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Sample records for chromatographic-mass spectrometric studies

  1. Liquid chromatographic-mass spectrometric method for ...

    African Journals Online (AJOL)

    Tropical Journal of Pharmaceutical Research ... Purpose: To develop and validate a simple, efficient and reliable Liquid chromatographic-mass spectrometric (LC-MS/MS) method for the quantitative determination of two dermatological drugs, ... By Country · List All Titles · Free To Read Titles This Journal is Open Access.

  2. INTERLABORATORY STUDY OF A THERMOSPRAY-LIQUID CHROMATOGRAPHIC/MASS SPECTROMETRIC METHOD FOR SELECTED N-METHYL CARBAMATES, N-METHYL CARBAMOYLOXIMES, AND SUBSTITUTED UREA PESTICIDES

    Science.gov (United States)

    A thermospray-liquid chromatographic/mass spectrometric (TS-LC/MS) method was evaluated in an interlaboratory study for determining 3 N-methyl carbamates (bendiocarb, carbaryl, and carbofuran), 3-N-methyl carbamoyloximes (aldicarb, methomyl, and oxamyl), 2 substituted urea pestic...

  3. Chromatographic-mass spectrometric analysis of ethanol extract of ...

    African Journals Online (AJOL)

    Purpose: This study analyzes the chemical composition of ethanol root extracts of Maesa perlaria var. formosana by .... obtained over a scanning range of 50 to 550 amu at 2 scans/s. .... 142.53 (2,2,6-Trimethyl-bicyclo[4.1.0]hept-1-yl)-methanol.

  4. Gas Chromatographic Mass Spectrometric Determination of Myo-inositol in Humans Utilizing a Deuterated Internal Standard

    DEFF Research Database (Denmark)

    Andersen, Jan Rud; Larsen, Elfinn; Harbo, Helge

    1982-01-01

    The isotopic dilution technique was used for determining the content of myo-inositol in human urine, plasma and haemolysed erythrocyte samples. A deuterated myo-inositol, synthesized from inosose-2 by base-catalysed exchange of hydrogens by deuterium, followed by reduction of the inosose with 2H2......, was added as internal standard to the samples at an early stage in the analytical procedure. After separation and derivatization to the hexa-acetate, the gas chromatographic mass spectrometric analysis was carried out. A 25 m fused silica capillary column coated with methyl silicone was used, and the ions...... selected for monitoring were m/z 210 and m/z 214, which are characteristic and abundant fragment ions from unlabelled and hexadeuterated myo-inositolhexa-acetate, respectively. Calibration curves from water, urine, plasma and haemolysed erythrocytes show parallel, linear responses in the ratio between...

  5. The gas-chromatographic and gas-chromatographic-mass-spectrometric identification of halogen-containing organic compounds

    Science.gov (United States)

    Gidaspov, B. V.; Zenkevich, I. G.; Rodin, A. A.

    1989-09-01

    The problem of identifying halogen-containing organic compounds in their gas-chromatographic and gas-chromatographic-mass-spectrometric (GC-MS) determination in different materials has been examined. Particular attention has been paid not to the complete characterisation of methods for carrying out this analysis but to the most important problem of increasing the selectivity at the stages of sampling, separation, and interpretation of the gas-chromatographic and GC-MS information. The bibliography contains 292 references.

  6. High performance liquid chromatographic-mass spectrometric assay for the quantitation of BMS-204352 in dog K(3)EDTA plasma.

    Science.gov (United States)

    Yao, Ming; Mantha, Subbarao; Shah, Vinod R; Vachharajani, Nimish N; Arnold, Mark E; Pursley, Janice M; Srinivas, Nuggehally R

    2002-05-01

    A high performance liquid chromatographic-mass spectrometric (LC/MS) assay was developed and validated for the determination of BMS-204352 in dog K(3)EDTA plasma. A 0.5 mL aliquot of control plasma was spiked with BMS-204352 and internal standard (IS) and buffered with 1 mL of 5 mM ammonium acetate. The mixture was then extracted with 3 mL of toluene. After separation and evaporation of the organic phase to dryness using nitrogen at 40 degrees C, the residue was reconstituted in the mobile phase and 25 microL of the sample were injected onto a Hypersil C(18) column (2 x 50 mm; 3 microm) at a flow rate of 0.5 mL/min. The mobile phase was consisted of two solvent mixtures (A and B). Solvent A was composed of 5 mM ammonium acetate and 0.1% triethylamine in 75:25 v/v water:methanol, pH adjusted to 5.5 with glacial acetic acid, and solvent B was 5 mM ammonium acetate in methanol. A linear gradient system was used to elute the analytes. The mass spectrometer was programmed to admit the de-protonated molecules at m/z 352.7 (IS) and m/z 357.9 (BMS-204352). Standard curves of BMS-204352 were linear (r(2) > or = 0.998) over the concentration range of 0.5-1000 ng/mL. The mean predicted quality control (QC) concentrations deviated less than 5.1% from the corresponding nominal values (ie 4, 80, 400 and 2000 ng/mL); the within- and between-assay precision of the assay were within 5.5% relative standard deviation. Stability of BMS-204352 was confirmed after at least three freeze/thaw cycles and BMS-204532 was stable in dog plasma when stored frozen at or below -20 degrees C for at least 16 weeks in spiked QC samples and for at least 4 1/2 weeks for in vivo study samples. BMS-204352 and IS were stable in the injection solvent at room temperature for at least 24 h. The assay was applied to delineate the pharmacokinetic disposition of BMS-204352 in dogs following a single intravenous dose administration. In conclusion, the assay is accurate, precise, specific, sensitive and

  7. Gas chromatographic/mass spectrometric determination of carbon isotope composition in unpurified samples: methamphetamine example.

    Science.gov (United States)

    Low, I A; Liu, R H; Legendre, M G; Piotrowski, E G; Furner, R L

    1986-10-01

    A gas chromatograph/quadrupole mass spectrometer system, operated in electron impact/selected ion monitoring mode, is used to determine the intensity ratio of the m/z 59 and the m/z 58 ions of the [C3H8N]+ fragment derived from methamphetamine samples synthesized with varying amounts of 13C-labeled methylamine. Crude products are introduced into the gas chromatograph without prior cleanup. The ratios measured were in excellent agreement with those calculated. A change in 0.25% use of 13C-methylamine is sufficient for product differentiation. The feasibility of using isotope labeling and subsequent mass spectrometric isotope ratio measurement as the basis of a compound tracing mechanism is discussed. Specifically, if methamphetamine samples manufactured from legal sources are asked to incorporate distinct 13C compositions, their sources can be traced when samples are diverted into illegal channels. Samples derived from illicit preparations can also be traced if the manufacturers of a precursor (methylamine in this case) incorporate distinct 13C compositions in their products.

  8. Gas chromatographic-mass spectrometric characterisation of plant gums in samples from painted works of art.

    Science.gov (United States)

    Bonaduce, Ilaria; Brecoulaki, Hariclia; Colombini, Maria Perla; Lluveras, Anna; Restivo, Vincenzo; Ribechini, Erika

    2007-12-21

    This paper presents an analytical GC-MS procedure to study the chemical composition of plant gums, determining aldoses and uronic acids in one step. The procedure is based on the silylation of aldoses and uronic acids, released from plant gums by microwave assisted hydrolysis, and previously converted into the corresponding diethyl-dithioacetals and diethyl-dithioacetal lactones. Using this method only one peak for each compound is obtained, thus providing simple and highly reproducible chromatograms. The analytical procedure was optimised using reference samples of raw plant gums (arabic, karaya, ghatti, guar, locust bean and tragacanth, cherry, plum and peach gums), commercial watercolours and paint layers prepared according to ancient recipes at the Opificio delle Pietre Dure of Florence (Italy). To identify gum media in samples of unknown composition, a decisional schema for the gum identification and the principal component analysis of the relative sugar percentage contents were employed. The procedure was used to study samples collected from wall paintings from Macedonian tombs (4th-3rd centuries bc) and from the Mycenaean "Palace of Nestor" (13th century bc) in Pylos, Greece. The presence of carbohydrates was ascertained and plant gum binders (fruit and a mixture of tragacanth and fruit tree gums) were identified in some of the samples.

  9. Gas chromatographic--mass spectrometric quantitation of 16, 16-dimethyl-trans-delta 2-PGE1

    Energy Technology Data Exchange (ETDEWEB)

    Dimov, V.; Green, K.; Bygdeman, M.; Konishi, Y.; Imaki, K.; Hayashi, M.

    1983-02-01

    Di-deuterated and di-tritiated 16,16-dimethyl-trans-delta 2-PGE1 has been synthesized and used for development of a GC-MS method for quantitation of corresponding unlabelled drug in patient plasma. Although these carrier/internal standard molecules only contain 2 deuterium atoms the lower limit of detection at each injection is as low as about 40 pg. The maximum plasma levels of this drug following administration of vaginal suppositories used in clinical studies (1 mg 16,16-dimethyl-trans-delta 2-PGE1 methyl ester in 0.8 g Witepsol S-52) were 100-350 pg/ml i.e. in the same order of magnitude as earlier seen for 16,16-dimethyl-PGE2.

  10. Gas chromatographic--mass spectrometric quantitation of 16, 16-dimethyl-trans-delta 2-PGE1

    International Nuclear Information System (INIS)

    Dimov, V.; Green, K.; Bygdeman, M.; Konishi, Y.; Imaki, K.; Hayashi, M.

    1983-01-01

    Di-deuterated and di-tritiated 16,16-dimethyl-trans-delta 2-PGE1 has been synthesized and used for development of a GC-MS method for quantitation of corresponding unlabelled drug in patient plasma. Although these carrier/internal standard molecules only contain 2 deuterium atoms the lower limit of detection at each injection is as low as about 40 pg. The maximum plasma levels of this drug following administration of vaginal suppositories used in clinical studies (1 mg 16,16-dimethyl-trans-delta 2-PGE1 methyl ester in 0.8 g Witepsol S-52) were 100-350 pg/ml i.e. in the same order of magnitude as earlier seen for 16,16-dimethyl-PGE2

  11. Comparison of radioimmunoassay and gas chromatographic mass spectrometric assay for d-amphetamine

    International Nuclear Information System (INIS)

    Powers, K.H.; Ebert, M.H.

    1979-01-01

    Quantification of low levels of psychotropic drugs (10 -7 to 10 -9 g ml -1 ) in small volumes of plasma requires sensitive and accurate methods. Validation of these methods is best achieved by comparing results obtained using several techniques. In this study, amphetamine levels in plasma were measured using gas chromatography mass spectrometry and radioimmunoassay. Correlation of the results obtained by the two methods was found to be positive and high (R = 0.9822). The average coefficient of variation between assays for gas chromatography mass spectrometry was 5.8% and for radioimmunoassay was 12.3%, while the average coefficient of variation within assays for gas chromatography mass spectrometry was 4.9% and for radioimmunoassay 6.9%. Although gas chromatography mass spectrometry was 1.9 times more sensitive than radioimmunoassay, for most purposes, the convenience of the radioimmunoassay method outweighs the technical superiority of gas chromatography mass spectrometry. (author)

  12. Gas chromatographic/mass spectrometric and microbiological analyses on irradiated chicken

    Science.gov (United States)

    Parlato, A.; Calderaro, E.; Bartolotta, A.; D'Oca, M. C.; Giuffrida, S. A.; Brai, M.; Tranchina, L.; Agozzino, P.; Avellone, G.; Ferrugia, M.; Di Noto, A. M.; Caracappa, S.

    2007-08-01

    Ionizing radiation is widely used as treatment technique for food preservation. It involves among others reduction of microbial contamination, disinfestations, sprout inhibition and extension of shelf life of food. However, the commercialization of irradiated food requires the availability of reliable methods to identify irradiated foodstuffs. In this paper, we present results on the application to irradiated chicken of this method, based on the detection, in muscle and skin samples, of the peaks of ions 98 Da and 112 Da, in a ratio approximately 4:1, typical of radiation induced 2-dodecylcyclobutanones (2-DCB). Aim of the work was also to study the time stability of the measured parameters in samples irradiated at 3 and 5 kGy, and to verify the efficacy of the treatment from a microbiological point of view. Our results show that, one month after irradiation at 3 kGy, the method is suitable using the skin but not the muscle, while the measured parameters are detectable in both samples irradiated at 5 kGy. The microbial population was substantially reduced even at 3 kGy.

  13. Gas chromatographic/mass spectrometric and microbiological analyses on irradiated chicken

    Energy Technology Data Exchange (ETDEWEB)

    Parlato, A. [Dipartimento di Ingegneria Nucleare, Universita di Palermo, Viale delle Scienze, Edificio 6, 90100 Palermo (Italy); Calderaro, E. [Dipartimento di Ingegneria Nucleare, Universita di Palermo, Viale delle Scienze, Edificio 6, 90100 Palermo (Italy); Bartolotta, A. [Dipartimento Farmacochimico, Tossicologico e Biologico, Universita di Palermo, via Archirafi 32, 90123 Palermo (Italy)]. E-mail: antonio.bartolotta@unipa.it; D' Oca, M.C. [Dipartimento Farmacochimico, Tossicologico e Biologico, Universita di Palermo, via Archirafi 32, 90123 Palermo (Italy); Giuffrida, S.A. [Dipartimento Farmacochimico, Tossicologico e Biologico, Universita di Palermo, via Archirafi 32, 90123 Palermo (Italy); Brai, M. [Dipartimento di Fisica e Tecnologie Relative, Universita di Palermo, Viale delle Scienze, Edificio 18, 90100 Palermo (Italy); Tranchina, L. [Dipartimento di Fisica e Tecnologie Relative, Universita di Palermo, Viale delle Scienze, Edificio 18, 90100 Palermo (Italy); Agozzino, P. [Dipartimento di Chimica e Tecnologie Farmaceutiche, Universita di Palermo, via Archirafi 32, 90123 Palermo (Italy); Avellone, G. [Dipartimento di Chimica e Tecnologie Farmaceutiche, Universita di Palermo, via Archirafi 32, 90123 Palermo (Italy); Ferrugia, M. [Dipartimento di Chimica e Tecnologie Farmaceutiche, Universita di Palermo, via Archirafi 32, 90123 Palermo (Italy); Di Noto, A.M. [Istituto Zooprofilattico Sperimentale della Sicilia ' A.Mirri' , Palermo (Italy); Caracappa, S. [Istituto Zooprofilattico Sperimentale della Sicilia ' A.Mirri' , Palermo (Italy)

    2007-08-15

    Ionizing radiation is widely used as treatment technique for food preservation. It involves among others reduction of microbial contamination, disinfestations, sprout inhibition and extension of shelf life of food. However, the commercialization of irradiated food requires the availability of reliable methods to identify irradiated foodstuffs. In this paper, we present results on the application to irradiated chicken of this method, based on the detection, in muscle and skin samples, of the peaks of ions 98 Da and 112 Da, in a ratio approximately 4:1, typical of radiation induced 2-dodecylcyclobutanones (2-DCB). Aim of the work was also to study the time stability of the measured parameters in samples irradiated at 3 and 5 kGy, and to verify the efficacy of the treatment from a microbiological point of view. Our results show that, one month after irradiation at 3 kGy, the method is suitable using the skin but not the muscle, while the measured parameters are detectable in both samples irradiated at 5 kGy. The microbial population was substantially reduced even at 3 kGy.

  14. Gas chromatographic/mass spectrometric and microbiological analyses on irradiated chicken

    International Nuclear Information System (INIS)

    Parlato, A.; Calderaro, E.; Bartolotta, A.; D'Oca, M.C.; Giuffrida, S.A.; Brai, M.; Tranchina, L.; Agozzino, P.; Avellone, G.; Ferrugia, M.; Di Noto, A.M.; Caracappa, S.

    2007-01-01

    Ionizing radiation is widely used as treatment technique for food preservation. It involves among others reduction of microbial contamination, disinfestations, sprout inhibition and extension of shelf life of food. However, the commercialization of irradiated food requires the availability of reliable methods to identify irradiated foodstuffs. In this paper, we present results on the application to irradiated chicken of this method, based on the detection, in muscle and skin samples, of the peaks of ions 98 Da and 112 Da, in a ratio approximately 4:1, typical of radiation induced 2-dodecylcyclobutanones (2-DCB). Aim of the work was also to study the time stability of the measured parameters in samples irradiated at 3 and 5 kGy, and to verify the efficacy of the treatment from a microbiological point of view. Our results show that, one month after irradiation at 3 kGy, the method is suitable using the skin but not the muscle, while the measured parameters are detectable in both samples irradiated at 5 kGy. The microbial population was substantially reduced even at 3 kGy

  15. Gas chromatographic/mass spectrometric characterization of dromostanolone metabolites in human urine

    International Nuclear Information System (INIS)

    Kim, Tae Wook; Choi, Man Ho; Jung, Byung Hwa; Chung, Bong Chul

    1998-01-01

    The metabolism of dromostanolone (2α-methyl-5α-androstan-17β-ol-3-one) was studied in three adult volunteers after oral dose of 20 mg. Solvent extracts of urine obtained after enzyme hydrolysis were derivatized with MSTFA/TMCS and MSTFA/TMIS. The structures of intact drug and its metabolites were determined by gas chromatography/mass spectrometry (GC/MS) in electron impact (EI) mode. The major metabolite (2α-methyl-5α-androstan-3α-ol-17-one), its 3β-epimer, parent compound, and several hydroxylated metabolites including intact drug were detected by comparing total ion chromatograms of control urine with that of the administered sample. Two epimers of 2α-methyl-5α-androstan-3, 17β-diol were detected using selected ion monitoring. The maximum excretion of dromostanolone and 2α-methyl-5α-androstan-3α-ol-17-one was reached in 6.2-15 hr. The half-life of intact dromostanolone was 5.3 hr. About 3.0% of the administered amount was found to be excreted within 95 hr as unchanged form

  16. Gas chromatographic-mass spectrometric determination of hydrophilic compounds in environmental water by solid-phase extraction with activated carbon fiber felt.

