroids were investigated and compared with those of underivatized steroids obtained from gas chromatography-electrospray ionization/mass spectrometry (GC-ESI/MS) and liquid chromatography-electrospray ionization/mass spectrometry (LC-ESI/MS). The steroids exhibited ionization profiles based on their structural characteristics, regardless of the analyte phase or derivatization. Groups I and II with conjugated or unconjugated keto functional groups at C3 generated the [M+H] + and [M+H-TMS] + ions, respectively. On the other hand, Groups III and IV gave rise to the characteristic fragment ions [M+H-TMS-H 2 O] + and [M+H-2TMS-H 2 O] + , corresponding to loss of a neutral TMS·H 2 O moiety from the protonated molecular ion by in-source dissociation. To the best of our knowledge, this is the first study to successfully ionize and analyze steroids as TMS derivatives using ESI coupled with GC. The present system has enabled the ionization of TMS derivatives under ESI conditions

  1. Detection of anabolic and androgenic steroids and/or their esters in horse hair using ultra-high performance liquid chromatography-high resolution mass spectrometry.

    Science.gov (United States)

    Kwok, Karen Y; Choi, Timmy L S; Kwok, Wai Him; Wong, Jenny K Y; Wan, Terence S M

    2017-04-14

    Anabolic and androgenic steroids (AASs) are a class of prohibited substances banned in horseracing at all times. The common approach for controlling the misuse of AASs in equine sports is by detecting the presence of AASs and/or their metabolites in urine and blood samples using gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS). This approach, however, often falls short as the duration of effect for many AASs are longer than their detection time in both urine and blood. As a result, there is a high risk that such AASs could escape detection in their official race-day samples although they may have been used during the long period of training. Hair analysis, on the other hand, can afford significantly longer detection windows. In addition, the identification of synthetic ester derivatives of AASs in hair, particularly for the endogenous ones, can provide unequivocal proof of their exogenous origin. This paper describes the development of a sensitive method (at sub to low parts-per-billion or ppb levels) for detecting 48 AASs and/or their esters in horse hair using ultra-high performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS). Decontaminated horse hair was pulverised and subjected to in-situ liquid-liquid extraction in a mixture of hexane - ethyl acetate (7:3, v/v) and phosphate buffer (0.1M, pH 9.5), followed by additional clean-up using mixed-mode solid-phase extraction. The final extract was analysed using UHPLC-HRMS in the positive electrospray ionisation (ESI) mode with both full scan and parallel reaction monitoring (PRM). This method was validated for qualitative identification purposes. Validation data, including method specificity, method sensitivity, extraction recovery, method precision and matrix effect are presented. Method applicability was demonstrated by the successful detection and confirmation of testosterone propionate in a referee hair sample. To our knowledge, this was

  2. Suspected-target pesticide screening using gas chromatography-quadrupole time-of-flight mass spectrometry with high resolution deconvolution and retention index/mass spectrum library.

    Science.gov (United States)

    Zhang, Fang; Wang, Haoyang; Zhang, Li; Zhang, Jing; Fan, Ruojing; Yu, Chongtian; Wang, Wenwen; Guo, Yinlong

    2014-10-01

    A strategy for suspected-target screening of pesticide residues in complicated matrices was exploited using gas chromatography in combination with hybrid quadrupole time-of-flight mass spectrometry (GC-QTOF MS). The screening workflow followed three key steps of, initial detection, preliminary identification, and final confirmation. The initial detection of components in a matrix was done by a high resolution mass spectrum deconvolution; the preliminary identification of suspected pesticides was based on a special retention index/mass spectrum (RI/MS) library that contained both the first-stage mass spectra (MS(1) spectra) and retention indices; and the final confirmation was accomplished by accurate mass measurements of representative ions with their response ratios from the MS(1) spectra or representative product ions from the second-stage mass spectra (MS(2) spectra). To evaluate the applicability of the workflow in real samples, three matrices of apple, spinach, and scallion, each spiked with 165 test pesticides in a set of concentrations, were selected as the models. The results showed that the use of high-resolution TOF enabled effective extractions of spectra from noisy chromatograms, which was based on a narrow mass window (5 mDa) and suspected-target compounds identified by the similarity match of deconvoluted full mass spectra and filtering of linear RIs. On average, over 74% of pesticides at 50 ng/mL could be identified using deconvolution and the RI/MS library. Over 80% of pesticides at 5 ng/mL or lower concentrations could be confirmed in each matrix using at least two representative ions with their response ratios from the MS(1) spectra. In addition, the application of product ion spectra was capable of confirming suspected pesticides with specificity for some pesticides in complicated matrices. In conclusion, GC-QTOF MS combined with the RI/MS library seems to be one of the most efficient tools for the analysis of suspected-target pesticide residues

  3. A simple method for the deconvolution of 134 Cs/137 Cs peaks in gamma-ray scintillation spectrometry

    International Nuclear Information System (INIS)

    Darko, E.O.; Osae, E.K.; Schandorf, C.

    1998-01-01

    A simple method for the deconvolution of 134 Cs / 137 Cs peaks in a given mixture of 134 Cs and 137 Cs using Nal(TI) gamma-ray scintillation spectrometry is described. In this method the 795 keV energy of 134 Cs is used as a reference peak to calculate the activity of the 137 Cs directly from the measured peaks. Certified reference materials were measured using the method and compared with a high resolution gamma-ray spectrometry measurements. The results showed good agreement with the certified values. The method is very simple and does not need any complicated mathematics and computer programme to de- convolute the overlapping 604.7 keV and 661.6 keV peaks of 134 Cs and 137 Cs respectively. (author). 14 refs.; 1 tab., 2 figs

  4. Evaluation of gamma-spectrometry equipment for on-site inspection

    International Nuclear Information System (INIS)

    Burnett, J.L.; Milbrath, B.D.; Mueller, W.F.

    2017-01-01

    An On-site Inspection (OSI) is an important component of the verification regime of the Comprehensive Nuclear-Test-Ban Treaty (CTBT), with the objective of gathering evidence of a possible Treaty violation. This includes the use of gamma-spectrometry equipment to identify 17 particulate radionuclides that are indicative of a nuclear explosion. This research provides an evaluation of high- (germanium), medium- (cadmium zinc telluride) and low-resolution (sodium iodide and lanthanum bromide) detectors using modelled radionuclide signatures from a nuclear explosion and Monte Carlo simulations of a detector response. The complex radionuclide signatures are shown to only be distinguishable using a high-resolution system for 1 week and 1 year post-detonation cases. (author)

  5. The software quality control for gamma spectrometry

    International Nuclear Information System (INIS)

    Monte, L.

    1986-01-01

    One of major problems with wich the quality control program of an environmental measurements laboratory is confronted is the evaluation of the performances of software packages for the analysis of gamma-ray spectra. A program of tests for evaluating the performances of the software package (SPECTRAN-F, Canberra Inc.) used by our laboratory is being carried out. In this first paper the results of a preliminary study concerning the evaluation of the performance of the doublet analysis routine are presented

  6. Pulser injection with subsequent removal for gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Hartwell, J.K.; Goodwin, S.G.; Johnson, L.O.; Killian, E.W.

    1990-01-01

    This patent describes a module for use with a gamma-ray spectroscopy system. The system includes a gamma-ray detector for detecting gamma-ray events and producing a signal representing the gamma-ray events, a converter responsive to the detector and capable of converting the signal to a spectrum, a storage memory responsive to the converter and capable of storing the spectrum at address locations in memory, and a pulser capable of injecting pulses into the signal produced by the detector. The module comprises: means for generating a logic pulse for controlling the pulser, the controlling means adapted for coupling to the pulser; means for generating separation of events logic to isolate the components of a combined gamma-ray---pulse spectrum, the separation of events logic means adapted for coupling to the converter and the storage memory with the capability of storing pulses at address locations in the storage memory separate from the gamma-ray events; means for receiving an imitating signal from the converter to generate a plurality of operations by the module; means for tracking variations in a gamma-ray---pulse spectrum brought on by external parameter changes; and means for interfacing with commercially developed gamma-ray spectrometry equipment

  7. Simultaneous analysis of polychlorinated biphenyls and polychlorinated naphthalenes by isotope dilution comprehensive two-dimensional gas chromatography high-resolution time-of-flight mass spectrometry

    International Nuclear Information System (INIS)

    Xia, Dan; Gao, Lirong; Zheng, Minghui; Wang, Shasha; Liu, Guorui

    2016-01-01

    Polychlorinated biphenyls (PCBs) and polychlorinated naphthalenes (PCNs) are listed as persistent organic pollutants (POPs) under the Stockholm Convention. Because they have similar physical and chemical properties, they are coeluted and are usually analyzed separately by different gas chromatography high-resolution mass spectrometry (GC-HRMS) methods. In this study, a novel method was developed for simultaneous analysis of six indicator PCBs, 12 dioxin-like PCBs, and 16 PCNs using isotope dilution comprehensive two-dimensional gas chromatography with high-resolution time-of-flight mass spectrometry (GC × GC-HRTOF-MS). The method parameters, including the type of GC column, oven temperature program, and modulation period, were systematically optimized. Complete separation of all target analytes and the matrix was achieved with a DB-XLB column in the first dimension and a BPX-70 column in the second dimension. The isotope dilution method was used for quantification of the PCBs and PCNs by GC × GC-HRTOF-MS. The method showed good linearity from 5 to 500 pg μL"−"1 for all the target compounds. The instrumental limit of detection ranged from 0.03 to 0.3 pg μL"−"1 for the 18 PCB congeners and from 0.09 to 0.6 pg μL"−"1 for the 16 PCN congeners. Repeatability for triplicate injections was always lower than 20%. The method was successfully applied to the determination of 18 PCBs present at 0.9–2054 pg g"−"1 and 16 PCNs present at 0.2–15.7 pg g"−"1 in three species of fish. The GC × GC-HRTOF-MS results agreed with those obtained by GC-HRMS. The GC × GC-HRTOF-MS method proved to be a sensitive and accurate technique for simultaneous analysis of the selected PCBs and PCNs. With the excellent chromatographic separation offered by GC × GC and accurate mass measurements offered by HRTOF-MS, this method allowed identification of non-target contaminants in the fish samples, including organochlorine pesticides and polycyclic aromatic

  8. Simultaneous analysis of polychlorinated biphenyls and polychlorinated naphthalenes by isotope dilution comprehensive two-dimensional gas chromatography high-resolution time-of-flight mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Dan [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); University of Chinese Academy of Sciences, Beijing 100085 (China); Gao, Lirong, E-mail: gaolr@rcees.ac.cn [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Zheng, Minghui; Wang, Shasha; Liu, Guorui [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China)