    Science.gov (United States)

    Kawata, K; Ibaraki, T; Tanabe, A; Yagoh, H; Shinoda, A; Suzuki, H; Yasuhara, A

    2001-03-09

    Simple gas chromatographic-mass spectrometric determination of hydrophilic organic compounds in environmental water was developed. A cartridge containing activated carbon fiber felt was made by way of trial and was evaluated for solid-phase extraction of the compounds in water. The hydrophilic compounds investigated were acrylamide, N,N-dimethylacetamide, N,N-dimethylformamide, 1,4-dioxane, furfural, furfuryl alcohol, N-nitrosodiethylamine and N-nitrosodimethylamine. Overall recoveries were good (80-100%) from groundwater and river water. The relative standard deviations ranged from 4.5 to 16% for the target compounds. The minimum detectable concentrations were 0.02 to 0.03 microg/l. This method was successfully applied to several river water samples.

  17. Validation and implementation of liquid chromatographic-mass spectrometric (LC-MS) methods for the quantification of tenofovir prodrugs.

    Science.gov (United States)

    Hummert, Pamela; Parsons, Teresa L; Ensign, Laura M; Hoang, Thuy; Marzinke, Mark A

    2018-04-15

    The nucleotide reverse transcriptase inhibitor tenofovir (TFV) is widely administered in a disoproxil prodrug form (tenofovir disoproxil fumarate, TDF) for HIV management and prevention. Recently, novel prodrugs tenofovir alafenamide fumarate (TAF) and hexadecyloxypropyl tenofovir (CMX157) have been pursued for HIV treatment while minimizing adverse effects associated with systemic TFV exposure. Dynamic and sensitive bioanalytical tools are required to characterize the pharmacokinetics of these prodrugs in systemic circulation. Two parallel methods have been developed, one to combinatorially quantify TAF and TFV, and a second method for CMX157 quantification, in plasma. K 2 EDTA plasma was spiked with TAF and TFV, or CMX157. Following the addition of isotopically labeled internal standards and sample extraction via solid phase extraction (TAF and TFV) or protein precipitation (CMX157), samples were subjected to liquid chromatographic-tandem mass spectrometric (LC-MS/MS) analysis. For TAF and TFV, separation occurred using a Zorbax Eclipse Plus C18 Narrow Bore RR, 2.1 × 50 mm, 3.5 μm column and analytes were detected on an API5000 mass analyzer; CMX157 was separated using a Kinetex C8, 2.1 × 50 mm, 2.6 μm column and quantified using an API4500 mass spectrometer. Methods were validated according to FDA Bioanalytical Method Validation guidelines. Analytical methods: were optimized for the multiplexed monitoring of TAF and TFV, and CMX157 in plasma. The lower limits of quantification (LLOQs) for TAF, TFV, and CMX157 were 0.03, 1.0, and 0.25 ng/mL, respectively. Calibration curves were generated via weighted linear regression of standards. Intra- and inter-assay precision and accuracy studies demonstrated %CVs ≤ 14.4% and %DEVs ≤ ± 7.95%, respectively. Stability and matrix effects studies were also performed. All results were acceptable and in accordance with the recommended guidelines for bioanalytical methods. Assays were also

  18. A gas/liquid chromatographic-mass spectrometric method for the rapid screening of 250 pesticides in aqueous matrices

    Energy Technology Data Exchange (ETDEWEB)

    Chandramouli, B.; Harvan, D.; Brittain, S.; Hass, R. [Eno River Labs, LLC. Durham, NC (United States)

    2004-09-15

    Pesticide residues in food present a potentially serious and significant cause for concern. Many pesticides have been associated with significant health effects to the nervous and endocrine systems and some have been deemed carcinogenic. There are many well-established techniques for pesticide analysis. However, commercial pesticide methods have traditionally only been available for specific pesticide families, such as chlorinated pesticides or herbicides, and at detection limits ranging from 0.05 ppb to 1 ppm in aqueous matrices. Techniques that can quickly screen for the presence/absence of pesticide residues in food matrices are critical in ensuring the safety of food and water. This paper outlines a combined Gas Chromatographic-High Resolution Mass Spectrometric (GC-HRMS) and Liquid Chromatographic Tandem Mass Spectrometric (LC-MS/MS) screening assay for 250 pesticides that was developed for use in water, and soda samples at screening levels ranging from 0.1-5 ppb. The pesticides selected have been identified by the European Union as being of concern and the target of possible legislation. The list encompasses a variety of pesticide classes and compound groupings.

  19. Gas chromatographic-mass spectrometric analysis of di(2-ethylhexyl) phthalate and its metabolites in hepatic microsomal incubations

    Energy Technology Data Exchange (ETDEWEB)

    Pietrogrande, M.C.; Rossi, D.; Paganetto, G

    2003-03-17

    A method is reported for the determination of di(2-ethylhexyl) phthalate (DEHP) and its metabolites in in vitro metabolism studies. Gas chromatography-mass spectrometry (GC-MS) analysis allows separation of 18 by-products of DEHP metabolism. On the basis of retention time and specific mass spectra m/z values, three classes of compounds can be identified: (i) alcohols as hydrolysis product; (ii) acids produced by alcohol oxidation; (iii) compounds retaining phthalic moiety. The chromatogram can also be acquired in SIM mode at m/z 149 resulting in 13 well-separated chromatographic peaks: from retention time and mass spectra it can be inferred that the main peaks correspond to mono(2-ethylhexyl) phthalate (MEHP) and ({omega}-1)-hydroxyl-MEHP. The kinetics of DEHP metabolism was studied using an S9 Aroclor-induced liver fraction as in vitro model and following incubation assay after 20, 40, 60 and 90 min. The composition of incubation mixtures can be quantitatively evaluated from selected ion monitoring chromatograms at m/z 149: the by-product concentration increases during the incubation time, as a consequence of DEHP degradation. During the incubation test a significant conversion of DEHP into MEHP is observed: a conversion yield of 10, 13, 16 and 20% of the original DEHP is obtained after 20, 40, 60 and 90 min, respectively. The metabolic conversion of DEHP to MEHP explains the endocrine-disrupting activity of the original DEHP; moreover, it has been demonstrated that MEHP and its ({omega}-1)-oxidation metabolite induce peroxisome proliferation. This result strengthens the suggestion that the study of DEHP metabolic pathway is fundamental to better understanding its toxicological behavior.

  20. Gas chromatographic/mass spectrometric determination of aniline in foods oils associated with the Spanish toxic oil syndrome

    International Nuclear Information System (INIS)

    Hill, R.H. Jr.; Todd, G.D.; Kilbourne, E.M.; Cline, R.E.; McCraw, J.; Orti, D.L.; Bailey, S.L.; Needham, L.L.

    1987-01-01

    In 1981, a new disease, known today as the toxic oil syndrome (TOS), descended upon the people of Spin. A strong association between TOS and contaminated food oil was established early. Subsequent investigations implicated food oils containing rapeseed oil denatured with aniline. However, little aniline was found in the oils; some other etiologic agent in the oil had apparently produced the illness. Many researchers have investigated these oils, but the specific etiologic agent has not been identified. Significant progress in this research has been hampered by the difficulty in identifying the specific oil samples that produced illness in specific TOS cases. In 1984, the Spanish Government invited the Centers for Disease Control (CDC) to participate in its research efforts to study the TOS problem. One of the authors was detailed to Spain to assist in the study of the illness. Part of their work in this area has been an attempt in their laboratories to classify a group of blind-coded case and control oils according to selected chemical measurements. They report here a newly developed method for determining aniline in these oils and the results of these analyses

  1. [Chromatographic mass spectrometric determination of low-molecular-weight aromatic compounds of microbial origin in the serum from patients with sepsis].

    Science.gov (United States)

    Beloborodova, N V; Arkhipova, A S; Beloborodov, D M; Boĭko, N B; Mel'ko, A I; Olenin, A Iu

    2006-02-01

    The investigation quantitatively determined the content of low-molecular-weight aromatic compounds of microbial origin in the sera of 34 individuals by chromatographic mass spectrometry. An "Agilent Technogies 6890N" gas chromatograph with a 5973 mass selective detector was applied; chromatographic separation of components was effected on an Hp-5MS quartz capillary column. Aromatic small molecules originating from microbes (SMOM) were determined in the sera of 7 patients with sepsis. The diagnosis of sepsis was documented by the presence of the systemic inflammation syndrome and by that of bacteriemia and/or artificial ventilation-associated pneumonia along with the level of procalcitonin of higher than 10 ng/ml. The levels of aromatic SMOM were compared in 10 healthy donors, 8 preoperative cardiosurgical patients, and 9 patients with different abnormalities without sepsis treated in an intensive care unit (ICU). Serum phenylacetic and 3-phenylpropionic acids were found to be prevalent in the healthy donors and postoperative cardiosurgical patients. In ICU patients with different complications without sepsis, more than half the compounds under study were undetectable, the others were found in very low concentrations, which may be accounted for by antibiotic therapy. At the same time, almost the whole spectrum of the test compounds (other than 3-phenylpropionic acid) with the highest concentrations of 3-phenyllactic, p-hydroxyphenylacetic, 3-(p-hydroxyphenyl)lactic and 2-hydroxybutanic acids, was detectable in septic patients receiving a more intensive therapy. The differences were statistically significant (by the Mann-Whitney U-test; p < 0.05). By taking into account the potentially high biological activity of the test compounds, studies are to be continued in this area.

  2. Development and validation of a highly sensitive gas chromatographic-mass spectrometric screening method for the simultaneous determination of nanogram levels of fentanyl, sufentanil and alfentanil in air and surface contamination wipes.

    Science.gov (United States)

    Van Nimmen, Nadine F J; Veulemans, Hendrik A F

    2004-05-07

    A highly sensitive gas chromatographic-mass spectrometric (GC-MS) analytical method for the determination of the opioid narcotics fentanyl, alfentanil, and sufentanil in industrial hygiene personal air samples and surface contamination wipes was developed and comprehensively validated. Sample preparation involved a single step extraction of the samples with methanol, fortified with a fixed amount of the penta-deuterated analogues of the opioid narcotics as internal standard. The GC-MS analytical procedure using selected ion monitoring (SIM) was shown to be highly selective. Linearity was shown for levels of extracted wipe and air samples corresponding to at least 0.1-2 times their surface contamination limit (SCL) and accordingly to 0.1-2 times their time weighted average occupational exposure limit (OEL-TWA) based on a full shift 9601 air sample. Extraction recoveries were determined for spiked air samples and surface wipes and were found to be quantitative for both sampling media in the entire range studied. The air sampling method's limit of detection (LOD) was determined to be 0.4 ng per sample for fentanyl and sufentanil and 1.6 ng per sample for alfentanil, corresponding to less than 1% of their individual OEL for a full shift air sample (9601). The limit of quantification (LOQ) was found to be 1.4, 1.2, and 5.0 ng per filter for fentanyl, sufentanil, and alfentanil, respectively. The wipe sampling method had LODs of 4 ng per wipe for fentanyl and sufentanil and 16 ng per wipe for alfentanil and LOQs of respectively, 14, 12, and 50 ng per wipe. The analytical intra-assay precision of the air sampling and wipe sampling method, defined as the coefficient of variation on the analytical result of six replicate spiked media was below 10 and 5%, respectively, for all opioids at all spike levels. Accuracy expressed as relative error was determined to be below 10%, except for alfentanil at the lowest spike level (-13.1%). The stability of the opioids during simulated

  3. A quantitative structure- property relationship of gas chromatographic/mass spectrometric retention data of 85 volatile organic compounds as air pollutant materials by multivariate methods

    Directory of Open Access Journals (Sweden)

    Sarkhosh Maryam

    2012-05-01

    Full Text Available Abstract A quantitative structure-property relationship (QSPR study is suggested for the prediction of retention times of volatile organic compounds. Various kinds of molecular descriptors were calculated to represent the molecular structure of compounds. Modeling of retention times of these compounds as a function of the theoretically derived descriptors was established by multiple linear regression (MLR and artificial neural network (ANN. The stepwise regression was used for the selection of the variables which gives the best-fitted models. After variable selection ANN, MLR methods were used with leave-one-out cross validation for building the regression models. The prediction results are in very good agreement with the experimental values. MLR as the linear regression method shows good ability in the prediction of the retention times of the prediction set. This provided a new and effective method for predicting the chromatography retention index for the volatile organic compounds.

  4. Ionic liquid-based single-drop microextraction/gas chromatographic/mass spectrometric determination of benzene, toluene, ethylbenzene and xylene isomers in waters.

    Science.gov (United States)

    Aguilera-Herrador, Eva; Lucena, Rafael; Cárdenas, Soledad; Valcárcel, Miguel

    2008-08-01

    The direct coupling between ionic liquid-based single-drop microextraction and gas chromatography/mass spectrometry is proposed for the rapid and simple determination of benzene, toluene, ethylbenzene and xylenes isomers (BTEX) in water samples. The extraction procedure exploits not only the high affinity of the selected ionic liquid (1-methyl-3-octyl-imidazolium hexaflourophosphate) to these aromatic compounds but also its special properties like viscosity, low vapour pressure and immiscibility with water. All the variables involved in the extraction process have been studied in depth. The developed method allows the determination of these single-ring compounds in water under the reference concentration level fixed by the international legislation. In this case, limits of detection were in the range 20 ng L(-1) (obtained for benzene) and 91 ng L(-1) (for o-xylene). The repeatability of the proposed method, expressed as RSD (n=5), varied between 3.0% (o-xylene) and 5.2% (toluene).

  5. Gas chromatographic-mass spectrometric investigation of n-alkanes and carboxylic acids in bottom sediments of the northern Caspian Sea

    Science.gov (United States)

    Kenzhegaliev, Akimgali; Zhumagaliev, Sagat; Kenzhegalieva, Dina; Orazbayev, Batyr

    2018-03-01

    Prior to the start of experimental oil production in the Kashagan field (northern part of the Caspian Sea), n-alkanes and carboxylic acids contained in samples obtained from bottom sediments in the area of artificial island "D" were investigated by gas chromatography-mass spectrometry. Concentrations of 10 n-alkanes (composed of C10-C13, C15-C20) and 11 carboxylic acids (composed of C6-C12, C14-C16) were identified and measured. Concentrations of individual alkanes and carboxylic acids in bottom sediments of the various samples varied between 0.001 ÷ 0.88 μg/g and 0.001 ÷ 1.94 μg/g, respectively. Mass spectra, in particular the M+ molecular ion peak and the most intense peaks of fragment ions, are given. The present study illustrates the stability of molecular ions to electronic ionisation and the main fragment ions to the total ion current and shows that the initial fragmentation of alkanes implies radical cleavage of C2H5 rather than CH3. All aliphatic monocarboxylic acids studied were characterised by McLafferty rearrangement leading to the formation of F4 cation-radical with m/z 60 and F3 cation-radical with m/z 88 in the case of ethylhexanoic acid. The formation of oxonium ions presents another important aspect of acid fragmentation. Using mass numbers of oxonium ions and rearrangement ions allows determination of the substitution character in α- and β- C atoms. The essence of our approach is to estimate the infiltration of hydrocarbon fluids from the enclosing formation into sea water, comprising an analysis of derivatives of organic compounds in bottom sediments. Thus, concentrations of derived organic molecules can serve as a basis for estimates of the depth at which hydrocarbon fluids leak, i.e., to serve as an auxiliary technique in the search for hydrocarbon deposits and to repair well leaks.

  6. Liquid chromatographic-mass spectrometric method for ...

    African Journals Online (AJOL)

    Pharmacotherapy Group, Faculty of Pharmacy, University of Benin, Benin City, 300001 Nigeria. All rights reserved. ... Additionally, tablet splitting can minimize treatment costs for patients. [6]. ..... using the design space approach. Talanta. 2013 ...

  7. Liquid chromatographic-mass spectrometric method for ...

    African Journals Online (AJOL)

    and weighed with the analytical balance. .... was analyzed occasionally to ensure the .... Retention time .... The authors declare that this work was done by .... Life Sci. 2002; 767: 341–351. 31. US Pharmacopeial Convention. United States.

  8. Gas Chromatographic-Mass Spectrometric Analysis of Essential Oil ...

    African Journals Online (AJOL)

    hepatitis, dysmenorrhea, stomatitis, duodenitis and depression in south China [1]. There are few reports about its chemical constituents and pharmacological properties, such as the hydroalcoholic extract from the buds of. Jasminum grandiflorum showing preferable antiviral efficacy against HBV replication in. HepG2 2.2.15 ...

  9. Gas Chromatographic-Mass Spectrometric Analysis of Essential Oil ...

    African Journals Online (AJOL)

    Purpose: To analyze the essential oil composition of the flower of Jasminum officinale L. var. grandifloroum L. (Jasminum grandiflorum) by gas chromatography-mass spectrometry (GC-MS). Methods: The optimum GC-MS conditions used for the analysis were 250 oC inlet temperature, 150 oC MSD detector temperature, ...

  10. Chromatographic-mass spectrometric analysis of ethanol extract of ...

    African Journals Online (AJOL)

    Methods: The dried root of Maesa perlaria var. formosana was extracted with 95 % ethanol for composition analysis under the following optimum GC-MS conditions: 250 °C inlet temperature, 250 °C MSD detector temperature, and GC oven temperature programmed as follows: initial temperature held at 70 °C for 15 min, ...

  11. An aircraft gas chromatograph-mass spectrometer System for Organic Fast Identification Analysis (SOFIA): design, performance and a case study of Asian monsoon pollution outflow

    Science.gov (United States)

    Bourtsoukidis, Efstratios; Helleis, Frank; Tomsche, Laura; Fischer, Horst; Hofmann, Rolf; Lelieveld, Jos; Williams, Jonathan

    2017-12-01

    Volatile organic compounds (VOCs) are important for global air quality and oxidation processes in the troposphere. In addition to ground-based measurements, the chemical evolution of such species during transport can be studied by performing in situ airborne measurements. Generally, aircraft instrumentation needs to be sensitive, robust and sample at higher frequency than ground-based systems while their construction must comply with rigorous mechanical and electrical safety standards. Here, we present a new System for Organic Fast Identification Analysis (SOFIA), which is a custom-built fast gas chromatography-mass spectrometry (GC-MS) system with a time resolution of 2-3 min and the ability to quantify atmospheric mixing ratios of halocarbons (e.g. chloromethanes), hydrocarbons (e.g isoprene), oxygenated VOCs (acetone, propanal, butanone) and aromatics (e.g. benzene, toluene) from sub-ppt to ppb levels. The relatively high time resolution is the result of a novel cryogenic pre-concentration unit which rapidly cools (˜ 6 °C s-1) the sample enrichment traps to -140 °C, and a new chromatographic oven designed for rapid cooling rates (˜ 30 °C s-1) and subsequent thermal stabilization. SOFIA was installed in the High Altitude and Long Range Research Aircraft (HALO) for the Oxidation Mechanism Observations (OMO) campaign in August 2015, aimed at investigating the Asian monsoon pollution outflow in the tropical upper troposphere. In addition to a comprehensive instrument characterization we present an example monsoon plume crossing flight as a case study to demonstrate the instrument capability. Hydrocarbon, halocarbon and oxygenated VOC data from SOFIA are compared with mixing ratios of carbon monoxide (CO) and methane (CH4), used to define the pollution plume. By using excess (ExMR) and normalized excess mixing ratios (NEMRs) the pollution could be attributed to two air masses of distinctly different origin, identified by back-trajectory analysis. This work

  12. Energy dispersive X-Ray fluorescence spectrometric study of ...

    African Journals Online (AJOL)

    Energy dispersive X-Ray fluorescence spectrometric study of compositional differences in trace elements in dried Moringa oleifera leaves grown in two different agro-ecological locations in Ebonyi State, Nigeria.

  13. Mars Solar Balloon Landed Gas Chromatograph Mass Spectrometer

    Science.gov (United States)

    Mahaffy, P.; Harpold, D.; Niemann, H.; Atreya, S.; Gorevan, S.; Israel, G.; Bertaux, J. L.; Jones, J.; Owen, T.; Raulin, F.

    1999-01-01

    A Mars surface lander Gas Chromatograph Mass Spectrometer (GCMS) is described to measure the chemical composition of abundant and trace volatile species and isotope ratios for noble gases and other elements. These measurements are relevant to the study of atmospheric evolution and past climatic conditions. A Micromission plan is under study where a surface package including a miniaturized GCMS would be delivered to the surface by a solar heated hot air balloon based system. The balloon system would be deployed about 8 km above the surface of Mars, wherein it would rapidly fill with Martian atmosphere and be heated quickly by the sun. The combined buoyancy and parachuting effects of the solar balloon result in a surface package impact of about 5 m/sec. After delivery of the package to the surface, the balloon would ascend to about 4 km altitude, with imaging and magnetometry data being taken for the remainder of the daylight hours as the balloon is blown with the Martian winds. Total atmospheric entry mass of this mission is estimated to be approximately 50 kg, and it can fit as an Ariane 5 piggyback payload. The GCMS would obtain samples directly from the atmosphere at the surface and also from gases evolved from solid phase material collected from well below the surface with a Sample Acquisition and Transport Mechanism (SATM). The experiment envisioned in the Mars Micromission described would obtain samples from a much greater depth of up to one meter below the surface, and would search for organic molecules trapped in ancient stratified layers well below the oxidized surface. Insitu instruments on upcoming NASA missions working in concert with remote sensing measurement techniques have the potential to provide a more detailed investigation of mineralogy and the extent of simple volatiles such as CO2 and H2O in surface and subsurface solid phase materials. Within the context of subsequent mission opportunities such as those provided by the Ariane 5 piggyback

  14. Recent Advances in Water Analysis with Gas Chromatograph Mass Spectrometers

    Science.gov (United States)

    MacAskill, John A.; Tsikata, Edem

    2014-01-01

    We report on progress made in developing a water sampling system for detection and analysis of volatile organic compounds in water with a gas chromatograph mass spectrometer (GCMS). Two approaches are described herein. The first approach uses a custom water pre-concentrator for performing trap and purge of VOCs from water. The second approach uses a custom micro-volume, split-splitless injector that is compatible with air and water. These water sampling systems will enable a single GC-based instrument to analyze air and water samples for VOC content. As reduced mass, volume, and power is crucial for long-duration, manned space-exploration, these water sampling systems will demonstrate the ability of a GCMS to monitor both air and water quality of the astronaut environment, thereby reducing the amount of required instrumentation for long duration habitation. Laboratory prototypes of these water sampling systems have been constructed and tested with a quadrupole ion trap mass spectrometer as well as a thermal conductivity detector. Presented herein are details of these water sampling system with preliminary test results.

  15. Automated solid-phase extraction of herbicides from water for gas chromatographic-mass spectrometric analysis

    Science.gov (United States)

    Meyer, M.T.; Mills, M.S.; Thurman, E.M.

    1993-01-01

    An automated solid-phase extraction (SPE) method was developed for the pre-concentration of chloroacetanilide and triazine herbicides, and two triazine metabolites from 100-ml water samples. Breakthrough experiments for the C18 SPE cartridge show that the two triazine metabolites are not fully retained and that increasing flow-rate decreases their retention. Standard curve r2 values of 0.998-1.000 for each compound were consistently obtained and a quantitation level of 0.05 ??g/l was achieved for each compound tested. More than 10,000 surface and ground water samples have been analyzed by this method.

  16. Mass spectrometric study of Nd2S3 vaporization

    International Nuclear Information System (INIS)

    Fenochka, B.V.

    1987-01-01

    The authors conduct a mass-spectrometric study of neodymium(III) sulfide vaporization. The chemical composition of the samples was stoichiometric and the samples were vaporized from tantalum effusion cells. When the vapor over Nd 2 S 3 is ionized by electrons the mass spectra shows monovalent cations of Nd, S, NdS, and NdO. The enthalpy of vaporization if Nd atoms from Nd 2 S 3 at average experimental temperatures and the standard enthalpy of reaction is shown. Also presented is the enthalpy of vaporization of NdS molecules from Nd 2 S 3 at average experimental temperatures and the standard enthalpy of reaction

  17. Mass spectrometric study of vaporization of cesium tellurate and tellurite

    International Nuclear Information System (INIS)

    Semenov, G.A.; Fokina, L.A.; Mouldagalieva, R.A.

    1994-01-01

    The process of vaporization of cesium tellurate and tellurite was studied by the Knudsen effusion method with a mass spectrometric analysis of the vapor composition. The thermal dissociation of Cs 2 TeO 4 to Cs 2 TeO 3 and the congruent vaporization of Cs 2 TeO 3 were established. Thermodynamic functions for gaseous Cs 2 TeO 3 have been calculated. The standard enthalpy of sublimation Δ s H (298.15)=268.1±13.0 kJ mol -1 was determined by the 2nd and 3rd laws of thermodynamics. The enthalpy of formation Δ f H (298.15)=-725.1±13.0 kJ mol -1 for gaseous Cs 2 TeO 3 and the enthalpy of atomization Δ at H (298.15)=1841.3±15.0 kJ mol -1 have been computed. ((orig.))

  18. The theoretical study of full spectrum analysis method for airborne gamma-ray spectrometric data

    International Nuclear Information System (INIS)

    Ni Weichong

    2011-01-01

    Spectra of airborne gamma-ray spectrometry was found to be the synthesis of spectral components of radioelement sources by analyzing the constitution of radioactive sources for airborne gamma-ray spectrometric survey and establishing the models of gamma-ray measurement. The mathematical equation for analysising airborne gamma-ray full spectrometric data can be expressed into matrix and related expansions were developed for the mineral resources exploration, environmental radiation measurement, nuclear emergency monitoring, and so on. Theoretical study showed that the atmospheric radon could be directly computed by airborne gamma-ray spectrometric data with full spectrum analysis without the use of the accessional upward-looking detectors. (authors)

  19. Study of natural diamond detector spectrometric properties under neutron irradiation

    CERN Document Server

    Alekseyev, A B; Kaschuck, Y; Krasilnikov, A; Portnov, D; Tugarinov, S

    2002-01-01

    Natural diamond detector (NDD) performance was studied up to a neutron fluence of 10 sup 1 sup 5 neutron/cm sup 2. The variations of the NDD spectrometric response to incident alpha-particles from sup 2 sup 4 sup 1 Am source after exposure to fast neutron fluences up to 3x10 sup 1 sup 6 n/cm sup 2 were examined. No significant variations up to the level of 10 sup 1 sup 4 n/cm sup 2 were observed. Degradation of charge collection efficiency at higher fluences is reported. No remarkable increase of the NDD leakage current and count rate change had been observed up to a neutron fluence of 3x10 sup 1 sup 6 n/cm sup 2. The charge collection efficiency variations of neutron irradiated diamond spectrometer were studied ex situ under gamma-rays, beta-radiation and visible light excitation. Charge collection efficiency restoration up to 75% level and the NDD performance stabilization by extrinsic low-intensity visible light (550 nm

  20. On the Origin of Microheterogeneity : A Mass Spectrometric Study of Dimethyl Sulfoxide-Water Binary Mixture

    NARCIS (Netherlands)

    Shin, Dong Nam; Wijnen, Jan W.; Engberts, Jan B.F.N.; Wakisaka, Akihiro

    2001-01-01

    We have studied the microscopic solvent structure of dimethyl sulfoxide-water mixtures and its influence on the solvation structure of solute from a clustering point of View, by means of a specially designed mass spectrometric system. It was observed that the propensity to the cluster formation is

  1. Extraction estimation and gas chromatographic mass spectrometric analysis of the non polar fraction of the pistia stratiotes

    International Nuclear Information System (INIS)

    Hussain, Z.

    2013-01-01

    The non-polar compounds of the Pistia stratiotes were extracted using n-hexane as solvent. The extraction yields were determined both for the cold and hot extraction procedure as 8.50 +- 0.05% and 12.00 +- 0.05%, respectively. The extract was analyzed and separated into its components using GC equipped with FID and GC mass in separate experiments. The most important compounds identified in n-hexane extract of leaves of P. stratiotes are long chain compound of the nitrogenous nature and oxygenated compounds of mixed functional groups. The antibacterial activity of this fraction was investigated against eight pathogenic bacteria using disc diffusion method. Larger zones of inhibition were observed for Bacillus subtilis, Pseudomonas aeruginosa and Agrobacterium tumefaciens as compared to Klebsiella pneumoniaee and Staphylococcus aureus where the activity was relatively less. No activity was observed against Escherichia coli, Salmonella typhi and Bacillus atrophaeus. (author)

  2. Solid-phase microextraction for gas chromatographic/mass spectrometric analysis of dimethoate in human biological samples.

    Science.gov (United States)

    Gallardo, E; Barroso, M; Margalho, C; Cruz, A; Vieira, D N; López-Rivadulla, M

    2006-01-01

    A new, simple and rapid procedure for the determination of dimethoate in urine and blood samples was developed using direct immersion solid-phase microextraction and gas chromatography/mass spectrometry. This technique required only 0.1 mL of sample, and ethion was used as internal standard. Two types of coated fibre were compared (100 microm polydimethylsiloxane, and 65 microm Carbowax/divinylbenzene). Other parameters, such as extraction temperature, adsorption and desorption time, salt addition, agitation and pH, were optimized to enhance the sensitivity of the method. Limits of detection (LODs) and quantitation (LOQs) were 50 and 100 ng/mL for urine and 200 and 500 ng/mL for blood, respectively. The method was found to be linear between the LOQ and 40 microg/mL for urine, and between the LOQ and 50 microg/mL for blood, with correlation coefficients ranging from 0.9923-0.9996. Precision (intra- and interday) and accuracy were in conformity with the criteria normally accepted in bioanalytical method validation. The mean absolute recoveries of dimethoate were 1.24 and 0.50% for urine and blood, respectively. Because of its simplicity and the fact that small volumes of sample are used, the described method can be successfully used in the diagnosis of poisoning by this pesticide, namely in those situations where the sample volume is limited, as frequently occurs in forensic toxicology. Copyright 2006 John Wiley & Sons, Ltd.

  3. Analysis of Biologic Samples for Morphine and Morphine-Related Compounds by Gas Chromatographic-Mass Spectrometric Methods

    Science.gov (United States)

    1976-04-01

    formation is not necessary if the purpose is to detect diacetylinorphine or methadone but most screening procedures have as their purpose the detection of a...in the following way. Morphine hydrochloride (10.7 mg, 0.1 mM) was dissolved in 600 V1 of dimethylsulfoxide (distilled over calcium hydride). To .i...and the residue was dissolved in ethanol. Normor- phine hydrochloride was precipitated upon addition of n-pentane. Storage of the mixture (freezer

  4. Immunological screening of drugs of abuse and gas chromatographic-mass spectrometric confirmation of opiates and cocaine in hair.

    Science.gov (United States)

    Segura, J; Stramesi, C; Redón, A; Ventura, M; Sanchez, C J; González, G; San, L; Montagna, M

    1999-03-05

    The work presents an analytical strategy to detect drugs of abuse in hair. It involves two sequential steps: a screening by a simple enzyme-linked immunosorbent assay (ELISA) methodology to detect opiates, cocaine and its metabolites, and benzodiacepines, followed by confirmation of opiates and cocaine metabolites in positive samples by gas chromatography coupled to mass spectrometry (GC-MS). In the same GC-MS run other drugs for substitution therapy (e.g. methadone and its main metabolite) can also be detected. After a double washing of hair samples with dichloromethane, hair specimens were cut into small pieces and 10 mg samples were incubated in 2 ml of methanol-trifluoroacetic acid (9:1) mixture, overnight at 37 degrees C. Aliquots of the extract were then evaporated, reconstituted in buffer and analysed according to the ELISA procedure. Confirmation involved solid-phase extraction of another fraction of the extract kept at -20 degrees C, derivatization with heptafluorobutyric anhydride and hexafluoroisopropanol and detection of cocaine, benzoylecgonine, ecgonine methylester, cocaethylene, morphine, codeine, 6-monoacetylmorphine, methadone and 2-ethylidene-1.5-dimethyl-3,3-diphenylpirrolidine (methadone metabolite) by selective ion monitoring after gas chromatographic separation. During the development of the method it was verified that no more than 10% of cocaine, opiates and benzodiacepines were lost when dichloromethane was used to wash real samples. The results also confirmed the increase of extractability power of TFA when it was added to methanol: the recovery for the analytes (cocaine and its metabolites and opiates) added to methanol-TFA alone was of the order of 90% except for benzoylecgonine (75%), and the recovery for the analytes added to methanol-TFA extract of drug-free hair was about 90% for all analytes except for benzoylecgonine and 6-MAM (around 70%). Regarding the stability of labile compounds, only small amounts of ecgonine methylester (2.3%) and morphine (7.2%) were produced, from cocaine and 6-MAM respectively, after the whole extraction procedure and two weeks of storage of methanol-TFA extracts at -20 degrees C. Satisfactory results were obtained when the procedures were applied to the analysis of external proficiency testing hair samples and actual specimens from drug addicts.

  5. Sample enrichment for gas chromatographic mass spectrometric analysis of polynuclear aromatic hydrocarbons in water and in organic mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Bruner, F.; Furlani, G.; Mangani, F.

    1984-10-19

    Among the extraction and preconcentration steps used for polynuclear aromatic hydrocarbons, Soxhlet extraction is largely used for atmospheric dust or other solid material, while liquid-liquid extraction is the method which has been suggested for extraction from water. The use of graphitized carbon black for liquid-solid extraction and preconcentration from water was explored. The properties of different kinds of graphitized carbon black as traps for the extraction and preconcentration of polynuclear aromatic hydrocarbons from water and mineral oil were determined. The best results were obtained with Carbopack F, eluted with toluene at 100 C. Graphitized carbon black is preferred because of its thermal and chemical stability and its high purity, exhibiting no bleeding and possessing high sensitivity. 9 references, 2 figures, 2 tables.

  6. Matrix effect and correction by standard addition in quantitative liquid chromatographic-mass spectrometric analysis of diarrhetic shellfish poisoning toxins.

    Science.gov (United States)

    Ito, Shinya; Tsukada, Katsuo

    2002-01-11

    An evaluation of the feasibility of liquid chromatography-mass spectrometry (LC-MS) with atmospheric pressure ionization was made for quantitation of four diarrhetic shellfish poisoning toxins, okadaic acid, dinophysistoxin-1, pectenotoxin-6 and yessotoxin in scallops. When LC-MS was applied to the analysis of scallop extracts, large signal suppressions were observed due to coeluting substances from the column. To compensate for these matrix signal suppressions, the standard addition method was applied. First, the sample was analyzed and then the sample involving the addition of calibration standards is analyzed. Although this method requires two LC-MS runs per analysis, effective correction of quantitative errors was found.

  7. On the ability of the Viking gas chromatograph-mass spectrometer to detect organic matter.

    Science.gov (United States)

    Biemann, Klaus

    2007-06-19

    A recent paper by Navarro-Gonzalez et al. [Navarro-Gonzalez R, Navarro KF, de la Rosa J, Iniguez E, Molina P, Miranda LD, Morales P, Cienfuegos E, Coll P, Raulin F, et al. (2006) Proc Natl Acad Sci USA 103:16089-16094] claims to show that the Viking GCMS (gas chromatograph-mass spectrometer) experiment, which carried out a search for organic matter at the surface of Mars in 1976, "may have been blind to low levels of organics." To rebut this assertion, the Viking experiment, test data, and results on Mars are reviewed, and the fallacies in the design, execution, and interpretation of the new experiments presented by Navarro-Gonzalez et al. are critically examined.

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

    Science.gov (United States)

    Issa, M M; Nejem, R M; El-Abadla, N S; Al-Kholy, M; Saleh, Akila A

    2008-01-01

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

  9. Mass spectrometric studies of the cluster formation of radon progeny

    International Nuclear Information System (INIS)

    Gong, S.L.