    2016-09-21

    Polychlorinated biphenyls (PCBs) and polychlorinated naphthalenes (PCNs) are listed as persistent organic pollutants (POPs) under the Stockholm Convention. Because they have similar physical and chemical properties, they are coeluted and are usually analyzed separately by different gas chromatography high-resolution mass spectrometry (GC-HRMS) methods. In this study, a novel method was developed for simultaneous analysis of six indicator PCBs, 12 dioxin-like PCBs, and 16 PCNs using isotope dilution comprehensive two-dimensional gas chromatography with high-resolution time-of-flight mass spectrometry (GC × GC-HRTOF-MS). The method parameters, including the type of GC column, oven temperature program, and modulation period, were systematically optimized. Complete separation of all target analytes and the matrix was achieved with a DB-XLB column in the first dimension and a BPX-70 column in the second dimension. The isotope dilution method was used for quantification of the PCBs and PCNs by GC × GC-HRTOF-MS. The method showed good linearity from 5 to 500 pg μL{sup −1} for all the target compounds. The instrumental limit of detection ranged from 0.03 to 0.3 pg μL{sup −1} for the 18 PCB congeners and from 0.09 to 0.6 pg μL{sup −1} for the 16 PCN congeners. Repeatability for triplicate injections was always lower than 20%. The method was successfully applied to the determination of 18 PCBs present at 0.9–2054 pg g{sup −1} and 16 PCNs present at 0.2–15.7 pg g{sup −1} in three species of fish. The GC × GC-HRTOF-MS results agreed with those obtained by GC-HRMS. The GC × GC-HRTOF-MS method proved to be a sensitive and accurate technique for simultaneous analysis of the selected PCBs and PCNs. With the excellent chromatographic separation offered by GC × GC and accurate mass measurements offered by HRTOF-MS, this method allowed identification of non-target contaminants in the fish samples, including organochlorine pesticides and

  9. Metrological characterization of the numerical system Adonis for gamma spectrometry; Caracterisation metrologique du systeme de spectrometrie gamma numerique Adonis

    Energy Technology Data Exchange (ETDEWEB)

    Plagnard, J.; Morel, J.; Tran Tuan, A

    2005-07-01

    In gamma spectrometry, new acquisition systems based on digital processing of the signals are now available on the market. In order to determine their performances at high count rates, The CEA-LNHB (Commissariat a l'Energie Atomique - Laboratoire National Henri Becquerel) has tested several of these equipments.. These tests have clearly shown that the performances announced by the manufacturers were generally not met. At this point, it was interesting to include in these tests, the system ADONIS (Atelier de Developpement Numerique pour l'Instrumentation en Spectrometrie), which is the new gamma spectrometry system, developed by the CEA-SIAR (Service d'Instrumentation et d'Application des Rayonnements). (authors)

  10. Mildronate (Meldonium) in professional sports - monitoring doping control urine samples using hydrophilic interaction liquid chromatography - high resolution/high accuracy mass spectrometry.

    Science.gov (United States)

    Görgens, Christian; Guddat, Sven; Dib, Josef; Geyer, Hans; Schänzer, Wilhelm; Thevis, Mario

    2015-01-01

    To date, substances such as Mildronate (Meldonium) are not on the radar of anti-doping laboratories as the compound is not explicitly classified as prohibited. However, the anti-ischemic drug Mildronate demonstrates an increase in endurance performance of athletes, improved rehabilitation after exercise, protection against stress, and enhanced activations of central nervous system (CNS) functions. In the present study, the existing evidence of Mildronate's usage in sport, which is arguably not (exclusively) based on medicinal reasons, is corroborated by unequivocal analytical data allowing the estimation of the prevalence and extent of misuse in professional sports. Such data are vital to support decision-making processes, particularly regarding the ban on drugs in sport. Due to the growing body of evidence (black market products and athlete statements) concerning its misuse in sport, adequate test methods for the reliable identification of Mildronate are required, especially since the substance has been added to the 2015 World Anti-Doping Agency (WADA) monitoring program. In the present study, two approaches were established using an in-house synthesized labelled internal standard (Mildronate-D3 ). One aimed at the implementation of the analyte into routine doping control screening methods to enable its monitoring at the lowest possible additional workload for the laboratory, and another that is appropriate for the peculiar specifics of the analyte, allowing the unequivocal confirmation of findings using hydrophilic interaction liquid chromatography-high resolution/high accuracy mass spectrometry (HILIC-HRMS). Here, according to applicable regulations in sports drug testing, a full qualitative validation was conducted. The assay demonstrated good specificity, robustness (rRT=0.3%), precision (intra-day: 7.0-8.4%; inter-day: 9.9-12.9%), excellent linearity (R>0.99) and an adequate lower limit of detection (<10 ng/mL). Copyright © 2015 John Wiley & Sons, Ltd.

  11. Mildronate (Meldonium) in professional sports – monitoring doping control urine samples using hydrophilic interaction liquid chromatography – high resolution/high accuracy mass spectrometry

    Science.gov (United States)

    Görgens, Christian; Dib, Josef; Geyer, Hans; Schänzer, Wilhelm; Thevis, Mario

    2015-01-01

    To date, substances such as Mildronate (Meldonium) are not on the radar of anti‐doping laboratories as the compound is not explicitly classified as prohibited. However, the anti‐ischemic drug Mildronate demonstrates an increase in endurance performance of athletes, improved rehabilitation after exercise, protection against stress, and enhanced activations of central nervous system (CNS) functions. In the present study, the existing evidence of Mildronate's usage in sport, which is arguably not (exclusively) based on medicinal reasons, is corroborated by unequivocal analytical data allowing the estimation of the prevalence and extent of misuse in professional sports. Such data are vital to support decision‐making processes, particularly regarding the ban on drugs in sport. Due to the growing body of evidence (black market products and athlete statements) concerning its misuse in sport, adequate test methods for the reliable identification of Mildronate are required, especially since the substance has been added to the 2015 World Anti‐Doping Agency (WADA) monitoring program. In the present study, two approaches were established using an in‐house synthesized labelled internal standard (Mildronate‐D3). One aimed at the implementation of the analyte into routine doping control screening methods to enable its monitoring at the lowest possible additional workload for the laboratory, and another that is appropriate for the peculiar specifics of the analyte, allowing the unequivocal confirmation of findings using hydrophilic interaction liquid chromatography‐high resolution/high accuracy mass spectrometry (HILIC‐HRMS). Here, according to applicable regulations in sports drug testing, a full qualitative validation was conducted. The assay demonstrated good specificity, robustness (rRT=0.3%), precision (intra‐day: 7.0–8.4%; inter‐day: 9.9–12.9%), excellent linearity (R>0.99) and an adequate lower limit of detection (<10 ng/mL). © 2015 The Authors

  12. Simplifying and expanding analytical capabilities for various classes of doping agents by means of direct urine injection high performance liquid chromatography high resolution/high accuracy mass spectrometry.

    Science.gov (United States)

    Görgens, Christian; Guddat, Sven; Thomas, Andreas; Wachsmuth, Philipp; Orlovius, Anne-Katrin; Sigmund, Gerd; Thevis, Mario; Schänzer, Wilhelm

    2016-11-30

    So far, in sports drug testing compounds of different classes are processed and measured using different screening procedures. The constantly increasing number of samples in doping analysis, as well as the large number of substances with doping related, pharmacological effects require the development of even more powerful assays than those already employed in sports drug testing, indispensably with reduced sample preparation procedures. The analysis of native urine samples after direct injection provides a promising analytical approach, which thereby possesses a broad applicability to many different compounds and their metabolites, without a time-consuming sample preparation. In this study, a novel multi-target approach based on liquid chromatography and high resolution/high accuracy mass spectrometry is presented to screen for more than 200 analytes of various classes of doping agents far below the required detection limits in sports drug testing. Here, classic groups of drugs as diuretics, stimulants, β 2 -agonists, narcotics and anabolic androgenic steroids as well as various newer target compounds like hypoxia-inducible factor (HIF) stabilizers, selective androgen receptor modulators (SARMs), selective estrogen receptor modulators (SERMs), plasma volume expanders and other doping related compounds, listed in the 2016 WADA prohibited list were implemented. As a main achievement, growth hormone releasing peptides could be implemented, which chemically belong to the group of small peptides (0.99), limit of detection (0.1-25ng/mL; 3'OH-stanozolol glucuronide: 50pg/mL; dextran/HES: 10μg/mL) and matrix effects. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Target analysis of primary aromatic amines combined with a comprehensive screening of migrating substances in kitchen utensils by liquid chromatography-high resolution mass spectrometry.

    Science.gov (United States)

    Sanchis, Yovana; Coscollà, Clara; Roca, Marta; Yusà, Vicent

    2015-06-01

    An analytical strategy including both the quantitative target analysis of 8 regulated primary aromatic amines (PAAs), as well as a comprehensive post-run target screening of 77 migrating substances, was developed for nylon utensils, using liquid chromatography-orbitrap-high resolution mass spectrometry (LC-HRMS) operating in full scan mode. The accurate mass data were acquired with a resolving power of 50,000 FWHM (scan speed, 2 Hz), and by alternating two acquisition events, ESI+ with and without fragmentation. The target method was validated after statistical optimization of the main ionization and fragmentation parameters. The quantitative method presented appropriate performance to be used in official monitoring with recoveries ranging from 78% to 112%, precision in terms of Relative Standard Deviation (RSD) was less than 15%, and the limits of quantification were between 2 and 2.5 µg kg(-1). For post-target screening, a customized theoretical database was built for food contact material migrants, including bisphenols, phthalates, and other amines. For identification purposes, accurate exact mass (<5 ppm) and some diagnostic ions including fragments were used. The strategy was applied to 10 real samples collected from different retailers in the Valencian Region (Spain) during 2014. Six out of eight target PAAs were detected in at least one sample in the target analysis. The most frequently detected compounds were 4,4'-methylenedianiline and aniline, with concentrations ranging from 2.4 to 19,715 µg kg(-1) and 2.5 to 283 µg kg(-1), respectively. Two phthalates were identified and confirmed in the post-run target screening analysis. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. On the possibilities of high-resolution continuum source graphite furnace atomic absorption spectrometry for the simultaneous or sequential monitoring of multiple atomic lines

    International Nuclear Information System (INIS)

    Resano, M.; Rello, L.; Florez, M.; Belarra, M.A.