    1993-01-01

    A new experimental system is developed to study the cluster formation of radon progeny with neutral molecules in the environment, which includes a modified mass spectrometer and a surface barrier detector. With the system, the cluster research is carried out at molecular level at which the mass of individual cluster formed is measured. A theory is also proposed to treat the cluster formation as a discrete process based on the ion-dipole and dipole-dipole interactions. Comparison between the theory and experiment is given. (author). 16 refs., 6 figs

  10. Mass spectrometric studies of the cluster formation of radon progeny

    Energy Technology Data Exchange (ETDEWEB)

    Gong, S L [Toronto Univ., ON (Canada). Dept. of Chemical Engineering and Applied Chemistry

    1994-12-31

    A new experimental system is developed to study the cluster formation of radon progeny with neutral molecules in the environment, which includes a modified mass spectrometer and a surface barrier detector. With the system, the cluster research is carried out at molecular level at which the mass of individual cluster formed is measured. A theory is also proposed to treat the cluster formation as a discrete process based on the ion-dipole and dipole-dipole interactions. Comparison between the theory and experiment is given. (author). 16 refs., 6 figs.

  11. Mass spectrometric studies of fast pyrolysis of cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Degenstein, John; Hurt, Matt; Murria, Priya; Easton, McKay; Choudhari, Harshavardhan; Yang, Linan; Riedeman, James; Carlsen, Mark; Nash, John; Agrawal, Rakesh; Delgass, W.; Ribeiro, Fabio; Kenttämaa, Hilkka

    2015-01-01

    A fast pyrolysis probe/linear quadrupole ion trap mass spectrometer combination was used to study the primary fast pyrolysis products (those that first leave the hot pyrolysis surface) of cellulose, cellobiose, cellotriose, cellotetraose, cellopentaose, and cellohexaose, as well as of cellobiosan, cellotriosan, and cellopentosan, at 600°C. Similar products with different branching ratios were found for the oligosaccharides and cellulose, as reported previously. However, identical products (with the exception of two) with similar branching ratios were measured for cellotriosan (and cellopentosan) and cellulose. This result demonstrates that cellotriosan is an excellent small-molecule surrogate for studies of the fast pyrolysis of cellulose and also that most fast pyrolysis products of cellulose do not originate from the reducing end. Based on several observations, the fast pyrolysis of cellulose is suggested to initiate predominantly via two competing processes: the formation of anhydro-oligosaccharides, such as cellobiosan, cellotriosan, and cellopentosan (major route), and the elimination of glycolaldehyde (or isomeric) units from the reducing end of oligosaccharides formed from cellulose during fast pyrolysis.

  12. A vacuum ultraviolet photoionization mass spectrometric study of acetone.

    Science.gov (United States)

    Wei, Lixia; Yang, Bin; Yang, Rui; Huang, Chaoqun; Wang, Jing; Shan, Xiaobin; Sheng, Liusi; Zhang, Yunwu; Qi, Fei; Lam, Chow-Shing; Li, Wai-Kee

    2005-05-19

    The photoionization and dissociative photoionization of acetone have been studied at the photon energy range of 8-20 eV. Photoionization efficiency spectra for ions CH3COCH3+, CH3+, C2H3+, C3H3+, C3H5+, CH(2-)CO+, CH3CO+, C3H4O+, and CH3COCH2+ have been measured. In addition, the energetics of the dissociative photoionization has been examined by ab initio Gaussian-3 (G3) calculations. The computational results are useful in establishing the dissociation channels near the ionization thresholds. With the help of G3 results, the dissociation channels for the formation of the fragment ions CH3CO+, CH2CO+, CH3+, C3H3+, and CH3COCH2+ have been established. The G3 results are in fair to excellent agreement with the experimental data.

  13. Terverticillate Penicillia studied by direct electrospray mass spectrometric profiling of crude extracts: I. Chemosystematics

    DEFF Research Database (Denmark)

    Smedsgaard, Jørn; Frisvad, Jens Christian

    1997-01-01

    ) and Yeast Extract Sucrose agar (YES) directly into the electrospray source of the mass spectrometer. A data matrix was made from each substrate by transferring the complete centroid mass spectrum from 200 to 700 amu as 501 variables to individual columns. No attempt was made to identify ions in the mass......A chemosystematic study of 339 isolates from all known terverticillate Penicillium taxa was performed using electrospray mass spectrometric analysis of extractable metabolites. The mass profiles were made by injecting crude plug extracts made from cultures grown on Czapek Yeast Autolysate agar (CYA...

  14. Vacuum ultraviolet photoionization mass spectrometric study of cyclohexene.

    Science.gov (United States)

    Chen, Jun; Cao, Maoqi; Wei, Bin; Ding, Mengmeng; Shan, Xiaobin; Liu, Fuyi; Sheng, Liusi

    2016-02-01

    In this work, photoionization and dissociation of cyclohexene have been studied by means of coupling a reflectron time-of-flight mass spectrometer with the tunable vacuum ultraviolet (VUV) synchrotron radiation. The adiabatic ionization energy of cyclohexene as well as the appearance energies of its fragment ions C6 H9 (+) , C6 H7 (+) , C5 H7 (+) , C5 H5 (+) , C4 H6 (+) , C4 H5 (+) , C3 H5 (+) and C3 H3 (+) were derived from the onset of the photoionization efficiency (PIE) curves. The optimized structures for the transition states and intermediates on the ground state potential energy surfaces related to photodissociation of cyclohexene were characterized at the ωB97X-D/6-31+g(d,p) level. The coupled cluster method, CCSD(T)/cc-pVTZ, was employed to calculate the corresponding energies with the zero-point energy corrections by the ωB97X-D/6-31+g(d,p) approach. Combining experimental and theoretical results, possible formation pathways of the fragment ions were proposed and discussed in detail. The retro-Cope rearrangement was found to play a crucial role in the formation of C4 H6 (+) , C4 H5 (+) and C3 H5 (+) . Intramolecular hydrogen migrations were observed as dominant processes in most of the fragmentation pathways of cyclohexene. The present research provides a clear picture of the photoionization and dissociation processes of cyclohexene in the 8- to 15.5-eV photon energy region. Copyright © 2016 John Wiley & Sons, Ltd.

  15. How mass spectrometric approaches applied to bacterial identification have revolutionized the study of human gut microbiota.

    Science.gov (United States)

    Grégory, Dubourg; Chaudet, Hervé; Lagier, Jean-Christophe; Raoult, Didier

    2018-03-01

    Describing the human hut gut microbiota is one the most exciting challenges of the 21 st century. Currently, high-throughput sequencing methods are considered as the gold standard for this purpose, however, they suffer from several drawbacks, including their inability to detect minority populations. The advent of mass-spectrometric (MS) approaches to identify cultured bacteria in clinical microbiology enabled the creation of the culturomics approach, which aims to establish a comprehensive repertoire of cultured prokaryotes from human specimens using extensive culture conditions. Areas covered: This review first underlines how mass spectrometric approaches have revolutionized clinical microbiology. It then highlights the contribution of MS-based methods to culturomics studies, paying particular attention to the extension of the human gut microbiota repertoire through the discovery of new bacterial species. Expert commentary: MS-based approaches have enabled cultivation methods to be resuscitated to study the human gut microbiota and thus to fill in the blanks left by high-throughput sequencing methods in terms of culturing minority populations. Continued efforts to recover new taxa using culture methods, combined with their rapid implementation in genomic databases, would allow for an exhaustive analysis of the gut microbiota through the use of a comprehensive approach.

  16. The application study on the prospecting for gold by car-borne gamma-ray spectrometric method in northern Hebei and other areas

    International Nuclear Information System (INIS)

    Ma Zhongxiang; Liu Tengyao; Zhang Peng; Lu Shili; Zhai Yugui; Ma Yanfang

    1995-01-01

    The prospecting method for gold by car-borne gamma-ray spectrometric survey is a new geophysical and geochemical technique in the search for concealed gold deposits which can be used to effectively predict the regional gold metallogenetic potential area. The method of car-borne gamma-ray spectrometric survey was adopted and 63416 data at gamma-ray spectrometric measuring sites from rock masses (or strata) in northern Hebei and other areas (49100 km 2 ) are obtained. On the basis of the size of geological bodies, the sliding filtering technique was applied to process the gamma-ray spectrometric data from regional geological bodies and maps showing the parameter distribution characteristics were plotted (11 sheets). In accordance with the thorough on the distribution characteristics of gamma-ray spectrometric parameters that reflect the regional geological environment of gold metallogenesis, a set of gamma-ray spectrometric combination parameters in correlation with regional gold metallogenesis has been established and the characteristic information of gamma-ray spectrometric parameters has been extracted. Combined with geological information, the gold metallogenetic geological environment in the working area was studied, and two potential areas were predicted. After verification, gold mineralization was encountered in some areas. The study results show that the car-borne gamma-ray spectrometric method used for regional gold prospecting is a rapid, economical and effective one

  17. A review on the mass spectrometric studies of americium: Present status and future perspective.

    Science.gov (United States)

    Aggarwal, Suresh Kumar

    2018-01-01

    The manuscript reviews the various mass spectrometric techniques for analysis and chemical studies of Americium. These methods include thermal ionization mass spectrometry (TIMS), and inductively coupled plasma source mass spectrometry (ICPMS) for the determination of Am isotope ratios and concentration in nuclear fuel samples of interest in nuclear technology, and in complex biological and environmental samples. Ultra-sensitive mass spectrometric techniques of resonance-ionization mass spectrometry (RIMS), and accelerator-based mass spectrometry (AMS) are also discussed. The novel applications of electrospray ionization mass spectrometry (ESIMS) to understand the solution chemistry of Am and other actinides are presented. These studies are important in view of the world-wide efforts to develop novel complexing agents to separate lanthanides and minor actinides (Am, Np, and Cm) for partitioning and transmutation of minor actinides from the point of view of nuclear waste management. These mass spectrometry experiments are also of great interest to examine the covalent character of actinides with increasing atomic number. Studies on gas-phase chemistry of Am and its oxides with Knudsen effusion mass spectrometry (KEMS), Fourier-transform ion cyclotron resonance mass spectrometry (FTICR-MS), and laser-based experiments with reflectron time-of-flight mass spectrometer (R-ToF) are highlighted. These studies are important to understand the fundamental chemistry of 5f electrons in actinides. Requirement of certified isotopic reference materials of Am to improve the accuracy of experimental nuclear data (e.g., the half-life of 243 Am) is emphasized. © 2016 Wiley Periodicals, Inc. Mass Spec Rev. © 2016 Wiley Periodicals, Inc.

  18. Spectrometric techniques 3

    CERN Document Server

    Vanasse, George A

    2013-01-01

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

  19. Mass-Spectrometric Studies of Catalytic Chemical Vapor Deposition Processes of Organic Silicon Compounds Containing Nitrogen

    Science.gov (United States)

    Morimoto, Takashi; Ansari, S. G.; Yoneyama, Koji; Nakajima, Teppei; Masuda, Atsushi; Matsumura, Hideki; Nakamura, Megumi; Umemoto, Hironobu

    2006-02-01

    The mechanism of catalytic chemical vapor deposition (Cat-CVD) processes for hexamethyldisilazane (HMDS) and trisdimethylaminosilane (TDMAS), which are used as source gases to prepare SiNx or SiCxNy films, was studied using three different mass spectrometric techniques: ionization by Li+ ion attachment, vacuum-ultraviolet radiation and electron impact. The results for HMDS show that Si-N bonds dissociate selectively, although Si-C bonds are weaker, and (CH3)3SiNH should be one of the main precursors of deposited films. This decomposition mechanism did not change when NH3 was introduced, but the decomposition efficiency was slightly increased. Similar results were obtained for TDMAS.

  20. Knudsen cell mass spectrometric study of the Cs2IOH(g) molecule thermodynamics

    International Nuclear Information System (INIS)

    Roki, F-Z.; Ohnet, M-N.; Fillet, S.; Chatillon, C.; Nuta, I.

    2013-01-01

    Highlights: • The pronounced ionic character leads to only dissociative ionization processes. • Ions formed are same as those coming from pure dimmers. • De-convolution of the ions origin needs accurate thermodynamic values for the pure gas phase. • Mass spectrometric interpretation has to be performed gradually and as a function of suitable condensed compositions. • Thermal functions have to be fully estimated. -- Abstract: The gas phase of the CsI + CsOH system is analyzed by high temperature Knudsen cell mass spectrometry in order to confirm the existence of the Cs 2 IOH(g) complex molecule. The mass spectrometric analysis is quite complex since such molecules undergo dissociative ionization into fragment ions that mix with the same ions from dimers of the pure compounds in the same vapor phase. Varying the chemical conditions for vaporization by using different CsI + CsOH mixture contents showed that the ionization of the Cs 2 IOH(g) molecule led to five different fragment ions, Cs 2 OH + , Cs 2 I + , Cs + , CsOH + and CsI + . This complex ionization pattern was studied in relation with previous assessed values for the vaporization of CsOH and CsI pure compounds in which monomer and dimer molecules are predominant. The equilibrium constant for the reaction CsI(g) + CsOH(g) = Cs 2 IOH(g) was determined and, after modeling the structure of the Cs 2 IOH molecule, the enthalpy of formation was determined using the third law of thermodynamics, as follows: Δ f H°(Cs 2 IOH, g, 298.15 K) = −578 ± 14.7 kJ · mole −1

  1. Marine gamma spectrometric survey

    International Nuclear Information System (INIS)

    Kostoglodov, V.V.

    1979-01-01

    Presented are theoretical problems physical and geochemical prerequisites and possibilities of practical application of the method of continuous submarine gamma-spectrometric survey and radiometric survey destined for rapid study of the surface layer of marine sediments. Shown is high efficiency and advantages of this method in comparison with traditional and widely spread in marine geology methods of bottom sediments investigation

  2. Topic model-based mass spectrometric data analysis in cancer biomarker discovery studies.

    Science.gov (United States)

    Wang, Minkun; Tsai, Tsung-Heng; Di Poto, Cristina; Ferrarini, Alessia; Yu, Guoqiang; Ressom, Habtom W

    2016-08-18

    A fundamental challenge in quantitation of biomolecules for cancer biomarker discovery is owing to the heterogeneous nature of human biospecimens. Although this issue has been a subject of discussion in cancer genomic studies, it has not yet been rigorously investigated in mass spectrometry based proteomic and metabolomic studies. Purification of mass spectometric data is highly desired prior to subsequent analysis, e.g., quantitative comparison of the abundance of biomolecules in biological samples. We investigated topic models to computationally analyze mass spectrometric data considering both integrated peak intensities and scan-level features, i.e., extracted ion chromatograms (EICs). Probabilistic generative models enable flexible representation in data structure and infer sample-specific pure resources. Scan-level modeling helps alleviate information loss during data preprocessing. We evaluated the capability of the proposed models in capturing mixture proportions of contaminants and cancer profiles on LC-MS based serum proteomic and GC-MS based tissue metabolomic datasets acquired from patients with hepatocellular carcinoma (HCC) and liver cirrhosis as well as synthetic data we generated based on the serum proteomic data. The results we obtained by analysis of the synthetic data demonstrated that both intensity-level and scan-level purification models can accurately infer the mixture proportions and the underlying true cancerous sources with small average error ratios (data, we found more proteins and metabolites with significant changes between HCC cases and cirrhotic controls. Candidate biomarkers selected after purification yielded biologically meaningful pathway analysis results and improved disease discrimination power in terms of the area under ROC curve compared to the results found prior to purification. We investigated topic model-based inference methods to computationally address the heterogeneity issue in samples analyzed by LC/GC-MS. We observed

  3. Reply to "On Vaporization of liquid Pb-Li eutectic alloy from 1000 K to 1200 K- A high temperature mass spectrometric study"

    Science.gov (United States)

    Jain, Uttam; Mukherjee, Abhishek

    2018-03-01

    This communication is in response to a letter to editor commenting on the authors' earlier paper "Vaporization of liquid Pb-Li eutectic alloy from 1000 K to 1200 K - A high temperature mass spectrometric study".

  4. Mass spectrometric study of rhamnolipid biosurfactants and their interactions with cell membrane phospholipids

    Directory of Open Access Journals (Sweden)

    Pashynska V. A.

    2009-12-01

    Full Text Available Aim. To examine the formation of supramolecular complexes of biogenous rhamnolipids with membrane phospholipids that is considered as a molecular mechanism of the biosurfactants antimicrobial action. Method. In the present work rhamnolipid biosurfactant samples produced by Pseudomonas sp. PS-17 strain have been investigated by electrospray ionization mass spectrometry for the first time. Results. As a result of the study, characteristic mass spectra of the rhamnolipid samples were obtained, that can be used as reference spectra for mass spectrometric identification of the compounds in any biological or industrial samples. At the next stage of the experiments the pair systems, containing the biosurfactants and a membrane phospholipid dipalmitoylphosphatidylcholine, have been tested. The cationized noncovalent complexes of the rhamnolipids with the phospholipid were observed in the spectra. Conclusions. The results obtained testify to the consideration that rhamnolipids (similar to other membranotropic agents can form stable supramolecular complexes with membrane phospholipids that are able to evoke the biosurfactants antimicrobial action. A great potential of electrospray ionization mass spectrometry for the biosurfactants identification and study has been demonstrated in the work.

  5. Advanced hyphenated chromatographic-mass spectrometry in mycotoxin determination: current status and prospects.

    Science.gov (United States)

    Li, Peiwu; Zhang, Zhaowei; Hu, Xiaofeng; Zhang, Qi

    2013-01-01

    Mass spectrometric techniques are essential for advanced research in food safety and environmental monitoring. These fields are important for securing the health of humans and animals, and for ensuring environmental security. Mycotoxins, toxic secondary metabolites of filamentous fungi, are major contaminants of agricultural products, food and feed, biological samples, and the environment as a whole. Mycotoxins can cause cancers, nephritic and hepatic diseases, various hemorrhagic syndromes, and immune and neurological disorders. Mycotoxin-contaminated food and feed can provoke trade conflicts, resulting in massive economic losses. Risk assessment of mycotoxin contamination for humans and animals generally depends on clear identification and reliable quantitation in diversified matrices. Pioneering work on mycotoxin quantitation using mass spectrometry (MS) was performed in the early 1970s. Now, unambiguous confirmation and quantitation of mycotoxins can be readily achieved with a variety hyphenated techniques that combine chromatographic separation with MS, including liquid chromatography (LC) or gas chromatography (GC). With the advent of atmospheric pressure ionization, LC-MS has become a routine technique. Recently, the co-occurrence of multiple mycotoxins in the same sample has drawn an increasing amount of attention. Thus, modern analyses must be able to detect and quantitate multiple mycotoxins in a single run. Improvements in tandem MS techniques have been made to achieve this purpose. This review describes the advanced research that has been done regarding mycotoxin determination using hyphenated chromatographic-MS techniques, but is not a full-circle survey of all the literature published on this topic. The present work provides an overview of the various hyphenated chromatographic-MS-based strategies that have been applied to mycotoxin analysis, with a focus on recent developments. The use of chromatographic-MS to measure levels of mycotoxins, including

  6. A comparative study of carbocyanine dyes measured with TOF-SIMS and other mass spectrometric techniques

    International Nuclear Information System (INIS)

    Adriaensen, L.; Vangaever, F.; Gijbels, R.