    2011-01-01

    This paper explores the potential of commercially available high-resolution continuum source graphite furnace atomic absorption spectrometry instrumentation for the simultaneous or sequential monitoring of various atomic lines, in an attempt to highlight the analytical advantages that can be derived from this strategy. In particular, it is demonstrated how i) the monitoring of multiplets may allow for the simple expansion of the linear range, as shown for the measurement of Ni using the triplet located in the vicinity of 234.6 nm; ii) the use of a suitable internal standard may permit improving the precision and help in correcting for matrix-effects, as proved for the monitoring of Ni in different biological samples; iii) direct and multi-element analysis of solid samples may be feasible on some occasions, either by monitoring various atomic lines that are sufficiently close (truly simultaneous monitoring, as demonstrated in the determination of Co, Fe and Ni in NIST 1566a Oyster tissue) or, alternatively, by opting for a selective and sequential atomization of the elements of interest during every single replicate. Determination of Cd and Ni in BCR 679 White cabbage is attempted using both approaches, which permits confirming that both methods can offer very similar and satisfactory results. However, it is important to stress that the second approach provides more flexibility, since analysis is no longer limited to those elements that show very close atomic lines (closer than 0.3 nm in the ultraviolet region) with a sensitivity ratio similar to the concentration ratio of the analytes in the samples investigated.

  15. Identification and quantification of the main isoflavones and other phytochemicals in soy based nutraceutical products by liquid chromatography-orbitrap high resolution mass spectrometry.

    Science.gov (United States)

    López-Gutiérrez, Noelia; Romero-González, Roberto; Garrido Frenich, Antonia; Martínez Vidal, José Luis

    2014-06-27

    The specific phytochemicals composition of soy nutritional supplements is usually not labelled. Hence, 12 dietary supplements were analyzed in order to detect and identify the main phytochemicals present in these samples, using a database containing 60 compounds. Ultra-high performance liquid chromatography coupled to single-stage Orbitrap high resolution mass spectrometry (UHPLC-Orbitrap-MS) has been used. Two consecutive extractions, using as extraction solvent a mixture of methanol:water (80:20, v/v), were employed, followed by two dilutions (10 or 100 times depending on the concentration of the components in the sample) with a mixture of an aqueous solution of ammonium acetate 30mM:methanol (50:50, v/v). The method was validated, obtaining adequate recovery and precision values. Limits of detection (LODs) and quantification (LOQs) were calculated, ranging from 2 to 150μgL(-1). Isoflavones were the predominant components present in the analyzed supplements with values higher than 93% of the total amount of phytochemicals in all cases. The aglycones (genistein, daidzein, glycitein and biochanin A) as well as their three conjugated forms, β-glucosides (genistin, daizin and glycitin) were detected and quantified, being daidzein the isoflavone detected at higher concentration in 8 out of 12 samples reported, with values ranging from 684 to 35,970mgkg(-1), whereas biochanin A was detected at very low concentrations, ranging from 18 to 50mgkg(-1). Moreover, other phytochemicals as flavones, flavonols, flavanones and phenolic acids were also detected and quantified. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Simultaneous quantification of amino acids and Amadori products in foods through ion-pairing liquid chromatography-high-resolution mass spectrometry.

    Science.gov (United States)

    Troise, Antonio Dario; Fiore, Alberto; Roviello, Giovanni; Monti, Simona Maria; Fogliano, Vincenzo

    2015-01-01

    The formation of the Amadori products (APs) is the first key step of Maillard reaction. Only few papers have dealt with simultaneous quantitation of amino acids and corresponding APs (1-amino-1-deoxy-2-ketose). Chromatographic separation of APs is affected by several drawbacks mainly related to their poor retention in conventional reversed phase separation. In this paper, a method for the simultaneous quantification of amino acids and their respective APs was developed combining high-resolution mass spectrometry with ion-pairing liquid chromatography. The limit of detection was 0.1 ng/mL for tryptophan, valine and arginine, while the limit of quantification ranged from 2 to 5 ng/mL according to the specific sensitivity of each analyte. The relative standard deviation % was lower than 10 % and the coefficient of correlation was higher than 0.99 for each calibration curve. The method was applied to milk, milk-based products, raw and processed tomato. Among the analyzed products, the most abundant amino acid was glutamic acid (16,646.89 ± 1,385.40 µg/g) and the most abundant AP was fructosyl-arginine in tomato puree (774.82 ± 10.01 µg/g). The easiness of sample preparation coupled to the analytical performances of the proposed method introduced the possibility to use the pattern of free amino acids and corresponding APs in the evaluation of the quality of raw food as well as the extent of thermal treatments in different food products.

  17. Combining a Deconvolution and a Universal Library Search Algorithm for the Nontarget Analysis of Data-Independent Acquisition Mode Liquid Chromatography-High-Resolution Mass Spectrometry Results.

    Science.gov (United States)

    Samanipour, Saer; Reid, Malcolm J; Bæk, Kine; Thomas, Kevin V

    2018-04-17

    Nontarget analysis is considered one of the most comprehensive tools for the identification of unknown compounds in a complex sample analyzed via liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS). Due to the complexity of the data generated via LC-HRMS, the data-dependent acquisition mode, which produces the MS 2 spectra of a limited number of the precursor ions, has been one of the most common approaches used during nontarget screening. However, data-independent acquisition mode produces highly complex spectra that require proper deconvolution and library search algorithms. We have developed a deconvolution algorithm and a universal library search algorithm (ULSA) for the analysis of complex spectra generated via data-independent acquisition. These algorithms were validated and tested using both semisynthetic and real environmental data. A total of 6000 randomly selected spectra from MassBank were introduced across the total ion chromatograms of 15 sludge extracts at three levels of background complexity for the validation of the algorithms via semisynthetic data. The deconvolution algorithm successfully extracted more than 60% of the added ions in the analytical signal for 95% of processed spectra (i.e., 3 complexity levels multiplied by 6000 spectra). The ULSA ranked the correct spectra among the top three for more than 95% of cases. We further tested the algorithms with 5 wastewater effluent extracts for 59 artificial unknown analytes (i.e., their presence or absence was confirmed via target analysis). These algorithms did not produce any cases of false identifications while correctly identifying ∼70% of the total inquiries. The implications, capabilities, and the limitations of both algorithms are further discussed.

  18. Determination of steroid hormones and their metabolite in several types of meat samples by ultra high performance liquid chromatography-Orbitrap high resolution mass spectrometry.

    Science.gov (United States)

    López-García, Marina; Romero-González, Roberto; Garrido Frenich, Antonia

    2018-03-09

    A new analytical method based on ultra-high performance liquid chromatography (UHPLC) coupled to Orbitrap high resolution mass spectrometry (Orbitrap-HRMS) has been developed for the determination of steroid hormones (hydrocortisone, cortisone, progesterone, prednisone, prednisolone, testosterone, melengesterol acetate, hydrocortisone-21-acetate, cortisone-21-acetate, testosterone propionate, 17α-methyltestosterone, 6α-methylprednisolone and medroxyprogesterone) and their metabolite (17α-hydroxyprogesterone) in three meat samples (chicken, pork and beef). Two different extraction approaches were tested (QuEChERS "quick, easy, cheap, effective, rugged and safe" and "dilute and shoot"), observing that the QuEChERS method provided the best results in terms of recovery. A clean-up step was applied comparing several sorbents, obtaining the best results when florisil and aluminum oxide were used. The optimized method was validated, obtaining suitable results for all validation parameters in the three meat matrices evaluated. Recovery values ranged from 70% to 103% (except for prednisone in beef samples), meanwhile repeatability and reproducibility were obtained at values lower than 18% and 21%, respectively. The limit of quantification (LOQ) was established for most of the compounds at 1.0 μg/kg, except for testosterone in chicken and hydrocortisone-21-acetate and cortisone-21-acetate in pork at 2.0 μg/kg. Decision limit (CCα) and detection capability (CCβ) values ranged from 1.0-2.7 μg/kg and 1.9-5.5 μg/kg, respectively, in the three matrices. Finally, thirty one meat samples were analyzed and two hormones, progesterone and hydrocortisone, were detected in a beef and pork sample at 1.7 and 2.8 μg/kg respectively. Copyright © 2018 Elsevier B.V. All rights reserved.

  19. Determination of copper and mercury in phosphate fertilizers employing direct solid sampling analysis and high resolution continuum source graphite furnace atomic absorption spectrometry

    Science.gov (United States)

    de Oliveira Souza, Sidnei; François, Luciane Luiza; Borges, Aline Rocha; Vale, Maria Goreti Rodrigues; Araujo, Rennan Geovanny Oliveira

    2015-12-01

    The present study proposes the determination of copper and mercury in phosphate fertilizers by direct solid sampling analysis (SS) employing high resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GF AAS). For Cu determination, two analytical lines were used: 327.3960 nm and 249.2146 nm. Hg determination was carried out on the line 253.6521 nm and 100 μg KMnO4 was used as chemical modifier. The optimal pyrolysis temperature for Cu determination was 1300 °C. Atomization temperatures for Cu and Hg were 2400 and 1100 °C, respectively. External calibration with aqueous standard solutions was adopted for both elements. The limits of quantification (LoQs) and characteristic mass (m0) obtained for Cu determination were 0.4 μg g- 1 and 1.12 ng, respectively, on line 249.2146 nm, and 64 μg g- 1 and 25 pg on 327.3960 nm. For mercury, LoQ and m0 were 4.8 ng g- 1 and 39 pg, respectively. The accuracy of the proposed methods was confirmed by the analysis of standard reference material (SRM) of Trace Elements in Multi-Nutrient Fertilizer (SRM NIST 695). The precision expressed as relative standard deviation (RSD), was better than 8.2% for Hg and 7.7% for the Cu (n = 5), considered satisfactory for microanalysis in solid sample. Four fertilizer samples acquired in commercial establishments in the city of Salvador, Bahia, Brazil, were analyzed. The optimized analytical methods were simple, fast, accurate, precise and free of spectral interferences for the determination of Cu and Hg in phosphate fertilizer samples by SS-HR-CS GF AAS, avoiding the dissolution of the sample, the use of harmful reagents and the generation of residues.

  20. Suspect screening of large numbers of emerging contaminants in environmental waters using artificial neural networks for chromatographic retention time prediction and high resolution mass spectrometry data analysis.