    2004-01-01

    A series of cationic, zwitterionic and anionic carbocyanine dyes have been measured with TOF-SIMS under Ga + bombardment. In contrast to the cationic dyes, which give very intense molecular ion and characteristic fragment signals in the positive mode, the anionic dyes produce only a few fragment signals of low intensity. Even in the negative mode no molecular ions of the anionic dyes are seen in the recorded spectra. Actually, none of the studied molecules produces negative SIMS spectra containing molecular information. A comparative study was made between TOF-SIMS and other mass spectrometric techniques, namely, fast atom bombardment (FAB), electro spray ionization (ESI) and matrix assisted laser desorption ionization (MALDI). The measurements show that MALDI, ESI as well as FAB all give rise to spectra containing molecular ion signals, either in the positive, in the negative or in both modes. Unlike with TOF-SIMS, this observation also applies to the anionic dyes. Characteristic fragments of the dyes are present in all the recorded spectra. However, TOF-SIMS appears to induce more fragment ions in comparison with the other techniques. ESI, for instance, produces hardly any molecular fragments. Finally, the kind of fragment ions recorded depends upon the technique used, though some signals are produced by various techniques. For these carbocyanine dyes there is no clear correlation between the mass spectra obtained with TOF-SIMS and spectra obtained with the other techniques. This points to different desorption/ionization mechanisms, and makes it difficult, in practice, to make predictions on the feasibility of TOF-SIMS, starting from results of the other MS techniques

  7. Gas chromatographic-mass spectrometric analysis of biomarkers related to folate and cobalamin status in human serum after dimercaptopropanesulfonate reduction and heptafluorobutyl chloroformate derivatization

    Czech Academy of Sciences Publication Activity Database

    Šimek, Petr; Hušek, Petr; Zahradníčková, Helena

    2008-01-01

    Roč. 80, č. 15 (2008), s. 5776-5782 ISSN 0003-2700 R&D Projects: GA ČR GA303/06/1674 Institutional research plan: CEZ:AV0Z50070508 Keywords : biomarkers * gas chromatographic * chloroformate derivatization Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 5.712, year: 2008

  8. Gas chromatographic-mass spectrometric analysis of urinary volatile organic metabolites: Optimization of the HS-SPME procedure and sample storage conditions.

    Science.gov (United States)

    Živković Semren, Tanja; Brčić Karačonji, Irena; Safner, Toni; Brajenović, Nataša; Tariba Lovaković, Blanka; Pizent, Alica

    2018-01-01

    Non-targeted metabolomics research of human volatile urinary metabolome can be used to identify potential biomarkers associated with the changes in metabolism related to various health disorders. To ensure reliable analysis of urinary volatile organic metabolites (VOMs) by gas chromatography-mass spectrometry (GC-MS), parameters affecting the headspace-solid phase microextraction (HS-SPME) procedure have been evaluated and optimized. The influence of incubation and extraction temperatures and times, coating fibre material and salt addition on SPME efficiency was investigated by multivariate optimization methods using reduced factorial and Doehlert matrix designs. The results showed optimum values for temperature to be 60°C, extraction time 50min, and incubation time 35min. The proposed conditions were applied to investigate urine samples' stability regarding different storage conditions and freeze-thaw processes. The sum of peak areas of urine samples stored at 4°C, -20°C, and -80°C up to six months showed a time dependent decrease over time although storage at -80°C resulted in a slight non-significant reduction comparing to the fresh sample. However, due to the volatile nature of the analysed compounds, more than two cycles of freezing/thawing of the sample stored for six months at -80°C should be avoided whenever possible. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. LIQUID CHROMATOGRAPHIC / MASS SPECTROMETRIC DETERMINATION OF MORPHINE, CODEINE AND COCAINE IN HUMAN SERA USING A NEW INTERNAL SURFACE REVERSED PHASE COLUMN

    OpenAIRE

    Hattori, Hideki; Arinobu, Tetsuya; Iwai, Masae; Suzuki, Osamu; Seno, Hiroshi

    2003-01-01

    A new internal surface reversed phase column (Shim-pack MAYI-ODS) was used for analysis of morphine, codeine and cocaine in human sera by LC/MS/MS. The column enabled direct injection of crude biological samples without pretreatment realizing a rapid analytical procedure. Therecoveries of morphine, codeine and cocaine spiked into human sera were 50-60 %. The regression equations for morphine, codeine and cocaine in sera, using atropine as internal standard, showed good linearity in the ranges...

  10. Monolithic silica spin column extraction and simultaneous derivatization of amphetamines and 3,4-methylenedioxyamphetamines in human urine for gas chromatographic-mass spectrometric detection

    International Nuclear Information System (INIS)

    Nakamoto, Akihiro; Nishida, Manami; Saito, Takeshi; Kishiyama, Izumi; Miyazaki, Shota; Murakami, Katsunori; Nagao, Masataka; Namura, Akira

    2010-01-01

    A simple, sensitive, and specific method with gas chromatography-mass spectrometry was developed for simultaneous extraction and derivatization of amphetamines (APs) and 3,4-methylenedioxyamphetamines (MDAs) in human urine by using a monolithic silica spin column. All the procedures, such as sample loading, washing, and elution were performed by centrifugation. APs and MDAs in urine were adsorbed on the monolithic silica and derivatized with propyl chloroformate in the column. Methamphetamine-d 5 was used as an internal standard. The linear ranges were 0.01-5.0 μg mL -1 for methamphetamine (MA) and 3,4-methylenedioxymethamphetamine (MDMA) and 0.02-5.0 μg mL -1 for amphetamine (AP) and 3,4-methylenedioxyamphetamine (MDA) (coefficient of correlation ≥0.995). The recovery of APs and MDAs in urine was 84-94%, and the relative standard deviation of the intra- and interday reproducibility for urine samples containing 0.1, 1.0, and 4.0 μg mL -1 of APs and MDAs ranged from 1.4% to 13.6%. The lowest detection limit (signal-to-noise ratio ≥ 3) in urine was 5 ng mL -1 for MA and MDMA and 10 ng mL -1 for AP and MDA. The proposed method can be used to perform simultaneous extraction and derivatization on spin columns that have been loaded with a small quantity of solvent by using centrifugation.

  11. Monolithic silica spin column extraction and simultaneous derivatization of amphetamines and 3,4-methylenedioxyamphetamines in human urine for gas chromatographic-mass spectrometric detection

    Energy Technology Data Exchange (ETDEWEB)

    Nakamoto, Akihiro [Scientific Investigation Laboratory, Hiroshima Prefectural Police Headquarters, Kohnan 2-26-3, Naka-ku, Hiroshima 730-0825 (Japan); Nishida, Manami [Hiroshima University Technical Center, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8551 (Japan); Saito, Takeshi [Department of Emergency and Critical Care Medicine, Tokai University School of Medicine, Shimokasuya 143, Isehara, Kanagawa 259-1143 (Japan); Kishiyama, Izumi; Miyazaki, Shota [GL Sciences Inc., Sayamagahara 237-2, Iruma, Saitama 358-0032 (Japan); Murakami, Katsunori [Scientific Investigation Laboratory, Hiroshima Prefectural Police Headquarters, Kohnan 2-26-3, Naka-ku, Hiroshima 730-0825 (Japan); Nagao, Masataka [Department of Forensic Medicine, Graduate School of Biomedical Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8551 (Japan); Namura, Akira, E-mail: namera@hiroshima-u.ac.jp [Department of Forensic Medicine, Graduate School of Biomedical Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8551 (Japan)

    2010-02-19

    A simple, sensitive, and specific method with gas chromatography-mass spectrometry was developed for simultaneous extraction and derivatization of amphetamines (APs) and 3,4-methylenedioxyamphetamines (MDAs) in human urine by using a monolithic silica spin column. All the procedures, such as sample loading, washing, and elution were performed by centrifugation. APs and MDAs in urine were adsorbed on the monolithic silica and derivatized with propyl chloroformate in the column. Methamphetamine-d{sub 5} was used as an internal standard. The linear ranges were 0.01-5.0 {mu}g mL{sup -1} for methamphetamine (MA) and 3,4-methylenedioxymethamphetamine (MDMA) and 0.02-5.0 {mu}g mL{sup -1} for amphetamine (AP) and 3,4-methylenedioxyamphetamine (MDA) (coefficient of correlation {>=}0.995). The recovery of APs and MDAs in urine was 84-94%, and the relative standard deviation of the intra- and interday reproducibility for urine samples containing 0.1, 1.0, and 4.0 {mu}g mL{sup -1} of APs and MDAs ranged from 1.4% to 13.6%. The lowest detection limit (signal-to-noise ratio {>=} 3) in urine was 5 ng mL{sup -1} for MA and MDMA and 10 ng mL{sup -1} for AP and MDA. The proposed method can be used to perform simultaneous extraction and derivatization on spin columns that have been loaded with a small quantity of solvent by using centrifugation.

  12. Performance evaluation of a thermal desorption/gas chromatographic/mass spectrometric method for the characterization of waste tank headspace samples

    International Nuclear Information System (INIS)

    Ma, C.Y.; Skeen, J.T.; Dindal, A.B.; Bayne, C.K.; Jenkins, R.A.

    1997-01-01

    A thermal desorption/gas chromatography/mass spectrometry (TD/GC/MS) method was validated for the determination of volatile organic compounds collected on carbonaceous triple sorbent traps and applied to characterize samples of headspace gases collected from underground nuclear waste storage tanks at the U.S. Department of Energy's Hanford site, in Richland, WA. Method validation used vapor-phase standards generated from 25 target analytes, including alkanes, alkyl alcohols, alkyl ketones, alkylated aromatics, and alkyl nitriles. The target analytes represent a group of compounds identified in one of the most problematic tanks. TD/GC/MS was carried out with modified injectors. Performance was characterized based on desorption efficiency, reproducibility, stability, and linearity of the calibration, method detection limits, preanalytical holding time, and quality control limits for surrogate standard recoveries. Desorption efficiencies were all greater than 82%, and the majority of the analytes (23 out of 25) had reproducibility values less than 24% near the method detection levels. The method was applied to the analysis of a total of 305 samples collected from the headspaces of 48 underground waste storge tanks. Quality control procedures were implemented to monitor sampling and TD/GC/MS method. 33 refs., 2 figs., 4 tabs

  13. Monolithic silica spin column extraction and simultaneous derivatization of amphetamines and 3,4-methylenedioxyamphetamines in human urine for gas chromatographic-mass spectrometric detection.

    Science.gov (United States)

    Nakamoto, Akihiro; Nishida, Manami; Saito, Takeshi; Kishiyama, Izumi; Miyazaki, Shota; Murakami, Katsunori; Nagao, Masataka; Namura, Akira

    2010-02-19

    A simple, sensitive, and specific method with gas chromatography-mass spectrometry was developed for simultaneous extraction and derivatization of amphetamines (APs) and 3,4-methylenedioxyamphetamines (MDAs) in human urine by using a monolithic silica spin column. All the procedures, such as sample loading, washing, and elution were performed by centrifugation. APs and MDAs in urine were adsorbed on the monolithic silica and derivatized with propyl chloroformate in the column. Methamphetamine-d(5) was used as an internal standard. The linear ranges were 0.01-5.0 microg mL(-1) for methamphetamine (MA) and 3,4-methylenedioxymethamphetamine (MDMA) and 0.02-5.0 microg mL(-1) for amphetamine (AP) and 3,4-methylenedioxyamphetamine (MDA) (coefficient of correlation > or = 0.995). The recovery of APs and MDAs in urine was 84-94%, and the relative standard deviation of the intra- and interday reproducibility for urine samples containing 0.1, 1.0, and 4.0 microg mL(-1) of APs and MDAs ranged from 1.4% to 13.6%. The lowest detection limit (signal-to-noise ratio > or = 3) in urine was 5 ng mL(-1) for MA and MDMA and 10 ng mL(-1) for AP and MDA. The proposed method can be used to perform simultaneous extraction and derivatization on spin columns that have been loaded with a small quantity of solvent by using centrifugation. Copyright 2009 Elsevier B.V. All rights reserved.

  14. At-line gas chromatographic-mass spectrometric analysis of fatty acid profiles of green microalgae using a direct thermal desorption interface

    NARCIS (Netherlands)

    Blokker, P.; Pel, R.; Akoto, L.; Udo, A.; Brinkman, U.A.Th.; Vreuls, R.J.J.

    2002-01-01

    Thermally assisted hydrolysis and methylation¯gas chromatography (THM¯GC) is an important tool to analyse fatty acid in complex matrices. Since THM¯GC has major drawbacks such as isomerisation when applied to fatty acids in natural matrices, a direct thermal desorption (DTD) interface and an

  15. Dosimetric studies, spectrometric, radiographic, metallographic of a new argentinean seed of 125 I used in brachytherapy

    International Nuclear Information System (INIS)

    Pirchio, R.; Saravi, M.; Banchik, D.; Munoz, C.

    2006-01-01

    A new source of 125 I model Braquibac TM has been developed in Argentina for applications in interstitial brachytherapy. The AAPM Task Group 43 (TG-43) recommends that dosimetric characteristics of new sources of brachytherapy of Iodine-125 have been theoretically and experimentally determined before its clinical use. The objectives outlined in this work were the study of the design of the new seed, the calculation of dosimetric parameters and the photons spectra analysis. Its were carried out radiographic and metallographic studies to determine the physical characteristics of the source. For the realization of the dosimetric calculations it was used the Monte Carlo code MCNP5. Values of the radial dose function, g(r), of the constant of dose rate, Λ, of the function of anisotropy of two dimensions, F(r, θ), of the factor and constant of anisotropy its were obtained simulating the source in water according to the recommended methodology in TG-43. The constant of dose rate is similar to 0,880 ± 0,080 c Gy h -1 U -1 . The kerma in air rate of reference, S K , was calculated as 1,036 c Gy cm 2 h -1 mCi -1 simulating the seed in dry air. Its were carried out spectrometric studies using a semiconductor planar detector of HPGe (high purity germanium). Photons spectra showed characteristic x-rays of 125 I with energies of 27,20 keV, 27,47 keV, 31 keV and 31,70 keV gamma photons of 35,5 keV, and x-ray fluorescent coming from the silver nucleus of 22,10 keV, 24,94 keV and 25,45 keV. The angular dependence of the intensity of photons around the seed and in air it was analyzed with the planar detector. This was carried out to study the anisotropy in the photons flow due to variation in the thickness of the titanium wall and of the welding, movements of the silver tube inside the source and deposition of the radioactive material on the silver tube. (Author)

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

    International Nuclear Information System (INIS)

    Crews, H.M.; Eagles, J.; Mellon, F.A.; Luten, J.B.; McGaw, B.A.

    1994-01-01

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

  17. Study of non-validity of mixture rule near K-absorption edges by X-ray spectrometric technique

    International Nuclear Information System (INIS)

    Sharanabasappa; Chitralekha, A.; Kerur, B.R.; Anilkumar, S.