    Science.gov (United States)

    Bade, Richard; Bijlsma, Lubertus; Miller, Thomas H; Barron, Leon P; Sancho, Juan Vicente; Hernández, Felix

    2015-12-15

    The recent development of broad-scope high resolution mass spectrometry (HRMS) screening methods has resulted in a much improved capability for new compound identification in environmental samples. However, positive identifications at the ng/L concentration level rely on analytical reference standards for chromatographic retention time (tR) and mass spectral comparisons. Chromatographic tR prediction can play a role in increasing confidence in suspect screening efforts for new compounds in the environment, especially when standards are not available, but reliable methods are lacking. The current work focuses on the development of artificial neural networks (ANNs) for tR prediction in gradient reversed-phase liquid chromatography and applied along with HRMS data to suspect screening of wastewater and environmental surface water samples. Based on a compound tR dataset of >500 compounds, an optimized 4-layer back-propagation multi-layer perceptron model enabled predictions for 85% of all compounds to within 2min of their measured tR for training (n=344) and verification (n=100) datasets. To evaluate the ANN ability for generalization to new data, the model was further tested using 100 randomly selected compounds and revealed 95% prediction accuracy within the 2-minute elution interval. Given the increasing concern on the presence of drug metabolites and other transformation products (TPs) in the aquatic environment, the model was applied along with HRMS data for preliminary identification of pharmaceutically-related compounds in real samples. Examples of compounds where reference standards were subsequently acquired and later confirmed are also presented. To our knowledge, this work presents for the first time, the successful application of an accurate retention time predictor and HRMS data-mining using the largest number of compounds to preliminarily identify new or emerging contaminants in wastewater and surface waters. Copyright © 2015 Elsevier B.V. All rights

  1. Quantification of the fluorine containing drug 5-fluorouracil in cancer cells by GaF molecular absorption via high-resolution continuum source molecular absorption spectrometry

    International Nuclear Information System (INIS)

    Krüger, Magnus; Huang, Mao-Dong; Becker-Roß, Helmut; Florek, Stefan; Ott, Ingo; Gust, Ronald

    2012-01-01

    The development of high-resolution continuum source molecular absorption spectrometry made the quantification of fluorine feasible by measuring the molecular absorption as gallium monofluoride (GaF). Using this new technique, we developed on the example of 5-fluorouracil (5-FU) a graphite furnace method to quantify fluorine in organic molecules. The effect of 5-FU on the generation of the diatomic GaF molecule was investigated. The experimental conditions such as gallium nitrate amount, temperature program, interfering anions (represented as corresponding acids) and calibration for the determination of 5-FU in standard solution and in cellular matrix samples were investigated and optimized. The sample matrix showed no effect on the sensitivity of GaF molecular absorption. A simple calibration curve using an inorganic sodium fluoride solution can conveniently be used for the calibration. The described method is sensitive and the achievable limit of detection is 0.23 ng of 5-FU. In order to establish the concept of “fluorine as a probe in medicinal chemistry” an exemplary application was selected, in which the developed method was successfully demonstrated by performing cellular uptake studies of the 5-FU in human colon carcinoma cells. - Highlights: ► Development of HR-CS MAS for quantification of fluorine bound to organic molecules ► Measuring as molecular absorption of gallium monofluoride ► Quantification of organic-bound fluorine in biological material ► The concept of “fluorine as a probe in medicinal chemistry” could be established

  2. Quantification of the fluorine containing drug 5-fluorouracil in cancer cells by GaF molecular absorption via high-resolution continuum source molecular absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Krueger, Magnus [Freie Universitaet Berlin, Institut fuer Pharmazie, Pharmazeutische Chemie, Koenigin-Luise-Str. 2-4, 14195 Berlin (Germany); Huang, Mao-Dong; Becker-Ross, Helmut; Florek, Stefan [Leibniz Institut fuer Analytische Wissenschaften, ISAS-e.V., Department Berlin, Albert-Einstein-Str. 9, 12489 Berlin (Germany); Ott, Ingo [Technische Universitaet Carolo Wilhelmina zu Braunschweig, Institut fuer Medizinische und Pharmazeutische Chemie, Beethovenstr. 55, 38106 Braunschweig (Germany); Gust, Ronald, E-mail: ronald.gust@uibk.ac.at [Universitaet Innsbruck, Institut fuer Pharmazie, Pharmazeutische Chemie, Innrain 80/82, 6020 Innsbruck (Austria)

    2012-03-15

    The development of high-resolution continuum source molecular absorption spectrometry made the quantification of fluorine feasible by measuring the molecular absorption as gallium monofluoride (GaF). Using this new technique, we developed on the example of 5-fluorouracil (5-FU) a graphite furnace method to quantify fluorine in organic molecules. The effect of 5-FU on the generation of the diatomic GaF molecule was investigated. The experimental conditions such as gallium nitrate amount, temperature program, interfering anions (represented as corresponding acids) and calibration for the determination of 5-FU in standard solution and in cellular matrix samples were investigated and optimized. The sample matrix showed no effect on the sensitivity of GaF molecular absorption. A simple calibration curve using an inorganic sodium fluoride solution can conveniently be used for the calibration. The described method is sensitive and the achievable limit of detection is 0.23 ng of 5-FU. In order to establish the concept of 'fluorine as a probe in medicinal chemistry' an exemplary application was selected, in which the developed method was successfully demonstrated by performing cellular uptake studies of the 5-FU in human colon carcinoma cells. - Highlights: Black-Right-Pointing-Pointer Development of HR-CS MAS for quantification of fluorine bound to organic molecules Black-Right-Pointing-Pointer Measuring as molecular absorption of gallium monofluoride Black-Right-Pointing-Pointer Quantification of organic-bound fluorine in biological material Black-Right-Pointing-Pointer The concept of 'fluorine as a probe in medicinal chemistry' could be established.

  3. Identification and quantification of fumonisin A1, A2, and A3 in corn by high-resolution liquid chromatography-orbitrap mass spectrometry.

    Science.gov (United States)

    Tamura, Masayoshi; Mochizuki, Naoki; Nagatomi, Yasushi; Harayama, Koichi; Toriba, Akira; Hayakawa, Kazuichi

    2015-02-16

    Three compounds, hypothesized as fumonisin A1 (FA1), fumonisin A2 (FA2), and fumonisin A3 (FA3), were detected in a corn sample contaminated with mycotoxins by high-resolution liquid chromatography-Orbitrap mass spectrometry (LC-Orbitrap MS). One of them has been identified as FA1 synthesized by the acetylation of fumonisin B1 (FB1), and established a method for its quantification. Herein, we identified the two remaining compounds as FA2 and FA3, which were acetylated fumonisin B2 (FB2) and fumonisin B3 (FB3), respectively. Moreover, we examined a method for the simultaneous analysis of FA1, FA2, FA3, FB1, FB2, and FB3. The corn samples were prepared by extraction using a QuEChERS kit and purification using a multifunctional cartridge. The linearity, recovery, repeatability, limit of detection, and limit of quantification of the method were >0.99, 82.9%-104.6%, 3.7%-9.5%, 0.02-0.60 μg/kg, and 0.05-1.98 μg/kg, respectively. The simultaneous analysis of the six fumonisins revealed that FA1, FA2, and FA3 were present in all corn samples contaminated with FB1, FB2, and FB3. The results suggested that corn marketed for consumption can be considered as being contaminated with both the fumonisin B-series and with fumonisin A-series. This report presents the first identification and quantification of FA1, FA2, and FA3 in corn samples.

  4. Method validation for high resolution sector field inductively coupled plasma mass spectrometry determination of the emerging contaminants in the open ocean: Rare earth elements as a case study

    Science.gov (United States)

    Wysocka, Irena; Vassileva, Emilia

    2017-02-01

    Analytical procedure for the determination of fourteen rare earth elements (REEs) in the seawater samples has been developed and validated. The elements (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) at ultra-trace level were measured by high resolution sector field inductively coupled plasma mass spectrometry (HR ICP-SFMS) after off-line analytes pre-concentration and matrix separation. The sample pre-treatment was carried out by commercially available automated system seaFAST-pico™, which is a low-pressure ion chromatography technique, based on solid phase extraction principles. Efficient elimination of seawater matrix and up to 50-fold pre-concentration of REEs enabled their accurate and precise quantification at ng L- 1 level. A validation approach in line with the requirements of ISO/IEC 17025 standard and Eurachem guidelines were followed. With this in mind, selectivity, working range, linearity, recovery (from 92% to 102%), repeatability (1%-4%), intermediate precision (2%-6%), limits of detection (0.001-0.08 ng L- 1) were systematically assessed. The total uncertainty associated to each result was estimated and the main sources of uncertainty sorted out. All major contributions to the combined uncertainty of the obtained results were identified and propagated together, following the ISO/GUM guidelines. The relative expanded uncertainty was estimated at range from 10.4% to 11.6% (k = 2). Demonstration of traceability of measurement results was also presented. Due to the low limits of detection, this method enables the determination of ultra-low levels of REEs in the open seawater as well as small variations in their concentrations. The potential of the proposed analytical procedure, based on combination of seaFAST-pico™ for sample preparation and HR ICP-SFMS, was demonstrated by direct analysis of seawater form different regions of the world.

  5. [Determination of 11 mycotoxins in baked foods and raw materials by ultra performance liquid chromatography-quadrupole/electrostatic field orbitrap high-resolution mass spectrometry].

    Science.gov (United States)

    Li, Rong; He, Chunmei; Yang, Luqi; Wang, Yong; Zhang, Pengjie; Gao, Yongqing

    2017-08-08

    A method for the determination of 11 mycotoxins in baked foods and raw materials by ultra-high performance liquid chromatography-quadrupole/electrostatic field orbitrap high-resolution mass spectrometry (UPLC-HRMS) is reported in this paper. The samples were extracted with 20 mL 90% (v/v) acetonitrile aqueous solution containing 1% (v/v) formic acid, and the extracts were salted out by 2.0 g MgSO 4 and 0.5 g NaCl, cleaned up by 300 mg C18. The analytes were carried out on a CORTECS C18 column (100 mm×2.1 mm, 1.6 μ m) by gradient elution with 2 mmol/L ammonium acetate with 0.1% (v/v) formic acid aqueous solution and 2 mmol/L ammonium acetate methanol with 0.1% (v/v) formic acid. The results showed that the 11 mycotoxins had good linear relationships in their respective mass concentration ranges. The correlation coefficients were not less than 0.9960 and the limits of quantitation (LOQs) were from 0.15 to 20.00 μ g/kg. The recoveries of the 11 mycotoxins in bread ranged from 64.38% to 122.61% with the relative standard deviations (RSDs) from 1.52% to 12.99% at three spiked levels ( n =6). The method is demonstrated to be simple, fast, highly sensitive, reliable and it is effective to detect common mycotoxins in baked foods and raw materials.