    2012-01-01

    X-ray spectrometric technique has been described to determine the X-ray mass attenuation coefficient, μ/ρ, of X-rays employing HPGe X-ray detector and radioactive sources. The photon intensity is measured by gating the channel of the spectrometer at FWHM/photo peak. Using the technique the 'best value' values of μ/ρ were obtained for those thicknesses which lie in the transmission (T) range 0.5 ≥ T ≥ 0.02. Total attenuation cross sections for other elements and lead compounds were measured at photon energies from 17 to 88 keV to study the Bragg's additivity law near the absorption edge of the lead. The measured values of mass attenuation coefficient values are compared with theoretical values obtained using Winxcom (programme). This study suggests that measured mass attenuation coefficient values at and near absorption edges differ from the theoretical value by about 17-23%. (author)

  18. Interaction of norfloxacin with bovine serum albumin studied by different spectrometric methods; displacement studies, molecular modeling and chemometrics approaches

    Energy Technology Data Exchange (ETDEWEB)

    Naseri, Abdolhossein, E-mail: a_naseri@tabrizu.ac.ir [Departments of Analytical Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz 51666-16471 (Iran, Islamic Republic of); Hosseini, Soheila [Departments of Analytical Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz 51666-16471 (Iran, Islamic Republic of); Rasoulzadeh, Farzaneh [Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz 51644-14766 (Iran, Islamic Republic of); Rashidi, Mohammad-Reza [Research Center for Pharmaceutical Nanotechnology, Tabriz University of Medical Sciences, Tabriz 51644-14766 (Iran, Islamic Republic of); Zakery, Maryam; Khayamian, Taghi [Department of Chemistry, College of Chemistry, Isfahan University of Technology, Isfahan 84154 (Iran, Islamic Republic of)

    2015-01-15

    Serum albumins as major target proteins can bind to other ligands leading to alteration of their pharmacological properties. The mechanism of interaction between norfloxacin (NFLX) with bovine serum albumin (BSA) was investigated. Fuorescence quenching of serum albumin by this drug was found to be a static quenching process. The binding sites number, n, apparent binding constant, K, and thermodynamic parameters were calculated at different temperatures. The distance, r, between donor, BSA, and acceptor, NFLX, was calculated according to the Forster theory of non-radiation energy transfer. Also binding characteristics of NFLX with BSA together with its displacement from its binding site by kanamycin and effect of common metal ions on binding constant were investigated by the spectroscopic methods. The conformational change in the secondary structure of BSA upon interaction with NFLX was investigated qualitatively from synchronous fluorescence spectra, Fourier Transform Infrared (FTIR) and circular dichroism (CD) spectrometric methods. Molecular docking studies were performed to obtain information on the possible residues involved in the interaction process and changes in accessible surface area of the interacting residues. The results showed that the conformation of BSA changed in the presence of NFLX. For the first time, displacement studies were used for this interaction; displacement studies showed that NFLX was displaced by phenylbutazon and ketoprofen but was not displaced by ibuprofen indicating that the binding site of NFLX on albumin was site I. In addition a powerful chemometrics method, multivariate curve resolution-alternating least square, was used for resolution of spectroscopic augmented data obtained in two different titration modes in order to extract spectral information regardless of spectral overlapping of components. - Highlights: • Interaction between norfloxacin and BSA is studied by spectral methods. • Chemometrics methods are used to

  19. Vaporization study on vanadium-oxygen solid solution by mass spectrometric method

    International Nuclear Information System (INIS)

    Banchorndhevakul, W.; Matsui, Tsuneo; Naito, Keiji

    1986-01-01

    The vapor pressures over vanadium-oxygen solid solution (0.001 ≤ O/V ≤ 0.145) were measured by mass-spectrometric method in the temperature range of 1,855 ∼ 2,117 K. The main vapor species were observed to be V(g) and VO(g). The vapor pressure of V(g) is higher than that of VO(g) over the solid solutions with all O/V ratios except for O/V = 0.145. The vapor pressure of V(g) is nearly independent of O/V ratio. The vapor pressure of VO(g) decreases with decreasing O/V ratio. The oxygen partial pressure was calculated as a function of temperature and O/V ratio from the vapor pressures of V(g) and VO(g), from which the partial molar enthalpy and entropy of oxygen in the solid solution were determined. The partial molar enthalpy of oxygen was observed to be independent of composition, suggesting the presence of very weak interaction between interstitial oxygens. The compositional dependence of the partial molar entropy of oxygen can be explained by assuming the occupation of the octahedral site in bcc vanadium lattice by the interstitial oxygens. The excess partial molar entropy of oxygen was compared with the value derived from the sum of the contributions from the volume expansion, electronic heat capacity and vibrational terms. (author)

  20. Spectrometric techniques 4

    CERN Document Server

    Vanasse, George A

    2013-01-01

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

  1. Electrospray ionization mass spectrometric investigations of [alpha]-dicarbonyl compounds--Probing intermediates formed in the course of the nonenzymatic browning reaction of l-ascorbic acid

    Science.gov (United States)

    Schulz, Anke; Trage, Claudia; Schwarz, Helmut; Kroh, Lothar W.

    2007-05-01

    A new method is presented which allows the simultaneous detection of various [alpha]-dicarbonyl compounds generated in the course of the nonenzymatic browning reaction initiated by thermal treatment of l-ascorbic acid, namely: glyoxal, methylglyoxal, diacetyl, 3-deoxy-l-pentosone, and l-threosoneE 3-Deoxy-l-threosone was successfully identified as a new C4-[alpha]-dicarbonyl structure for the first time in the degradation of Vitamin C by application of this non-chromatographic mass spectrometric approach. Moreover, a more detailed elucidation of the mechanistic scenario with respect to the oxidative and nonoxidative pathways is presented by using dehydro-l-ascorbic acid and 2,3-diketo-l-gulonic acid instead of l-ascorbic acid as a starting material. Furthermore, the postulated pathways are corroborated with the aid of 13C-isotopic labeling studies. The investigations were extended to baby food, and the successful detection of [alpha]-dicarbonyl compounds characteristic for Vitamin C degradation proved the matrix tolerance of the introduced method.

  2. Determination of itopride in human plasma by liquid chromatography coupled to tandem mass spectrometric detection: application to a bioequivalence study.

    Science.gov (United States)

    Lee, Heon-Woo; Seo, Ji-Hyung; Choi, Seung-Ki; Lee, Kyung-Tae

    2007-01-30

    A simple method using a one-step liquid-liquid extraction (LLE) with butyl acetate followed by high-performance liquid chromatography (HPLC) with positive ion electrospray ionization tandem mass spectrometric (ESI-MS/MS) detection was developed for the determination of itopride in human plasma, using sulpiride as an internal standard (IS). Acquisition was performed in multiple reaction monitoring (MRM) mode, by monitoring the transitions: m/z 359.5>166.1 for itopride and m/z 342.3>111.6 for IS, respectively. Analytes were chromatographed on an YMC C18 reverse-phase chromatographic column by isocratic elution with 1 mM ammonium acetate buffer-methanol (20: 80, v/v; pH 4.0 adjusted with acetic acid). Results were linear (r2=0.9999) over the studied range (0.5-1000 ng mL(-1)) with a total analysis time per run of 2 min for LC-MS/MS. The developed method was validated and successfully applied to bioequivalence studies of itopride hydrochloride in healthy male volunteers.

  3. Mass spectrometrical study of rare gas compositions and neutron capture effects in Yamato-74191 (L 3) Chondrite

    International Nuclear Information System (INIS)

    Takaoka, N.; Nagao, K.

    1980-01-01

    The unequilibrated hypersthene chondrite Yamato-74191 was studied mass spectrometrically for rare gases released at various temperatures. Cosmogenic gases dominate in He and Ne. The meteorite contains large amounts of trapped Ar, Kr and Xe, and radiogenic 40 Ar and 129 Xe. Cosmic-ray irradiation and K-Ar ages were determined. In addition to spallogenic components of Kr and Xe, isotopic excesses of 8 sup(O)Kr, 82 Kr, 128 Xe and 126 Xe relative to AVCC-Kr and -Xe were found. The ratio of 80 Kr-excess to 82 Kr-excess is 2.66 after correction for spallogenic Kr. A correlation between 128 Xe/ 132 Xe and 129 Xe/ 132 Xe was found. The 129 Xe/ 132 Xe ratio for trapped Xe in Yamato-74191 was determined as 1.12 +- 0.29 with the correlation plot. The excesses found in Yamato-74191 are best explained by epithermal neutron capture on Br and I, and by the 127 I(n,2nβ) 126 Xe reaction. Using neutron-produced 80 Kr, the neutron slowing-down density was estimated to be 0.14 +- 0.03 cm -3 sec -1 . A minimum mass and a preatmospheric radius was estimated to be 470 kg and 32 cm, respectively. (orig.)

  4. Mobile spectrometric laboratory

    International Nuclear Information System (INIS)

    Isajenko, K.A.; Lipinski, P.

    2002-01-01

    The article presents the Mobile Spectrometric Laboratory used by Central Laboratory for Radiological Protection since year 2000. The equipment installed in the Mobile Laboratory and its uses is described. The results of international exercises and intercalibrations, in which the Laboratory participated are presented. (author)

  5. Mass spectrometric quantification of salivary metanephrines-A study in healthy subjects

    NARCIS (Netherlands)

    Osinga, Thamara E.; Horst-Schrivers, van der Anouk N. A.; van Faassen, Martijn; Kerstens, Michiel N.; Dullaart, Robin P. F.; Pacak, Karel; Links, Thera P.; Kema, Ido P.

    Background: Determination of metanephrine (MN), normetanephrine (NMN), and 3-methoxytyramine (3-MT) in saliva may offer potential diagnostic advantages in diagnosing pheochromocytoma. Methods: In this preliminary study, we determined metanephrine concentrations in saliva of healthy subjects and the

  6. Study of radionuclides speciation with biological molecules of interest by spectrometric techniques

    International Nuclear Information System (INIS)

    Lourenco, V.

    2007-07-01

    Mechanisms of complexation and accumulation of the radionuclides at the cellular and molecular level are complex and poorly known because the studies on these subjects are scarce. Within the framework of this thesis, we studied the interactions of europium (analogue of trivalent actinides) and uranium (VI) (actinide) with biological molecules of interest: phyto-chelatins. Their role is to protect cells against intrusions from nonessential heavy metals (thus toxic). These proteins are likely to be implied in the mechanisms of sequestration of radionuclides in living organisms. However, their structure is complex, this is why, in order to better understand their reactivity, we extended our studies to lower entities which constitute them (amino acids and glutathione). We determined solution speciation (stoichiometry, structure) as well as the complexing constants associated with the formation of these species. These studies were undertaken by Time Resolved Laser induced Fluorescence (TRLIF), Electro-Spray Mass Spectrometry (ES-MS), Nuclear Magnetic Resonance (NMR), Fourier Transform Infra-Rouge spectroscopy (FTIR) and Extended X-ray Absorption Fine Structure Spectroscopy (EXAFS). The determination of the complexation constants enabled us to conclude that the complexing capacity of these molecules with respect to radionuclides was moderate (log 10 K 1 < 3, pH 3 or 6), the formed species are mononuclear with only one ligand molecule (1:1). The interaction is performed via oxygenated (hard) groups. The direct complexation of europium with phyto-chelatins at acidic pH was studied jointly by TRLIF and ES-MS. The complexing capacity of these molecules is much higher than that of GSH from which they result. In addition to studies undertaken on synthetic solutions reproducing the 'biological' conditions (pH close to neutrality, ionic strength 0.1 mol/L, etc), tests of cellular contamination were realized. The quantification of integrated europium showed that those are able to

  7. Lanthanum benzoyl acetonates: an IR and mass spectrometric study of the composition and structure

    International Nuclear Information System (INIS)

    Kostyuk, N.N.; Dik, T.A.; Tereshko, N.V.

    2005-01-01

    IR spectroscopy and mass spectrometry were used to study the structure of lanthanum chelates of benzoyl acetone (1-phenyl-1,3-butadione, HBA) of the following compositions: La(BA) 3 · EtOH, La(BA) 2 , La(BA) 2 · CH 3 CN, and La(BA) 2 · HDA, where EtOH = ethanol, HDA = nonadecanoic acid. It is demonstrated that a quasi-aromatic metalloring is formed in lanthanum chelates studied. Stable metal-containing fragments of the molecular ions of lanthanum bis- and tris-benzoylacetonate were identified [ru

  8. Study of radionuclides speciation with biological molecules of interest by spectrometric techniques

    International Nuclear Information System (INIS)

    Lourenco, V.

    2007-07-01

    Mechanisms of complexation and accumulation of the radionuclides at the cellular and molecular level are complex and poorly known because the studies on these subjects are scarce. Within the framework of this thesis, we studied the interactions of these cations with biological molecules of interest. We chose to focus on an actinide: uranium (VI) as well as europium as an analogue of trivalent actinides. The selected biological molecules are the phyto-chelatins: their role is to protect cells against intrusions from nonessential heavy metals (thus toxic). These proteins are likely to be implied in the mechanisms of sequestration of radionuclides in living organisms. However, their structure is complex, this is why, in order to better include/understand their reactivity, we extended our studies to lower entities which constitute them (amino acid: glycine, glutamic acid and cysteine; polypeptides: glutathione reduced and oxidized forms). In particular, we determined solution speciation (stoichiometry, structure) as well as the complexing constants associated with the formation with these species. These studies were undertaken by Time Resolved Laser induced Fluorescence (TRLIF), Electro-Spray-Mass Spectrometry (ES-MS), Nuclear Magnetic Resonance (NMR), Fourier Transform Infra-Rouge spectroscopy (FTIR) and Extended X-ray Absorption Fine Structure Spectroscopy (EXAFS).The determination of the complexation constants enabled us to conclude that the complexing capacity of these molecules with respect to radionuclides was moderate (log 10 K 1 ≤ 3, pH 3 or 6), the formed species are mononuclear with only one ligand molecule (1:1). The interaction is performed via oxygenated (hard) groups. The direct complexation of europium with phyto-chelatins at acidic pH was studied jointly by TRLIF and ES-MS. The complexing capacity of these molecules is much higher than that of GSH from which they result. The interaction of europium with metallothioneins is, on the contrary, lower than

  9. Mass spectrometric studies of bimolecular reactions in a selected ion flow tube (SIFT)

    International Nuclear Information System (INIS)

    Shul, R.J.; Upschulte, B.L.; Passarella, R.; Keesee, R.G.; Castleman, A.W.

    1985-01-01

    The rate coefficients for a number of thermal energy charge transfer reactions have been obtained with a selected ion flow tube (SIFT). The reactions studied involve Ar + and Ar 2 + with a variety of neutral molecules including: O 2 , CS 2 , CO 2 , SO 2 , H 2 S, NH 3 , and SF 6 . Such reactions have been of long-standing interest in the field of gas-phase ion-molecule chemistry from both a practical and fundamental point of view. Consideration of charge transfer reactions as possible sources of chemical lasers and their role in ionospheric and interstellar chemistry account for much of the interest. Fundamentally, the mechanism involved in these reactions has yet to be definitively established. The consumption deposition of energy into internal modes and translational degrees of freedom in such reactions has also been a topic of considerable debate. The apparatus consists of five main components: an ion source, SIFT quadrupole, ion injector, flow tube, and a mass spectrometer detection system. Ions formed in a high pressure source leak into a SIFT quadrupole where they are mass selected. The primary ion of interest is then injected into the flow tube where reactions are studied. Once in the flow tube the ions are carried downstream by an inert buffer gas, either argon, nitrogen, or helium in the present study. Neutral reactant gas is added through a reactant gas inlet (RGI) at an appropriate location downstream in the flow tube, and allowed to react with the injected ions. Ions on the flow tube axis are sampled through a 1 mm orifice where they are mass analyzed by a second quadrupole mass spectrometer and detected with a channeltron electron multiplier

  10. Mass-spectrometric study of volatile uranyl β-diketonates and their adducts

    International Nuclear Information System (INIS)

    Adamov, V.M.; Belyaev, B.N.; Berezinskij, S.O.; Sidorenko, G.V.; Suglobov, D.N.

    1985-01-01

    The mass spectra of a number of uranyl β-diketonates containing methyl, trifluoromethyl and tert-butyl substituents in β-diketonate anion, and their adducts are measured. The form of the unsolvated β-diketonates and their adducts in gas phase is studied. The ways of fragmentation of uranyl β-diketonates and their adducts are investigated. The data concerning the thermal and chemical side reactions proceeding with uranyl β-diketonates and their addicts in an ion source are obtained. The mass spectra of the samples of neptunyl and plutonyl β-diketonate adducts synthesized for the first time are measured

  11. Quadrupole type mass spectrometric study of the abstraction reaction between hydrogen atoms and ethane.

    Science.gov (United States)

    Bayrakçeken, Fuat

    2008-02-01

    The reactions of photochemically generated deuterium atoms of selected initial translational energy with ethane have been investigated. At each initial energy the relative probability of the atoms undergoing reaction or energy loss on collision with ethane was investigated, and the phenomenological threshold energy was measured as 30+/-5kJmol(-1) for the abstraction from the secondary C-H bonds. The ratio of relative yields per bond, secondary:primary was approximately 3 at the higher energies studied. The correlation of threshold energies with bond dissociation energies, heats of reaction and activation energies is discussed for abstraction reactions with several hydrocarbons.

  12. Matrix isolation-infrared and mass spectrometric studies of high-temperature molecules

    International Nuclear Information System (INIS)

    Dickinson, S.

    1987-08-01

    Matrix isolation-infrared spectroscopy and mass spectrometry have been developed at AEE Winfrith to study the high-temperature vapour species which could be generated during a hypothetical severe reactor accident. The principles of the techniques and the instruments are described in detail, and examples of their application to specific systems discussed. Although these examples refer to high-temperature chemical species which are relevant to reactor safety assessments, the techniques are equally applicable to other processes where the characterisation of transient vapour-phase species is required. (author)

  13. Spectrometric techniques application to study of environmental contamination levels in south Shetland Antarctic

    International Nuclear Information System (INIS)

    Vera Tartaglia, C.; Camarota, R.; Costa, V.

    1993-01-01

    The methodology for studying the behaviour of the toxic pollutant metals (Hg, Pb, Cd, Cr) in the South Shetland region is presented here, toxic pollutants are caused by the urban and industrial activity at the Southern hemisphere and they are pressured to be incorporated to the region though atmospheric transport processes the Cs 137 (refI) was used as a tracing element, which was freed and dispersed in the atmosphere as a result of nuclear bombs testing. During the austral summer samples from ground, sediments, atmospheric and glacier were extracted.

  14. Mass-spectrometric and optimal study of products from the laser ablated PbTe(Ga)

    International Nuclear Information System (INIS)

    Mikhajlov, V.A.; Putilin, F.N.; Trubnikov, D.N.

    1994-01-01

    The products of evaporation (p=10 -7 Torr) of a PbTe(Ga) target ablated by the Nd 3+ : YA laser (λ=1.08 μm, τ=15 ns, w=0.47-4.8 Jxcm -2 ) have been studied using quadrupole mass spectrometry and optical spectroscopy. The neutral Pb, Te, Ga, Te 2 , PbTe and the singly charged ions of Pb, Te, Ga have been detected by mass spectrometry. The lines of Pb 1 , Pb 2 , Te 2 and Ga 1 have been observed in the region of 340-760 nm of the emission spectra, the lines of Pb 3 and Te 3 were absent. The kinetic energy of the ions has been estimated using the ion optics system decelerated and focused ions with the selected energy

  15. Vaporization study on nonstoichiometric NbOsub(2+-x) by mass-spectrometric method

    International Nuclear Information System (INIS)

    Matsui, T.; Naito, K.

    1981-01-01

    The vapor pressures over nonstoichiometric NbOsub(2+-x)(s) (1.972 2 (g) and NbO(g) over nonstoichiometric NbOsub(2+-x), from which the partial molar enthalpies and entropies of oxygen were calculated as a function of O/Nb composition. The composition dependence of the partial molar enthalpy and entropy obtained suggested the existence of some kind of short-range ordering in the nonstoichiometric Nbsub(2+-x) (s) phase. The enthalpies of formation of nonstoichiometric NbOsub(2+-x) (s) were also determined as a function of composition by combining the partial molar enthalpies of oxygen with the enthalpy of formation of stoichiometric NbOsub(2.000) (s). The phase diagram around NbOsub(2+-x) at high temperatures was determined from the vaporization study. (orig.)