  6. Determination of mercury in airborne particulate matter collected on glass fiber filters using high-resolution continuum source graphite furnace atomic absorption spectrometry and direct solid sampling

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Rennan G.O., E-mail: rgoa01@terra.com.br [Laboratorio de Quimica Analitica Ambiental, Departamento de Quimica, Universidade Federal de Sergipe, Campus Sao Cristovao, 49.100-000, Sao Cristovao, SE (Brazil); Departamento de Quimica, Universidade Federal de Santa Catarina, 88040-900, Florianopolis, SC (Brazil); Vignola, Fabiola; Castilho, Ivan N.B. [Departamento de Quimica, Universidade Federal de Santa Catarina, 88040-900, Florianopolis, SC (Brazil); Borges, Daniel L.G.; Welz, Bernhard [Departamento de Quimica, Universidade Federal de Santa Catarina, 88040-900, Florianopolis, SC (Brazil); Instituto Nacional de Ciencia e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, 40170-115 Salvador, BA (Brazil); Vale, Maria Goreti R. [Instituto Nacional de Ciencia e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, 40170-115 Salvador, BA (Brazil); Instituto de Quimica, Universidade Federal do Rio Grande do Sul, 91501-970 Porto Alegre, RS (Brazil); Smichowski, Patricia [Comision Nacional de Energia Atomica (CNEA) and Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Buenos Aires (Argentina); Ferreira, Sergio L.C. [Instituto Nacional de Ciencia e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, 40170-115 Salvador, BA (Brazil); Instituto de Quimica, Universidade Federal da Bahia, 40170-290, Salvador, BA (Brazil); Becker-Ross, Helmut [Leibniz-Institut fuer Analytische Wissenschaften-ISAS-e.V., Department Berlin, 12489 Berlin (Germany)

    2011-05-15

    A study has been undertaken to assess the capability of high-resolution continuum source graphite furnace atomic absorption spectrometry for the determination of mercury in airborne particulate matter (APM) collected on glass fiber filters using direct solid sampling. The main Hg absorption line at 253.652 nm was used for all determinations. The certified reference material NIST SRM 1648 (Urban Particulate Matter) was used to check the accuracy of the method, and good agreement was obtained between published and determined values. The characteristic mass was 22 pg Hg. The limit of detection (3{sigma}), based on ten atomizations of an unexposed filter, was 40 ng g{sup -1}, corresponding to 0.12 ng m{sup -3} in the air for a typical air volume of 1440 m{sup 3} collected within 24 h. The limit of quantification was 150 ng g{sup -1}, equivalent to 0.41 ng m{sup -3} in the air. The repeatability of measurements was better than 17% RSD (n = 5). Mercury concentrations found in filter samples loaded with APM collected in Buenos Aires, Argentina, were between < 40 ng g{sup -1} and 381 {+-} 24 ng g{sup -1}. These values correspond to a mercury concentration in the air between < 0.12 ng m{sup -3} and 1.47 {+-} 0.09 ng m{sup -3}. The proposed procedure was found to be simple, fast and reliable, and suitable as a screening procedure for the determination of mercury in APM samples.

  7. Liquid chromatography-high resolution mass spectrometry (LC-HRMS) determination of stimulants, anorectic drugs and phosphodiesterase 5 inhibitors (PDE5I) in food supplements.

    Science.gov (United States)

    Strano-Rossi, Sabina; Odoardi, Sara; Castrignanò, Erika; Serpelloni, Giovanni; Chiarotti, Marcello

    2015-03-15

    The paper describes a liquid chromatography/high resolution mass spectrometry LC/HRMS method for the simultaneous identification and quantification of stimulants (ephedrines, caffeine, anorectic drugs such as phentermine, phendimetrazine, phenmetrazine, fenfluramine, benfluorex, mephentermine, fencanfamine, sibutramine) and PDE5I (sildenafil, vardenafil and tadalafil) in food supplements using a benchtop Orbitrap mass spectrometer. The mass detector, with a nominal resolving power of 100,000 (FWHM at m/z 200), operated in full scan mode in ESI positive ionization mode. Analytes were identified by retention times, accurate masses and correspondence of experimental and calculated isotopic patterns. The limits of detection (LOD) obtained varied from 1 to 25 ng g(-1) and limits of quantification (LOQ) were 50 ng g(-1) for all compounds. The method was linear for all the analytes in the ranges from 50 to 2000 ng g(-1), giving correlation coefficients>0.99. Accuracy (intended as %E) and repeatability (% CV) were always lower than 15%. The method was applied to the analysis of 36 dietary supplements, revealing the presence of ephedrine and/or pseudoephedrine in four of them, caffeine in eight of them and sildenafil in four of them. In one case, ephedrine was not reported on the label of the dietary supplement, as well as for caffeine in other two cases. A further confirmation of the analytes identity in positive samples was obtained through in-source fragmentation and comparison of the obtained fragments and their relative abundances with those from certified standards. As the acquisition mode is full scan, it would be also possible to re-process a previously acquired datafile for the investigation of untargeted analytes. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Fast sequential multi-element determination of major and minor elements in environmental samples and drinking waters by high-resolution continuum source flame atomic absorption spectrometry.

    Science.gov (United States)

    Gómez-Nieto, Beatriz; Gismera, Ma Jesús; Sevilla, Ma Teresa; Procopio, Jesús R

    2015-01-07

    The fast sequential multi-element determination of 11 elements present at different concentration levels in environmental samples and drinking waters has been investigated using high-resolution continuum source flame atomic absorption spectrometry. The main lines for Cu (324.754 nm), Zn (213.857 nm), Cd (228.802 nm), Ni (232.003 nm) and Pb (217.001 nm), main and secondary absorption lines for Mn (279.482 and 279.827 nm), Fe (248.327, 248.514 and 302.064 nm) and Ca (422.673 and 239.856 nm), secondary lines with different sensitivities for Na (589.592 and 330.237 nm) and K (769.897 and 404.414 nm) and a secondary line for Mg (202.582 nm) have been chosen to perform the analysis. A flow injection system has been used for sample introduction so sample consumption has been reduced up to less than 1 mL per element, measured in triplicate. Furthermore, the use of multiplets for Fe and the side pixel registration approach for Mg have been studied in order to reduce sensitivity and extend the linear working range. The figures of merit have been calculated and the proposed method was applied to determine these elements in a pine needles reference material (SRM 1575a), drinking and natural waters and soil extracts. Recoveries of analytes added at different concentration levels to water samples and extracts of soils were within 88-115% interval. In this way, the fast sequential multi-element determination of major and minor elements can be carried out, in triplicate, with successful results without requiring additional dilutions of samples or several different strategies for sample preparation using about 8-9 mL of sample. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. High-resolution mass spectrometry of skin mucus for monitoring physiological impacts and contaminant biotransformation products in fathead minnows exposed to wastewater effluent.

    Science.gov (United States)

    Mosley, Jonathan D; Ekman, Drew R; Cavallin, Jenna E; Villeneuve, Daniel L; Ankley, Gerald T; Collette, Timothy W

    2018-03-01

    High-resolution mass spectrometry is advantageous for monitoring physiological impacts and contaminant biotransformation products in fish exposed to complex wastewater effluent. We evaluated this technique using skin mucus from male and female fathead minnows (Pimephales promelas) exposed to control water or treated wastewater effluent at 5, 20, and 100% levels for 21 d, using an on-site, flow-through system providing real-time exposure. Both sex-specific and non-sex-specific responses were observed in the mucus metabolome, the latter suggesting the induction of general compensatory pathways for xenobiotic exposures. Altogether, 85 statistically significant treatment-dependent metabolite changes were observed out of the 310 total endogenous metabolites that were detected (156 of the 310 were annotated). Partial least squares-regression models revealed strong covariances between the mucus metabolomes and up-regulated hepatic messenger ribonucleic acid (mRNA) transcripts reported previously for these same fish. These regression models suggest that mucus metabolomic changes reflected, in part, processes by which the fish biotransformed xenobiotics in the effluent. In keeping with this observation, we detected a phase II transformation product of bisphenol A in the skin mucus of male fish. Collectively, these findings demonstrate the utility of mucus as a minimally invasive matrix for simultaneously assessing exposures and effects of environmentally relevant mixtures of contaminants. Environ Toxicol Chem 2018;37:788-796. Published 2017 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America. Published 2017 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.

  10. ANALYSIS OF DIOXINS IN CONTAMINATED SOILS WITH THE CALUX AND CAFLUX BIOASSAYS, AN IMMUNOASSAY, AND GAS CHROMATOGRAPHY/HIGH-RESOLUTION MASS SPECTROMETRY

    Science.gov (United States)

    Nording, Malin; Denison, Michael S.; Baston, David; Persson, Ylva; Spinnel, Erik; Haglund, Peter

    2010-01-01

    The chemically activated luciferase expression assay, the chemically activated fluorescence expression assay, and the enzyme-linked immunosorbent assay (ELISA) are all bioanalytical methods that have been used for the detection and quantification of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs). However, no comparisons of the results obtained by these three methods have been published analyzing identical replicates of purified sample extracts. Therefore, we have evaluated the performance of each of these methods for analyzing PCDD/Fs in aliquots of extracts from aged-contaminated soil samples and compared the results with those obtained by gas chromatography/high-resolution mass spectrometry (GC/HRMS). The quantitative performance was assessed and the effects of sample purification and data interpretation on the quality of the bioassay results were investigated. Results from the bioanalytical techniques were, in principle, not significantly different from each other or from the GC/HRMS data (p = 0.05). Furthermore, properly used, all of the bioanalytical techniques examined were found to be sufficiently sensitive, selective, and accurate to be used in connection with soil remediation activities when aiming at the remediation goal recommended by the U.S. Environmental Protection Agency (i.e., < 1,000 pg toxic equivalency/g). However, a site-specific correction factor should be applied with the use of the ELISA to account for differences between the toxic equivalency factors and the ELISA cross-reactivities of the various PCDD/F congeners, which otherwise might significantly underestimate the PCDD/F content. PMID:17571676

  11. Identification and accurate quantification of structurally related peptide impurities in synthetic human C-peptide by liquid chromatography-high resolution mass spectrometry.