  16. A laser photofragmentation time-of-flight mass spectrometric study of acetophenone at 193 and 248 nm

    Science.gov (United States)

    Zhao, H.-Q.; Cheung, Y.-S.; Liao, C.-L.; Liao, C.-X.; Ng, C. Y.; Li, Wai-Kee

    1997-11-01

    The photodissociation of acetophenone (C6H5COCH3) at 193 and 248 nm has been studied using the time-of-flight mass spectrometric technique. For hν=193 nm, two major primary channels, C6H5COCH3+hν→C6H5CO+CH3 [channel (1)] and C6H5+CH3CO [channel (2)], are observed with comparable cross sections. Data analysis shows that ≈30%-50% of primary C6H5CO and CH3CO radicals further decomposes, yielding secondary products C6H5+CO and CH3+CO, respectively. The translational energy release measurements indicate that for both channels (1) and (2) at 193 nm, ≈25%-30% of the available energy is channeled into kinetic energies of the primary photofragments. Measurements at hν=248 nm reveal that the branching ratio of channel (2) to channel (1) is ≈0.01. For channel (1) at hν=248 nm, ≈42% of the available energy is directed as the kinetic energy of the photofragments. The observed maximum kinetic energy release for channel (1) at 248 nm yields a value of 85.0±2.2 kcal/mol for the C6H5CO-CH3 bond dissociation energy at 0 K (D0). The photofragment angular distributions are found to be isotropic for both channels (1) and (2) at hν=193 nm and for channel (1) at hν=248 nm. A minor photodissociation channel C6H5COCH3+hν→C6H5CH3+CO is identified at both hν=193 and 248 nm. The energetics for the dissociation reactions of acetophenone have also been investigated using ab initio Gaussian-2-type procedures. The heats of formation at 0 K (ΔfH°0) for C6H5CO and C6H5 calculated using the isodesmic reaction scheme are 33.9±1.3 and 87.6±1.0 kcal/mol, respectively. These results suggest that the literature ΔfH°0 values for C6H5CO and C6H5 are likely to be low by 3-4 kcal/mol. These theoretical ΔfH° values for C6H5CO and C6H5 yield a theoretical D0(C6H5CO-CH3) value of 85.1±1.4 kcal/mol, which is in excellent accord with the experimental results obtained in the present study.

  17. Thermogravimetric-mass spectrometric study on the evolution of nitrogen compounds during coal devolatilisation

    Energy Technology Data Exchange (ETDEWEB)

    Arenillas, A.; Rubiera, F.; Pevida, C.; Pis, J.J. [Department of Energy and Environment, Instituto Nacional del Carbon, CSIC, Apartado 73, 33080 Oviedo (Spain)

    2002-10-01

    Emissions of nitrogen oxides during coal combustion are a major environmental problem. The chemically bound nitrogen in fuel accounts for up to 80% of total NO{sub x} emissions. In this respect, fundamental studies are needed to clarify the mechanisms and to identify the different species that are precursors in the formation of the NO{sub x}. Mass spectrometry (MS) has been used for decades as a successful technique in evolved gas analysis. However, MS is normally used to identify typical volatile compounds formed during coal pyrolysis (i.e. H{sub 2}, CH{sub 4}, CO, CO{sub 2} and H{sub 2}O) but very few works on the detection by MS of nitrogen compounds during coal devolatilisation can be found. In this work, the possibility of detecting different nitrogen compounds by means of thermogravimetric-MS during the temperature-programmed pyrolysis of coal was evaluated. Interferences in the N-compounds MS signals were determined. The use of model compounds provided additional information on the MS response factors of the volatile compounds produced.

  18. Development of a Mass Spectrometric Method for Pharmacokinetic Study of Trastuzumab

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Nam Young; Choi, Jin Nyoung; Kang, Jeong Won; Choi, Do Young; Kim, Kwang Pyo [Kyung Hee Univ., Yongin (Korea, Republic of); Park, Gyutae [CKD Research Institute, Yongin (Korea, Republic of)

    2014-06-15

    The HPLC-MS/MS method described here is a simple, rapid and specific method for determining the concentration of biologics in mouse serum. This method was validated for the quantification trastuzumab in ICR mice serum. Although the ELISA method is available for the pharmacokinetics study for trastuzumab, but these methods require development of the target specific antibodies. Generally, the development of the target specific antibodies for quantification is time consuming and expensive. In contrast, MRM-based method does not need antibodies for quantification. The therapeutic monoclonal antibody drug Trastuzumab (INN; trade name Herceptin) is widely used for treating metastatic breast cancer patients with overexpression of HER2 on the tumor. Trastuzumab is a representative target therapeutics as a monoclonal antibody that selectively binds with high affinity to the extracellular domain of the human epidermal growth factor receptor 2 protein, HER2. HER2 is amplified or over-expressed in about 20% to 30% of patients with breast cancer and is associated with aggressive disease. Trastuzumab has an inhibitory effect on the overexpression of HER2 receptor, thereby it has been used in treating breast cancer, and also gastric cancer.

  19. Thermogravimetric-Mass Spectrometric Study of the Pyrolysis Behavior of PVC

    Institute of Scientific and Technical Information of China (English)

    SUN Qing-lei; SHI Xin-gang; LIN Yun-liang; ZHU He; WANG Xiao; CHENG Chuan-ge; LIU Jian-hua

    2007-01-01

    The pyrolysis characteristics of PVC were systematically investigated using a Netzschne TG thermo-balance coupled to a quadrupole mass spectrometer. The pyrolysis conditions were 0.1 MPa of Ar, a heating rate of 10 ℃/min and a final temperature of 1000 ℃. Both the thermogravimetric properties and the simultaneous evolution of gaseous products during pyrolysis were studied. The TG/DTG results showed that as the pyrolysis temperature increases the weight loss and weight loss rate of PVC increases. Near 412 ℃ the weight loss rate attained its peak value. At higher temperatures the rate of loss gradually decreases. The gases evolved during thermogravimetric analysis were analyzed by a mass spectrometer, monitoring the relative intensity of HCl, C6H6, light hydrocarbon and chlorine-containing gases. The evolution curves showed that HCl, C6H6, light hydrocarbon and chlorine-containing gases all peak at about 416 ℃. This is consistent with the fact that the weight loss curves also peak at about 412 ℃. The extensive HCl evolution is consistent with the high chlorine content of PVC. The formation of these gases can be explained by considering these reactions: dehydrochlorination, intramolecular cyclization and the addition of HCl to unsaturated hydrocarbons.

  20. Mass spectrometric study of vaporization of (U,Pu)O2 fuel simulating high burnup

    International Nuclear Information System (INIS)

    Maeda, Atsushi; Ohmichi, Toshihiko; Fukushima, Susumu; Handa, Muneo

    1985-08-01

    The vaporization behavior of (U,Pu)O 2 fuel simulatig high burnup was studied in the temperature range of 1,573 -- 2,173 K by high temperature mass spectrometry. The phases in the simulated fuel were examined by X-ray microprobe analysis. The relationship between chemical form and vaporization behavior of simulated fission product elements was discussed. Pd, Sr, Ba, Ce and actinide-bearing vapor species were observed, and it was clarified that Pd vapor originated from metallic inclusion and Sr and Ce vapors, from mixed oxide fuel matrix. The vaporization behavior of the actinide elements was somewhat similar to that of hypostoichiometric mixed oxide fuel. The behavior of Ba-bearing vapor species changed markedly over about 2,000 K. From the determination of BaO vapor pressures over simulated fuel and BaZrO 3 , it was revealed thermodynamically that the transformation of the chemical form of Ba about 2,000 K, i.e., dissolution of BaZrO 3 phase into fuel matrix, might be the reason of the observed vapor pressure change. (author)

  1. Interactions of nucleobases with alkali earth metal cations--electrospray ionization mass spectrometric study.

    Science.gov (United States)

    Frańska, Magdalena

    2007-01-01

    Interactions of nucleobases with alkali earth metal cations have been studied by electrospray ionization mass spectrometry (ESI-MS). Nucleobases containing at least one oxygen atom form stable complexes with alkali earth metal cations. This phenomenon can be explained on the grounds of the well known theory of hard and soft acids and bases. Uracil and thymine make complexes only when in their deprotonoted forms. The cations of great radii (Sr(2+), Ba(2+)) are more prone to form complexes of stoichiometry 1:1 with uracil and thymine than the cations of small radii (Mg(2+), Ca(2+)). On the other hand, Mg(2+) forms complexes of stoichiometry 2:1 and 3:2 with uracil and thymine. Gas-phase stabilities of the 1:1 complexes are higher for the cations of small radii, in contrast to the solution stabilities. For cytosine and 9- methylhypoxantine the 1:1 complexes of their deprotonated forms are observed at higher cone voltage as a result of HCl molecule loss from the complexes containing the counter ion (Cl(-)). In solution, more stable complexes are formed with metal cations of low radii. Gas-phase stability of the complexes formed by deprotonated 9- methyl-hypoxantine increases with increasing metal cation radius.

  2. Studying of isotope structure of uranium by alpha-spectrometric method

    International Nuclear Information System (INIS)

    Sattarov, G.S.; Muzafarov, A.M.; Petukhov, O.F.; Petrenko, V.Z.

    2004-01-01

    Full text: The knowledge of isotope structure of uranium in waters, in minerals and in finished goods gives the helpful information on the radiation and nuclear-physical processes occurring in natural environments. Besides, customers put a question before uranium producing enterprises on the control of limiting concentration of an isotope 234 U in finished goods (uranium protoxide-oxide). For these reasons studying and development of techniques of definition of isotope structure of uranium is an actual task. In this connection for researches alpha - spectrometers 'PROGRESS-ALPHA' produced by R and D 'DOZE' Russia and firms 'Canberra' the USA were used. The isotope structure of uranium ( 234 U, 235 U, 238 U) was determined on a known ratio 234 U/ 238 U, which is equal to 53,41micrograms/gram. Identification of isotopes carried out by 4198 keV ( 235 U), 4395 keV ( 234 U) and 4773 keV ( 238 U). The technique of radiochemical preparation of samples to the analysis included: clearing of organic chemistry and preventing natural isotopes; drawing by a method electrolytic sedimentation on a metal substrate (d=24mm) an active stain, the area 4,5 cm 2 , with isotropy distribution of ions 234 U, 235 U, 238 U. As standards, the international and All-Russian standards with known contents 234 U were used. The isotope structure of uranium in uranium protoxide-oxide, chemical concentrates, technological solutions is determined. Infringements of isotope balance 234 U/ 238 U on separate sites of fulfilled uranium deposits and in technological products are found out

  3. Thermal Emission of Alkali Metal Ions from Al30-Pillared Montmorillonite Studied by Mass Spectrometric Method.

    Science.gov (United States)

    Motalov, V B; Karasev, N S; Ovchinnikov, N L; Butman, M F

    2017-01-01

    The thermal emission of alkali metal ions from Al 30 -pillared montmorillonite in comparison with its natural form was studied by mass spectrometry in the temperature range 770-930 K. The measurements were carried out on a magnetic mass spectrometer MI-1201. For natural montmorillonite, the densities of the emission currents ( j ) decrease in the mass spectrum in the following sequence (T = 805 K, A/cm 2 ): K + (4.55 · 10 -14 ), Cs + (9.72 · 10 -15 ), Rb + (1.13 · 10 -15 ), Na + (1.75 · 10 -16 ), Li + (3.37 · 10 -17 ). For Al 30 -pillared montmorillonite, thermionic emission undergoes temperature-time changes. In the low-temperature section of the investigated range (770-805 K), the value of j increases substantially for all ions in comparison with natural montmorillonite (T = 805 K, A/cm 2 ): Cs + (6.47 · 10 -13 ), K + (9.44 · 10 -14 ), Na + (3.34 · 10 -15 ), Rb + (1.77 · 10 -15 ), and Li + (4.59 · 10 -16 ). A reversible anomaly is observed in the temperature range 805-832 K: with increasing temperature, the value of j of alkaline ions falls abruptly. This effect increases with increasing ionic radius of M + . After a long heating-up period, this anomaly disappears and the ln j - 1/ T dependence acquires a classical linear form. The results are interpreted from the point of view of the dependence of the efficiency of thermionic emission on the phase transformations of pillars.

  4. Thermal Emission of Alkali Metal Ions from Al30-Pillared Montmorillonite Studied by Mass Spectrometric Method

    Directory of Open Access Journals (Sweden)

    V. B. Motalov

    2017-01-01

    Full Text Available The thermal emission of alkali metal ions from Al30-pillared montmorillonite in comparison with its natural form was studied by mass spectrometry in the temperature range 770–930 K. The measurements were carried out on a magnetic mass spectrometer MI-1201. For natural montmorillonite, the densities of the emission currents (j decrease in the mass spectrum in the following sequence (T = 805 K, A/cm2: K+ (4.55 · 10−14, Cs+ (9.72 · 10−15, Rb+ (1.13 · 10−15, Na+ (1.75 · 10−16, Li+ (3.37 · 10−17. For Al30-pillared montmorillonite, thermionic emission undergoes temperature-time changes. In the low-temperature section of the investigated range (770–805 K, the value of j increases substantially for all ions in comparison with natural montmorillonite (T = 805 K, A/cm2: Cs+ (6.47 · 10−13, K+ (9.44 · 10−14, Na+ (3.34 · 10−15, Rb+ (1.77 · 10−15, and Li+ (4.59 · 10−16. A reversible anomaly is observed in the temperature range 805–832 K: with increasing temperature, the value of j of alkaline ions falls abruptly. This effect increases with increasing ionic radius of M+. After a long heating-up period, this anomaly disappears and the lnj-1/T dependence acquires a classical linear form. The results are interpreted from the point of view of the dependence of the efficiency of thermionic emission on the phase transformations of pillars.

  5. Emission spectrometric isotope analyzer

    International Nuclear Information System (INIS)

    Mauersberger, K.; Meier, G.; Nitschke, W.; Rose, W.; Schmidt, G.; Rahm, N.; Andrae, G.; Krieg, D.; Kuefner, W.; Tamme, G.; Wichlacz, D.

    1982-01-01

    An emission spectrometric isotope analyzer has been designed for determining relative abundances of stable isotopes in gaseous samples in discharge tubes, in liquid samples, and in flowing gaseous samples. It consists of a high-frequency generator, a device for defined positioning of discharge tubes, a grating monochromator with oscillating slit and signal converter, signal generator, window discriminator, AND connection, read-out display, oscillograph, gas dosing device and chemical conversion system with carrier gas source and vacuum pump

  6. Spectrometric assembly for portable installations

    International Nuclear Information System (INIS)

    Kluger, A.; Popescu, C.

    1997-01-01

    The components of the portable spectrometric assembly are: - the detecting probe with Na I(Tl) crystal and air-tight case of industrial type; - a microcomputer; - a unit of analogical processing of the signal from the detecting probe; - a single-channel analyzer with adjustable threshold; - commands and display module; - a source of high voltage; - an electrical supply battery. The device uses the method of gamma photons detection in energetic windows. Through theoretical and experimental studies carried out during the prototype development phase, the superiority of this method has been proved as compared with the installations which make use of the classical principle of photon integral detection. The achieved prototype has a basic program enabling the setting of all working parameters (measuring time, discriminating thresholds, discriminators operating conditions, etc.). Through the included interface RS232 it is possible to transmit the data to a more powerful computer in order to continually process the results. The spectrometric assembly, realized on the basis of micro-computers, can be used in a wide range of applications: measurement of thickness and erosion of walls and tubes, measurement of level in closed containers, of soil density, etc. The adjustment for specific application is performed only through a program modification. (authors)

  7. Spectrometric techniques 2

    CERN Document Server

    Vanasse, George A

    2013-01-01

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

  8. Theoretical study and construction of a multichannel {beta} spectrometer with uniform magnetic field; Etude et realisation d'un spectrometre {beta} multivoies a champ magnetique uniforme

    Energy Technology Data Exchange (ETDEWEB)

    Schussler, F [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1965-09-01

    After a brief survey of the interest of a multichannel beta spectrometer for studying decay schemes of short lived nuclides (30 seconds minimum, the theoretically well known characteristics of uniform magnetic field analyser (image of a large source, transmission and resolution) are briefly remembered. In the second part, the apparatus built as a result of these calculations is described. This apparatus allows the determination of beta spectra by simultaneous determination of the beta spectra in coincidence with four gamma rays predetermined in the gamma spectrum of the studied nuclide. Finally, in the last part, the experimental characteristics of the spectrometer (calibration in energy and transmission) and the first measurement of beta spectra ({sup 155}Sm) and of coincidences ({sup 24}Na), are given. (author) [French] Apres avoir brievement souligne l'interet pratique que presente un spectrometre multivoies pour l'etude des schemas de desintegration des corps radioactifs de courtes periodes (30 secondes au maximum), l'auteur effectue un rappel des caracteristiques theoriques bien connues d'un analyseur magnetique a champ uniforme (image d'une source etendue) calcul de la transmission et du pouvoir de resolution. Une deuxieme partie est consacree a la description de l'appareil realise d'apres ces calculs. Cet appareil permet le releve des spectres beta par detection, simultanee de dix groupes d'electrons d'energies differentes; il permet egalement le releve simultane des spectres beta en coincidence avec quatre rayonnements gammas preselectionnes a l'avance dans le spectre gamma du corps etudie. Dans une derniere partie enfin, sont donnees les caracteristiques experimentales du spectrometre (etalonnage en energie et en transmission) ainsi que les premiers resultats des etudes de spectre beta ({sup 155}Sm) et de coincidence ({sup 24}Na). (auteur)

  9. Theoretical study, and construction, of a spherical electrostatic beta spectrometer; Etude theorique et realisation d'un spectrometre beta electrostatique spherique

    Energy Technology Data Exchange (ETDEWEB)

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

    1964-03-15

    After a literature survey showing the importance of an electrostatic spectrometer with spherical electrodes for studying disintegration processes, the theoretical characteristics of such an apparatus are derived (determination of the trajectory equations calculation of the transmission and of the resolving power the case of a point source and of an extended source). The apparatus built as a result of these calculations is described. The electrostatic field distribution outside the electrodes is derived. As well as giving electron spectra ({beta} disintegration and conversion electrons) the apparatus make s it possible to study e-{gamma}, e-{beta}, e-e-{gamma} and e-e-{beta} coincidences. In the last part are given experimental characteristics and the results of the first measurements made on conversion electron spectra ({sup 161}Tb, {sup 151}Pm, {sup 155}Eu) and on coincidences ({sup 170}Tm) using this spectrometer. (author) [French] Apres une etude bibliographique montrant l'interet que presente un spectrometre electrostatique a electrodes spheriques pour l'etude des schemas de desintegration, l'auteur etablit les caracteristiques theoriques d'un tel appareil (determination de l'equation des trajectoires calcul de la transmission et du pouvoir de resolution cas d'une source ponctuelle et d'une source etendue). On decrit l'appareil realise d'apres ces calculs. On etablit la repartition du champ electrostatique a l'exterieur des electrodes. Outre le trace des spectres d'electrons (desintegration {beta} et electrons de conversion), l'appareil permet l'etude de coincidences e-{gamma}, e-{beta}, e-e-{gamma} and e-e-{beta}. Dans la derniere partie, sont donnees les caracteristiques experimentales et les premieres etudes de spectres d'electrons de conversion ({sup 161}Tb, {sup 151}Pm, {sup 155}Eu) et de coincidences ({sup 170}Tm) faites a l'aide de ce spectrometre. (auteur)

  10. Liquid-liquid extraction/headspace/gas chromatographic/mass spectrometric determination of benzene, toluene, ethylbenzene, (o-, m- and p-)xylene and styrene in olive oil using surfactant-coated carbon nanotubes as extractant.