    Science.gov (United States)

    Li, Ming; Josephs, Ralf D; Daireaux, Adeline; Choteau, Tiphaine; Westwood, Steven; Wielgosz, Robert I; Li, Hongmei

    2018-06-04

    Peptides are an increasingly important group of biomarkers and pharmaceuticals. The accurate purity characterization of peptide calibrators is critical for the development of reference measurement systems for laboratory medicine and quality control of pharmaceuticals. The peptides used for these purposes are increasingly produced through peptide synthesis. Various approaches (for example mass balance, amino acid analysis, qNMR, and nitrogen determination) can be applied to accurately value assign the purity of peptide calibrators. However, all purity assessment approaches require a correction for structurally related peptide impurities in order to avoid biases. Liquid chromatography coupled to high resolution mass spectrometry (LC-hrMS) has become the key technique for the identification and accurate quantification of structurally related peptide impurities in intact peptide calibrator materials. In this study, LC-hrMS-based methods were developed and validated in-house for the identification and quantification of structurally related peptide impurities in a synthetic human C-peptide (hCP) material, which served as a study material for an international comparison looking at the competencies of laboratories to perform peptide purity mass fraction assignments. More than 65 impurities were identified, confirmed, and accurately quantified by using LC-hrMS. The total mass fraction of all structurally related peptide impurities in the hCP study material was estimated to be 83.3 mg/g with an associated expanded uncertainty of 3.0 mg/g (k = 2). The calibration hierarchy concept used for the quantification of individual impurities is described in detail. Graphical abstract ᅟ.

  12. Non-targeted, high resolution mass spectrometry strategy for simultaneous monitoring of xenobiotics and endogenous compounds in green sea turtles on the Great Barrier Reef.

    Science.gov (United States)

    Heffernan, Amy L; Gómez-Ramos, Maria M; Gaus, Caroline; Vijayasarathy, Soumini; Bell, Ian; Hof, Christine; Mueller, Jochen F; Gómez-Ramos, Maria J

    2017-12-01

    Chemical contamination poses a threat to ecosystem, biota and human health, and identifying these hazards is a complex challenge. Traditional hazard identification relies on a priori-defined targets of limited chemical scope, and is generally inappropriate for exploratory studies such as explaining toxicological effects in environmental systems. Here we present a non-target high resolution mass spectrometry environmental monitoring study with multivariate statistical analysis to simultaneously detect biomarkers of exposure (e.g. xenobiotics) and biomarkers of effect in whole turtle blood. Borrowing the concept from clinical chemistry, a case-control sampling approach was used to investigate the potential influence of xenobiotics of anthropogenic origin on free-ranging green sea turtles (Chelonia mydas) from a remote, offshore 'control' site; and two coastal 'case' sites influenced by urban/industrial and agricultural activities, respectively, on the Great Barrier Reef in North Queensland, Australia. Multiple biomarkers of exposure, including sulfonic acids (n=9), a carbamate insecticide metabolite, and other industrial chemicals; and five biomarkers of effect (lipid peroxidation products), were detected in case sites. Additionally, two endogenous biomarkers of neuroinflammation and oxidative stress were identified, and showed moderate-to-strong correlations with clinical measures of inflammation and liver dysfunction. Our data filtering strategy overcomes limitations of traditional a priori selection of target compounds, and adds to the limited environmental xenobiotic metabolomics literature. To our knowledge this is the first case-control study of xenobiotics in marine megafauna, and demonstrates the utility of green sea turtles to link internal and external exposure, to explain potential toxicological effects in environmental systems. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. In-Situ Sampling Analysis of a Jupiter Trojan Asteroid by High Resolution Mass Spectrometry in the Solar Power Sail Mission

    Science.gov (United States)

    Kebukawa, Y.; Aoki, J.; Ito, M.; Kawai, Y.; Okada, T.; Matsumoto, J.; Yano, H.; Yurimoto, H.; Terada, K.; Toyoda, M.; Yabuta, H.; Nakamura, R.; Cottin, H.; Grand, N.; Mori, O.

    2017-12-01

    The Solar Power Sail (SPS) mission is one of candidates for the upcoming strategic middle-class space exploration to demonstrate the first outer Solar System journey of Japan. The mission concept includes in-situ sampling analysis of the surface and subsurface (up to 1 m) materials of a Jupiter Trojan asteroid using high resolution mass spectrometry (HRMS). The candidates for the HRMS are multi-turn time-of-flight mass spectrometer (MULTUM) type and Cosmorbitrap type. We plan to analyze isotopic and elemental compositions of volatile materials from organic matter, hydrated minerals, and ice (if any), in order to understand origin and evolution of the Jupiter Trojan asteroids. It will provide insights into planet formation/migration theories, evolution and distribution of volatiles in the Solar System, and missing link between asteroids and comets on evolutional. The HRMS system allows to measure H, N, C, O isotopic compositions and elemental compositions of molecules prepared by various pre-MS procedures including stepwise heating up to 600ºC, gas chromatography (GC), and high-temperature pyrolysis with catalyst to decompose the samples into simple gaseous molecules (e.g., H2, CO, and N2) for isotopic ratio analysis. The required mass resolution should be at least 30,000 for analyzing isotopic ratios for simple gaseous molecules. For elemental compositions, mass accuracy of 10 ppm is required to determine elemental compositions for molecules with m/z up to 300 (as well as compound specific isotopic compositions for smaller molecules). Our planned analytical sequences consist of three runs for both surface and subsurface samples. In addition, `sniff mode' which simply introduces environmental gaseous molecules into a HRMS will be done by the system.

  14. Analysis of lipophilic marine biotoxins by liquid chromatography coupled with high-resolution mass spectrometry in seawater from the Catalan Coast.

    Science.gov (United States)

    Bosch-Orea, Cristina; Sanchís, Josep; Farré, Marinella; Barceló, Damià

    2017-09-01

    Marine biotoxins regularly occur along the coast, with several consequences for the environment as well as the food industry. Monitoring of these compounds in seawater is required to assure the safety of marine resources for human consumption, providing a means for forecasting shellfish contamination events. In this study, an analytical method was developed for the detection of ten lipophilic marine biotoxins in seawater: azaspiracids 1, 2, 3, 4 and 5, classified as azaspiracid shellfish poisoning toxins, and pectenotoxin 2, okadaic acid and the related dinophysistoxin 1, yessotoxin and homoyessotoxin, classified as diarrheic shellfish poisoning toxins. The method is based on the application of solid-liquid ultrasound-assisted extraction and solid-phase extraction, followed by high-performance liquid chromatography coupled with high-resolution mass spectrometry. The limits of detection of this method are in the range of nanograms per litre and picograms per litre for most of the compounds, and recoveries range from 20.5% to 97.2%. To validate the effectiveness of this method, 36 samples of surface water from open coastal areas and marinas located along the Catalan coast on the Mediterranean Sea were collected and analysed. Eighty-eight per cent of these samples exhibited okadaic acid in particulate and aqueous phases in concentrations ranging from 0.11 to 560 μg/g and from 2.1 to 1780 ng/L respectively. Samples from open coastal areas exhibited higher concentrations of okadaic acid in particulate material, whereas in samples collected in sportive ports, the particulate material exhibited lower levels than the aqueous phase. Graphical Abstract Biotoxins investigated in seawater of the Catalan coast.

  15. Prediction of collision cross section and retention time for broad scope screening in gradient reversed-phase liquid chromatography-ion mobility-high resolution accurate mass spectrometry.

    Science.gov (United States)

    Mollerup, Christian Brinch; Mardal, Marie; Dalsgaard, Petur Weihe; Linnet, Kristian; Barron, Leon Patrick

    2018-03-23

    Exact mass, retention time (RT), and collision cross section (CCS) are used as identification parameters in liquid chromatography coupled to ion mobility high resolution accurate mass spectrometry (LC-IM-HRMS). Targeted screening analyses are now more flexible and can be expanded for suspect and non-targeted screening. These allow for tentative identification of new compounds, and in-silico predicted reference values are used for improving confidence and filtering false-positive identifications. In this work, predictions of both RT and CCS values are performed with machine learning using artificial neural networks (ANNs). Prediction was based on molecular descriptors, 827 RTs, and 357 CCS values from pharmaceuticals, drugs of abuse, and their metabolites. ANN models for the prediction of RT or CCS separately were examined, and the potential to predict both from a single model was investigated for the first time. The optimized combined RT-CCS model was a four-layered multi-layer perceptron ANN, and the 95th prediction error percentiles were within 2 min RT error and 5% relative CCS error for the external validation set (n = 36) and the full RT-CCS dataset (n = 357). 88.6% (n = 733) of predicted RTs were within 2 min error for the full dataset. Overall, when using 2 min RT error and 5% relative CCS error, 91.9% (n = 328) of compounds were retained, while 99.4% (n = 355) were retained when using at least one of these thresholds. This combined prediction approach can therefore be useful for rapid suspect/non-targeted screening involving HRMS, and will support current workflows. Copyright © 2018 Elsevier B.V. All rights reserved.

  16. Ultrasound-assisted single-drop microextraction for the determination of cadmium in vegetable oils using high-resolution continuum source electrothermal atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Almeida, Jorge S.; Anunciação, Taiana A.; Brandão, Geovani C.; Dantas, Alailson F.; Lemos, Valfredo A.

    2015-01-01

    This work presents an ultrasound-assisted single-drop microextraction procedure for the determination of cadmium in vegetable oils using high-resolution continuum source electrothermal atomic absorption spectrometry. Some initial tests showed that the best extraction efficiency was obtained when using ultrasound instead of mechanical agitation, indicating that acoustic cavitation improved the extraction process. Nitric, hydrochloric and acetic acids were evaluated for use in the extraction process, and HNO 3 gave the best results. A two-level full-factorial design was applied to investigate the best conditions for the extraction of Cd from the oil samples. The influences of the sonication amplitude, time and temperature of the extraction were evaluated. The results of the design revealed that all of the variables had a significant effect on the experimental results. Afterward, a Box–Behnken design was applied to determine the optimum conditions for the determination of cadmium in vegetable oil samples. According to a multivariate study, the optimum conditions were as follows: sonication amplitude of 60%, extraction time of 15 min, extraction temperature of 46 °C and 0.1 mol L −1 HNO 3 as the extractor solution. Under optimized conditions, the developed method allows for the determination of Cd in oil samples with a limit of quantification of 7.0 ng kg −1 . Addition and recovery experiments were performed in vegetable oil samples to evaluate the accuracy of the method, and the recoveries obtained varied from 90% to 115%. The samples were also analyzed after the acid digestion procedure, and the paired t-test (95% confidence level) did not show significant differences from the proposed method. - Highlights: • The determination of cadmium in vegetable oils was developed using UA-SDME. • HR-CS ET-AAS was employed as a detection technique with direct drop sampling. • The procedure allowed for a reduction in the consumption of reagents and samples

  17. Application of Internal Standard Method for Several 3d-Transition Metallic Elements in Flame Atomic Absorption Spectrometry Using a Multi-wavelength High-resolution Spectrometer.

    Science.gov (United States)

    Toya, Yusuke; Itagaki, Toshiko; Wagatsuma, Kazuaki

    2017-01-01

    We investigated a simultaneous internal standard method in flame atomic absorption spectrometry (FAAS), in order to better the analytical precision of 3d-transition metals contained in steel materials. For this purpose, a new spectrometer system for FAAS, comprising a bright xenon lamp as the primary radiation source and a high-resolution Echelle monochromator, was employed to measure several absorption lines at a wavelength width of ca. 0.3 nm at the same time, which enables the absorbances of an analytical line and also an internal standard line to be estimated. In considering several criteria for selecting an internal standard element and the absorption line, it could be suggested that platinum-group elements: ruthenium, rhodium, or palladium, were suitable for an internal standard element to determine the 3d-transition metal elements, such as titanium, iron, and nickel, by measuring an appropriate pair of these absorption lines simultaneously. Several variances of the absorption signal, such as a variation in aspirated amounts of sample solution and a short-period drift of the primary light source, would be corrected and thus reduced, when the absorbance ratio of the analytical line to the internal standard line was measured. In Ti-Pd, Ni-Rh, and Fe-Ru systems chosen as typical test samples, the repeatability of the signal respnses was investigated with/without the internal standard method, resulting in better precision when the internal standard method was applied in the FAAS with a nitrous oxide-acetylene flame rather than an air-acetylene flame.

  18. Direct determination of chromium in infant formulas employing high-resolution continuum source electrothermal atomic absorption spectrometry and solid sample analysis.

    Science.gov (United States)

    Silva, Arlene S; Brandao, Geovani C; Matos, Geraldo D; Ferreira, Sergio L C

    2015-11-01

    The present work proposed an analytical method for the direct determination of chromium in infant formulas employing the high-resolution continuum source electrothermal atomic absorption spectrometry combined with the solid sample analysis (SS-HR-CS ET AAS). Sample masses up to 2.0mg were directly weighted on a solid sampling platform and introduced into the graphite tube. In order to minimize the formation of carbonaceous residues and to improve the contact of the modifier solution with the solid sample, a volume of 10 µL of a solution containing 6% (v/v) H2O2, 20% (v/v) ethanol and 1% (v/v) HNO3 was added. The pyrolysis and atomization temperatures established were 1600 and 2400 °C, respectively, using magnesium as chemical modifier. The calibration technique was evaluated by comparing the slopes of calibration curves established using aqueous and solid standards. This test revealed that chromium can be determined employing the external calibration technique using aqueous standards. Under these conditions, the method developed allows the direct determination of chromium with limit of quantification of 11.5 ng g(-1), precision expressed as relative standard deviation (RSD) in the range of 4.0-17.9% (n=3) and a characteristic mass of 1.2 pg of chromium. The accuracy was confirmed by analysis of a certified reference material of tomato leaves furnished by National Institute of Standards and Technology. The method proposed was applied for the determination of chromium in five different infant formula samples. The chromium content found varied in the range of 33.9-58.1 ng g(-1) (n=3). These samples were also analyzed employing ICP-MS. A statistical test demonstrated that there is no significant difference between the results found by two methods. The chromium concentrations achieved are lower than the maximum limit permissible for chromium in foods by Brazilian Legislation. Copyright © 2015. Published by Elsevier B.V.

  19. Determination of Pb (Lead, Cd (Cadmium, Cr (Chromium, Cu (Copper, and Ni (Nickel in Chinese tea with high-resolution continuum source graphite furnace atomic absorption spectrometry

    Directory of Open Access Journals (Sweden)

    Wen-Si Zhong

    2016-01-01

    Full Text Available The contents of lead, cadmium, chromium, copper, and nickel were determined in 25 tea samples from China, including green, yellow, white, oolong, black, Pu'er, and jasmine tea products, using high-resolution continuum source graphite furnace atomic absorption spectrometry. The methods used for sample preparation, digestion, and quantificational analysis were established, generating satisfactory analytical precisions (represented by relative standard deviations ranging from 0.6% to 2.5% and recoveries (98.91–101.32%. The lead contents in tea leaves were 0.48–10.57 mg/kg, and 80% of these values were below the maximum values stated by the guidelines in China. The contents of cadmium and chromium ranged from 0.01 mg/kg to 0.39 mg/kg and from 0.27 mg/kg to 2.45 mg/kg, respectively, remaining in compliance with the limits stipulated by China's Ministry of Agriculture. The copper contents were 7.73–63.71 mg/kg; only 64% of these values complied with the standards stipulated by the Ministry of Agriculture. The nickel contents ranged from 2.70 mg/kg to 13.41 mg/kg. Consequently, more attention must be paid to the risks of heavy metal contamination in tea. The quantitative method established in this work lays a foundation for preventing heavy metal toxicity in human from drinking tea and will help establish regulations to control the contents of heavy metals in tea.

  20. Ultrasound-assisted single-drop microextraction for the determination of cadmium in vegetable oils using high-resolution continuum source electrothermal atomic absorption spectrometry

    Science.gov (United States)

    Almeida, Jorge S.; Anunciação, Taiana A.; Brandão, Geovani C.; Dantas, Alailson F.; Lemos, Valfredo A.; Teixeira, Leonardo S. G.

    2015-05-01

    This work presents an ultrasound-assisted single-drop microextraction procedure for the determination of cadmium in vegetable oils using high-resolution continuum source electrothermal atomic absorption spectrometry. Some initial tests showed that the best extraction efficiency was obtained when using ultrasound instead of mechanical agitation, indicating that acoustic cavitation improved the extraction process. Nitric, hydrochloric and acetic acids were evaluated for use in the extraction process, and HNO3 gave the best results. A two-level full-factorial design was applied to investigate the best conditions for the extraction of Cd from the oil samples. The influences of the sonication amplitude, time and temperature of the extraction were evaluated. The results of the design revealed that all of the variables had a significant effect on the experimental results. Afterward, a Box-Behnken design was applied to determine the optimum conditions for the determination of cadmium in vegetable oil samples. According to a multivariate study, the optimum conditions were as follows: sonication amplitude of 60%, extraction time of 15 min, extraction temperature of 46 °C and 0.1 mol L- 1 HNO3 as the extractor solution. Under optimized conditions, the developed method allows for the determination of Cd in oil samples with a limit of quantification of 7.0 ng kg- 1. Addition and recovery experiments were performed in vegetable oil samples to evaluate the accuracy of the method, and the recoveries obtained varied from 90% to 115%. The samples were also analyzed after the acid digestion procedure, and the paired t-test (95% confidence level) did not show significant differences from the proposed method.

  1. Ultrasound-assisted single-drop microextraction for the determination of cadmium in vegetable oils using high-resolution continuum source electrothermal atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Jorge S.; Anunciação, Taiana A. [Departamento de Química Analítica, Instituto de Química, Universidade Federal da Bahia, Campus Universitário de Ondina, Salvador, Bahia 40170-280 (Brazil); Brandão, Geovani C. [Departamento de Química Analítica, Instituto de Química, Universidade Federal da Bahia, Campus Universitário de Ondina, Salvador, Bahia 40170-280 (Brazil); INCT de Energia e Ambiente, Instituto de Química, Universidade Federal da Bahia, Campus Universitário de Ondina, Salvador, Bahia 40170-280 (Brazil); Dantas, Alailson F. [Departamento de Química Analítica, Instituto de Química, Universidade Federal da Bahia, Campus Universitário de Ondina, Salvador, Bahia 40170-280 (Brazil); Lemos, Valfredo A. [Laboratório de Química Analítica (LQA), Universidade Estadual do Sudoeste da Bahia, Campus de Jequié, Jequié, Bahia 45506-191 (Brazil); and others

    2015-05-01

    This work presents an ultrasound-assisted single-drop microextraction procedure for the determination of cadmium in vegetable oils using high-resolution continuum source electrothermal atomic absorption spectrometry. Some initial tests showed that the best extraction efficiency was obtained when using ultrasound instead of mechanical agitation, indicating that acoustic cavitation improved the extraction process. Nitric, hydrochloric and acetic acids were evaluated for use in the extraction process, and HNO{sub 3} gave the best results. A two-level full-factorial design was applied to investigate the best conditions for the extraction of Cd from the oil samples. The influences of the sonication amplitude, time and temperature of the extraction were evaluated. The results of the design revealed that all of the variables had a significant effect on the experimental results. Afterward, a Box–Behnken design was applied to determine the optimum conditions for the determination of cadmium in vegetable oil samples. According to a multivariate study, the optimum conditions were as follows: sonication amplitude of 60%, extraction time of 15 min, extraction temperature of 46 °C and 0.1 mol L{sup −1} HNO{sub 3} as the extractor solution. Under optimized conditions, the developed method allows for the determination of Cd in oil samples with a limit of quantification of 7.0 ng kg{sup −1}. Addition and recovery experiments were performed in vegetable oil samples to evaluate the accuracy of the method, and the recoveries obtained varied from 90% to 115%. The samples were also analyzed after the acid digestion procedure, and the paired t-test (95% confidence level) did not show significant differences from the proposed method. - Highlights: • The determination of cadmium in vegetable oils was developed using UA-SDME. • HR-CS ET-AAS was employed as a detection technique with direct drop sampling. • The procedure allowed for a reduction in the consumption of reagents and

  2. Mass defect filtering-oriented classification and precursor ions list-triggered high-resolution mass spectrometry analysis for the discovery of indole alkaloids from Uncaria sinensis.

    Science.gov (United States)

    Pan, Huiqin; Yang, Wenzhi; Yao, Changliang; Shen, Yao; Zhang, Yibei; Shi, Xiaojian; Yao, Shuai; Wu, Wanying; Guo, Dean

    2017-09-22

    Discovery of new natural compounds is becoming increasingly challenging because of the interference from those known and abundant components. The aim of this study is to report a dereplication strategy, by integrating mass defect filtering (MDF)-oriented novelty classification and precursor ions list (PIL)-triggered high-resolution mass spectrometry analysis, and to validate it by discovering new indole alkaloids from the medicinal herb Uncaria sinensis. Rapid chromatographic separation was achieved on a Kinetex ® EVO C18 column (<16min). An in-house MDF algorithm, developed based on the informed phytochemistry information and molecular design, could more exactly screen the target alkaloids and divide them into three novelty levels: Known (KN), Unknown-but-Predicted (UP), and Unexpected (UN). A hybrid data acquisition method, namely PIL-triggered collision-induced dissociation-MS 2 and high-energy C-trap dissociation-MS 3 with dynamic exclusion on a linear ion trap/Orbitrap mass spectrometer, facilitated the acquisition of diverse product ions sufficient for the structural elucidation of both indole alkaloids and the N-oxides. Ultimately, 158 potentially new alkaloids, including 10 UP and 108 UN, were rapidly characterized from the stem, leaf, and flower of U. sinensis. Two new alkaloid compounds thereof were successfully isolated and identified by 1D and 2D NMR analyses. The varied ring E and novel alkaloid-acylquinic acid conjugates were first reported from the whole Uncaria genus. Conclusively, it is a practical chemical dereplication strategy that can enhance the efficiency and has the potential to be a routine approach for the discovery of new natural compounds. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Software-aided approach to investigate peptide structure and metabolic susceptibility of amide bonds in peptide drugs based on high resolution mass spectrometry.

    Directory of Open Access Journals (Sweden)

    Tatiana Radchenko

    Full Text Available Interest in using peptide molecules as therapeutic agents due to high selectivity and efficacy is increasing within the pharmaceutical industry. However, most peptide-derived drugs cannot be administered orally because of low bioavailability and instability in the gastrointestinal tract due to protease activity. Therefore, structural modifications peptides are required to improve their stability. For this purpose, several in-silico software tools have been developed such as PeptideCutter or PoPS, which aim to predict peptide cleavage sites for different proteases. Moreover, several databases exist where this information is collected and stored from public sources such as MEROPS and ExPASy ENZYME databases. These tools can help design a peptide drug with increased stability against proteolysis, though they are limited to natural amino acids or cannot process cyclic peptides, for example. We worked to develop a new methodology to analyze peptide structure and amide bond metabolic stability based on the peptide structure (linear/cyclic, natural/unnatural amino acids. This approach used liquid chromatography / high resolution, mass spectrometry to obtain the analytical data from in vitro incubations. We collected experimental data for a set (linear/cyclic, natural/unnatural amino acids of fourteen peptide drugs and four substrate peptides incubated with different proteolytic media: trypsin, chymotrypsin, pepsin, pancreatic elastase, dipeptidyl peptidase-4 and neprilysin. Mass spectrometry data was analyzed to find metabolites and determine their structures, then all the results were stored in a chemically aware manner, which allows us to compute the peptide bond susceptibility by using a frequency analysis of the metabolic-liable bonds. In total 132 metabolites were found from the various in vitro conditions tested resulting in 77 distinct cleavage sites. The most frequent observed cleavage sites agreed with those reported in the literature. The

  4. Strontium mono-chloride — A new molecule for the determination of chlorine using high-resolution graphite furnace molecular absorption spectrometry and direct solid sample analysis

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Éderson R. [Departamento de Química, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Welz, Bernhard, E-mail: w.bernardo@terra.com.br [Departamento de Química, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Instituto Nacional de Ciência e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, 40170-115 Salvador, BA (Brazil); Lopez, Alfredo H.D.; Gois, Jefferson S. de; Caramori, Giovanni F. [Departamento de Química, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Borges, Daniel L.G.; Carasek, Eduardo [Departamento de Química, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Instituto Nacional de Ciência e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, 40170-115 Salvador, BA (Brazil); Andrade, Jailson B. de [Instituto Nacional de Ciência e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, 40170-115 Salvador, BA (Brazil)

    2014-12-01

    A new method has been developed for the determination of chlorine in biological reference materials using high-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS GF MAS) of the strontium mono-chloride (SrCl) molecule and direct solid sample analysis. The use of the SrCl molecule for high-temperature MAS was not described up to now in the literature. Preliminary time-dependent density functional theory calculations of the SrCl structure were carried out in order to obtain reasonable estimates of the absorption spectrum of the target molecule. The calculations, which were carried out at BHandHLyp/def2-QZVP level of theory, proved a very accurate and inexpensive way to get information about the spectrum of the SrCl molecule, which enabled us to perform the Cl determination with good sensitivity and specificity. The molecular absorption of the SrCl molecule has been measured using the wavelength at 635.862 nm, and zirconium and palladium have been evaluated as the chemical modifiers in order to increase the sensitivity of the gaseous SrCl molecule generated in the graphite furnace. The pyrolysis and vaporization temperatures were 600 °C and 2300 °C, respectively. Accuracy and precision of the method have been evaluated using biological certified reference materials of both animal and plant origins, showing good agreement with the informed and certified values. Limit of detection and characteristic mass were 1.0 and 2.2 ng, respectively. The results found using HR-CS GF MAS were in agreement (95% confidence level) compared to those obtained by electrothermal vaporization-inductively coupled plasma mass spectrometry. - Highlights: • The spectrum of the SrCl molecule was calculated on a theoretical basis and found very close to the predicted wavelength. • It is the first time that the spectrum of the SrCl molecule is described and used analytically for the determination of Cl. • No spectral interferences were observed as the

  5. Investigation of spectral interferences in the determination of lead in fertilizers and limestone samples using high-resolution continuum source graphite furnace atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Borges, Aline R. [Instituto de Química, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, 91501-970 Porto Alegre, RS (Brazil); Instituto Nacional de Ciência e Tecnologia do CNPq — INCT de Energia e Ambiente, Universidade Federal da Bahia, Salvador, BA (Brazil); Becker, Emilene M.; François, Luciane L.; Jesus, Alexandre de [Instituto de Química, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, 91501-970 Porto Alegre, RS (Brazil); Vale, Maria Goreti R. [Instituto de Química, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, 91501-970 Porto Alegre, RS (Brazil); Instituto Nacional de Ciência e Tecnologia do CNPq — INCT de Energia e Ambiente, Universidade Federal da Bahia, Salvador, BA (Brazil); Welz, Bernhard [Instituto Nacional de Ciência e Tecnologia do CNPq — INCT de Energia e Ambiente, Universidade Federal da Bahia, Salvador, BA (Brazil); Departamento de Química, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Dessuy, Morgana B., E-mail: mbdessuy@ufrgs.br [Instituto de Química, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, 91501-970 Porto Alegre, RS (Brazil); Andrade, Jailson B. de [Instituto Nacional de Ciência e Tecnologia do CNPq — INCT de Energia e Ambiente, Universidade Federal da Bahia, Salvador, BA (Brazil)

    2014-11-01

    In the present work, spectral interferences on the determination of lead in fertilizer and limestone samples were investigated using high-resolution continuum source graphite furnace atomic absorption spectrometry at the main analytical lines: 217.001 and 283.306 nm. For these investigations, samples were introduced into the furnace as slurry together with a mixture of Pd and Mg as chemical modifier. Spectral interferences were observed for some samples at both analytical lines. In order to verify whether a wet digestion procedure would avoid these interferences, a reference method for wet digestion of fertilizers was employed as an alternative sample preparation procedure. However, the same interferences were also observed in the digested samples. In order to identify and eliminate the fine-structured background using a least-squares background correction, reference spectra were generated using the combination of different species. The use of the latter technique allowed the elimination of spectral interferences for most of the investigated samples, making possible the determination of lead in fertilizer and limestone samples free of interferences. The best results were found using a reference spectrum of NH{sub 4}H{sub 2}PO{sub 4} at 217.001 nm, and a mixture of H{sub 2}SO{sub 4} + Ca and HNO{sub 3} + Ca at the 283.306 nm line. The accuracy of the method was evaluated using a certified reference material “Trace Elements in Multi-Nutrient Fertilizer”. Similar results were obtained using line source graphite furnace atomic absorption spectrometry with Zeeman-effect background correction, indicating that the latter technique was also capable to correct the spectral interferences, at least in part. - Highlights: • Spectral interferences on the determination of lead in fertilizers and limestone. • The analytical lines at 217.001 nm and 283.306 nm using HR-CS GF AAS. • Various combinations of compounds were used to create reference spectra. • LSBC

  6. Simultaneous determination of cadmium, iron and tin in canned foods using high-resolution continuum source graphite furnace atomic absorption spectrometry.

    Science.gov (United States)

    Leao, Danilo J; Junior, Mario M S; Brandao, Geovani C; Ferreira, Sergio L C

    2016-06-01

    A method was established to simultaneously determine cadmium, iron and tin in canned-food samples using high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GF AAS). The quantification step has been performed using the primary line (228.802nm) for cadmium and the adjacent secondary lines (228.725nm and 228.668nm) for iron and tin, respectively. The selected chemical modifier was an acid solution that contained a mixture of 0.1% (w/v) Pd and 0.05% (w/v) Mg. The absorbance signals were measured based on the peak area using 3 pixels for cadmium and 5 pixels for iron and tin. Under these conditions, cadmium, iron and tin have been determined in canned-food samples using the external calibration technique based on aqueous standards, where the limits of quantification were 2.10ngg(-1) for cadmium, 1.95mgkg(-1) for iron and 3.00mgkg(-1) for tin, and the characteristic masses were 1.0pg for cadmium, 0.9ng for iron and 1.1ng for tin. The precision was evaluated using two solutions of each metal ion, and the results, which were expressed as the relative standard deviation (RSD%), were 3.4-6.8%. The method accuracy for cadmium and iron was confirmed by analyzing a certified reference material of apple leaves (NIST 1515), which was supplied by NIST. However, for tin, the accuracy was confirmed by comparing the results of the proposed method and another analytical technique (inductively coupled plasma optical emission spectrometry). The proposed procedure was applied to determine cadmium, iron and tin in canned samples of peeled tomato and sardine. Eleven samples were analyzed, and the analyte concentrations were 3.57-62.9ngg(-1), 2.68-31.48mgkg(-1) and 4.06-122.0mgkg(-1) for cadmium, iron and tin, respectively. In all analyzed samples, the cadmium and tin contents were lower than the permissible maximum levels for these metals in canned foods in the Brazilian legislation. Copyright © 2016. Published by Elsevier