    Science.gov (United States)

    Carrillo-Carrión, Carolina; Lucena, Rafael; Cárdenas, Soledad; Valcárcel, Miguel

    2007-11-09

    BTEX-S compounds are widely distributed in the environment and can be present in different foodstuffs, including olive oil. Taking into account the risks of the exposure to these compounds, analytical methods for their determination in different matrices are mandatory. In this paper, the use of surfactant-coated multiwalled carbon nanotubes as additive in liquid-liquid extraction is applied for the determination of single-ring aromatic compounds in olive oil samples. After sample treatment, the aqueous extracts are subsequently analyzed by headspace/gas chromatography/mass spectrometry allowing the determination of BTEX-S within ca. 15 min. Each stage of the proposed LLE/HS/GC/MS configuration involves a selectivity enhancement avoiding the interference of other compounds of the sample matrix. Limits of detection were in the range 0.25 ng mL(-1) (obtained for ethylbenzene) and 0.43 ng mL(-1) (for benzene). The repeatability of the proposed method expressed as RSD varied between 1.9% (styrene) and 3.3% (benzene) (n=11).

  11. Vaporization study on vanadium monoxide and two-phase mixture of vanadium and vanadium monoxide by mass-spectrometric method

    International Nuclear Information System (INIS)

    Banchorndhevakul, W.; Matsui, Tsuneo; Naito, Keiji

    1986-01-01

    The vapor pressures over single phase vanadium monoxide VO 1.022 (s) and the two-phase mixture of vanadium metal (β phase) and vanadium monoxide were measured by mass-spectrometric method in the temperature range of 1,803 ∼ 1,990 and 1,703 ∼ 1,884 K, respectively. The main gas species over both systems were found to be VO(g) and V(g). The vapor pressure of VO(g) over the two-phase mixture of V(s) and VO(s) was a little lower than that over single phase VO(s). The vapor pressure of V(g) over the two-phase mixture was nearly equal to that over single phase. From the vapor pressure data, the enthalpies of vaporization, the enthalpies of formation for VO(g) and V(g) and the dissociation energy of VO(g) were determined. The oxygen partial pressure was calculated as a function of temperature from the vapor pressures of VO(g) and V(g), from which the partial molar enthalpies and entropies of oxygen in both systems were obtained. (author)

  12. A spectrometer using semi-conductor detectors; study and applications (1963); Spectrometre utilisant les detecteurs a semi-conducteur: etudes et applications (1963)

    Energy Technology Data Exchange (ETDEWEB)

    Roux, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1963-07-01

    The low average energy, 2.5 to 3.5 eV, required to produce one hole-electron pair in a semiconductor allows an accurate measurement of the energy of the ionizing particles. A high resolution spectrometer has been built using semiconductor detectors. The limit of resolution, due to electronics associated to the detector, to the detector itself and to the source of particles is studied here. The present practical limit of resolution of the spectrometer is 1700 elementary electric charges (full width at half maximum of a ray of a spectrum) or 6 keV in terms of energy lost by a particle in a silicon detector. The physical resolution usually obtained is 20 keV (0.33 per cent) with {alpha} particles of the {sup 212}Bi (6.087 MeV). It depends a lot of the kind of detector used. Some results, concerning the background of the detectors and limit of measurements for low energies are given. Various applications are presented: spectrometry {beta}, spectrometry {gamma} and X, spectrometry of mixtures of {alpha} radioactive elements, collection of {alpha} spectra. (author) [French] La faible energie moyenne, 2,5 a 3,5 eV, necessaire pour produire une paire electron-trou dans un semi-conducteur, permet une mesure precise de l'energie des particules ionisantes. Un spectrometre a haute resolution a ete construit utilisant des detecteurs a semi-conducteur. La limitation en resolution due a l'electronique associee au detecteur, au detecteur lui-meme et a la source de particules, est etudiee. La resolution pratique limite actuelle du spectrometre est 1700 charges electriques elementaires (largeur a mi-hauteur d'une raie de spectre) ou 6 keV exprimee en energie perdue par une particule dans un detecteur au silicium. La resolution physique couramment obtenue est de 20 keV (0,33 pour cent) pour les particules {alpha} du bismuth 212 (6,087 MeV). Elle depend beaucoup du detecteur utilise. Quelques resultats sont donnes concernant le mouvement propre des detecteurs et la limitation des

  13. NZG 201 portable spectrometric unit

    International Nuclear Information System (INIS)

    Jursa, P.; Novakova, O.; Slezak, V.

    The NZG 201 spectrometric unit is a portable single-channel processing unit supplied from the mains or a battery which allows the qualitative and quantitative measurement of different types of ionizing radiation when connected to a suitable detection unit. The circuit layout and the choice of control elements makes the spectrometric unit suitable for use with scintillation detector units. The spectrometric unit consists of a pulse amplifier, an amplitude pulse analyzer, a pulse counter, a pulse rate counter with an output for a recorder, a high voltage source and a low voltage source. The block diagram is given. All circuits are modular and are mounted on PCB's. The apparatus is built in a steel cabinet with a raised edge which protects the control elements. The linear pulse amplifier has a maximum gain of 1024, the pulse counter has a maximum capacity of 10 6 -1 imp and time resolution better than 0.5 μs. The temperature interval at which the apparatus is operational is 0 to 45 degC, its weight is 12.5 kg and dimensions 36x280x310 mm, energy range O.025 to 2.5 MeV, for 137 Cs the energy resolution is 8 to 10%. The spectrometric unit NZG 2O1 may, with regard to its parameters, number and range of control elements, be used as a universal measuring unit. (J.P.)

  14. Mass spectrometric studies of 1-ethyl-3-methylimidazolium and 1-propyl-2,3-dimethylimidazolium bis(trifluoromethyl)-sulfonylimides.

    Science.gov (United States)

    Chilingarov, Norbert S; Medvedev, Artem A; Deyko, Grigoriy S; Kustov, Leonid M; Chernikova, Elena A; Glukhov, Lev M; Markov, Vitaliy Yu; Ioffe, Il'ya N; Senyavin, Vladimir M; Polyakova, Marina V; Sidorov, Lev N

    2015-07-15

    Ionic liquids ([Cat(+)][An(-)]) were believed to decompose before reaching vaporization temperatures, but recently some of them have been shown to vaporize congruently. Low-temperature vaporization of ionic substances is an intriguing phenomenon, so the vapor-phase composition and reactions of ionic liquids deserve more extensive study. Evaporation of two ionic liquids, [C2MIM(+)][Tf2 N(-)] and [C3MMIM(+)][Tf2N(-)], was studied by means of Knudsen effusion mass spectrometry. These liquids were also characterized using matrix-assisted laser desorption/ionization (MALDI) mass spectrometry, UV/Vis, IR, NMR spectroscopy, and elemental analysis. The vaporization enthalpies of (118 ± 3) and (124 ± 2) kJ·mol(-1) were determined for [C2MIM(+)][Tf2N(-)] and [C3MMIM(+)][Tf2N(-)], respectively. The corresponding equations for their saturated vapor pressures are: ln(p{[C2MIM(+)][Tf2N(-)]}/Pa) = -(14213 ± 325)/(T/K) + (26.57 ± 1.04), ln(p{[C2MMIM(+)][Tf2N(-)]}/Pa) = -(14868 ± 221)/(T/K) + (27.19 ± 0.60). The MALDI studies (positive and negative ion modes) enabled detection of monomeric [Cat(+)] and [An(-)] ions, the cluster ions {[Cat(+)]2 [An(-)]}(+) and {[Cat(+)][An(-)]2}(-), and some complex anions {2[An(-)] + Na(+)}(-), {2[An(-)] + K(+)}(-), {2[An(-)] + Cu(+)}(-) and {3[An(-)] + Ca(2+)}(-). Knudsen effusion mass spectrometry proved to be a valuable method to study the thermodynamics of ionic liquids. The saturated vapor pressure and vaporization enthalpy of [C3MMIM(+)][Tf2N(-)] were accurately determined for the first time. MALDI is also capable of providing indirect information on hydrogen bonding. Copyright © 2015 John Wiley & Sons, Ltd.

  15. Mass spectrometric study of thermodynamic properties of gaseous lead tellurates. Estimation of formation enthalpies of gaseous lead polonates

    Energy Technology Data Exchange (ETDEWEB)

    Shugurov, S.M., E-mail: s.shugurov@spbu.ru; Panin, A.I.; Lopatin, S.I.; Emelyanova, K.A.

    2016-10-15

    Gaseous reactions involving lead oxides, tellurium oxide and lead tellurates were studied by the Knudsen effusion mass spectrometry. Equilibrium constants and reaction enthalpies were evaluated. Structures, molecular parameters and thermodynamic functions of gaseous PbTeO{sub 3} and Pb{sub 2}TeO{sub 4} were calculated by quantum chemistry methods. The formation enthalpies Δ{sub f}H{sup 0} (298.15) = −294 ± 13 for gaseous PbTeO{sub 3} and Δ{sub f}H{sup 0} (298.15) = −499 ± 12 for gaseous Pb{sub 2}TeO{sub 4} were obtained. On the base of these results the formation enthalpies of gaseous PbPoO{sub 3} and Pb{sub 2}PoO{sub 4} were estimated as −249 ± 34 and −478 ± 38, respectively. - Highlights: • Gaseous lead tellurates PbTeO{sub 3}, Pb{sub 2}TeO{sub 4} were discovered. • Their thermodynamic properties were studied using both high temperature mass spectrometry and quantum chemistry computations. • The obtained data allows to predict the formation enthalpies of gaseous lead polonates PbPoO{sub 3}, Pb{sub 2}PoO{sub 4}.

  16. Model mass spectrometric study of competitive interactions of antimicrobial bisquaternary ammonium drugs and aspirin with membrane phospholipids

    Directory of Open Access Journals (Sweden)

    Vekey K.

    2013-03-01

    Full Text Available The aim of the study is to reveal molecular mechanisms of possible activity modulation of antimicrobial bis-quaternary ammonium compounds (BQAC and aspirin (ASP through noncovalent competitive complexation under their combined introduction into the model systems with membrane phospholipids. Methods. Binary and triple systems containing either decamethoxinum or ethonium, or thionium and aspirin, as well as dipalmitoyl-phosphatidylcholine (DPPC have been investigated by electrospray ionization mass spectrometry. Results. Basing on the analysis of associates recorded in the mass spectra, the types of nonocovalent complexes formed in the systems studied were determined and the supposed role of the complexation in the BQAC and ASP activity modulation was discussed. The formation of associates of BQAC dications with ASP anion is considered as one of the possible ways of deactivation of ionic forms of the medications. The formation of stable complexes of BQAC with DPPC and ASP with DPPC in binary systems as well as the complexes distribution in triple-components systems BQAC:ASP:DPPC point to the existence of competition between drugs of these two types for the binding to DPPC. Conclusions. The results obtained point to the competitive complexation in the model molecular systems containing the BQAC, aspirin and membrane phospholipids. The observed phenomenon testifies to the possibility of modulating the activity of bisquaternary antimicrobial agents and aspirin under their combined usage, due to the competition between the drugs for binding to the target membrane phospholipid molecules and also due to the formation of stable noncovalent complexes between BQAC and ASP.

  17. Study of matrix effects on the direct trace analysis of acidic pesticides in water using various liquid chromatographic modes coupled to tandem mass spectrometric detection.

    Science.gov (United States)

    Dijkman, E; Mooibroek, D; Hoogerbrugge, R; Hogendoorn, E; Sancho, J V; Pozo, O; Hernández, F

    2001-08-10

    This study investigated the effects of matrix interferences on the analytical performance of a triple quadrupole mass spectrometric (MS-MS) detector coupled to various reversed-phase liquid chromatographic (LC) modes for the on-line determination of various types of acidic herbicides in water using external calibration for quantification of the analytes tested at a level of 0.4 microg/l. The LC modes included (i) a single-column configuration (LC), (ii) precolumn switching (PC-LC) and (iii) coupled-column LC (LC-LC). As regards detection, electrospray (ESI) and atmospheric pressure chemical ionization (APCI) in both positive (PI) and negative (NI) ionization modes were examined. Salinity and dissolved organic carbon (DOC) were selected as interferences to study matrix effects in this type of analysis. Therefore, Milli-Q and tap water samples both fortified with 12 mg/l DOC and spiked with sulfometuron-methyl, bentazone, bromoxynil, 2-methyl-4-chlorophenoxyacetic acid, and 2-methyl-4-chlorophenoxypropionic acid at a level of about 0.4 microg/l were analyzed with the various LC-MS approaches. Direct sample injection was performed with volumes of 0.25 ml or 2.0 ml on a column of 2.1 mm I.D. or 4.6 mm I.D. for the ESI and APCI modes, respectively. The recovery data were used to compare and evaluate the analytical performance of the various LC approaches. As regards matrix effects, the salinity provided a dramatic decrease in response for early eluting analytes (k value of about 1) when using the LC mode. Both PC-LC and LC-LC efficiently eliminated this problem. The high DOC content hardly effected the responses of analytes in the ESI mode, while in most cases the responses increased when using APCI-MS-MS detection. Of all the tested configurations, LC-LC-ESI-MS-MS with the column combination Discovery C18/ABZ+ was the most favorable as regards elimination of matrix effects and provided reliable quantification of all compounds using external calibration at the tested

  18. Absorption spectrometric and thermodynamic study of charge transfer complexes of menadione (Vitamin K3) with a series of phenols.

    Science.gov (United States)

    Pal, Purnendu; Bhattacharya, Sumanta; Mukherjee, Asok K; Mukherjee, Dulal C

    2005-03-01

    The electron donor-acceptor (EDA) interactions between menadione (i.e., 2-methyl-1,4-naphthoquinone, which is also called 'Vitamin K3') and a series of phenols (viz., phenol, resorcinol and p-quinol) have been studied in CCl4 medium. In all the cases, charge transfer (CT) bands have been located. The CT transition energies (h nu(CT)) of the complexes are found to change systematically with change in the number and position of the -OH groups in the aromatic ring of the phenol moiety. From the trends in the h nu(CT) values, the Hückel parameters (h(O) and k(C-O)) for the -OH group have been obtained. The CT transition energies are well correlated with the ionisation potentials of the phenols. From an analysis of this variation the electron affinity of Vitamin K3 has been found to be 2.28 eV. The stoichiometry of the complexes in each case has been found to be 1(menadione):2 (phenol). Formation constants of the complexes have been determined at four different temperatures from which the enthalpies and entropies of formation of the complexes have been estimated.

  19. Absorption spectrometric and thermodynamic study of charge transfer complexes of menadione (Vitamin K 3) with a series of phenols

    Science.gov (United States)

    Pal, Purnendu; Bhattacharya, Sumanta; Mukherjee, Asok K.; Mukherjee, Dulal C.

    2005-03-01

    The electron donor-acceptor (EDA) interactions between menadione (i.e., 2-methyl-1,4-naphthoquinone, which is also called 'Vitamin K 3') and a series of phenols (viz., phenol, resorcinol and p-quinol) have been studied in CCl 4 medium. In all the cases, charge transfer (CT) bands have been located. The CT transition energies ( hνCT) of the complexes are found to change systematically with change in the number and position of the -OH groups in the aromatic ring of the phenol moiety. From the trends in the hνCT values, the Hückel parameters ( hÖ and kC-Ö) for the -OH group have been obtained. The CT transition energies are well correlated with the ionisation potentials of the phenols. From an analysis of this variation the electron affinity of Vitamin K 3 has been found to be 2.28 eV. The stoichiometry of the complexes in each case has been found to be 1(menadione):2 (phenol). Formation constants of the complexes have been determined at four different temperatures from which the enthalpies and entropies of formation of the complexes have been estimated.

  20. Preparation and spectrometric identification of amide derivatives with antimalaric

    International Nuclear Information System (INIS)

    Ferreira, E.J.

    1987-01-01

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

  1. Mass Spectrometric Analysis of Synthetic Organic Pigments.

    Science.gov (United States)

    Sugaya, Naeko; Takahashi, Mitsuko; Sakurai, Katsumi; Tanaka, Nobuko; Okubo, Ichiro; Kawakami, Tsuyoshi

    2018-04-18

    Though synthetic organic colorants are used in various applications nowadays, there is the concern that impurities by-produced during the manufacturing and degradation products in some of these colorants are persistent organic pollutants and carcinogens. Thus, it is important to identify the synthetic organic colorants in various products, such as commercial paints, ink, cosmetics, food, textile, and plastics. Dyes, which are soluble in water and other solvents, could be analyzed by chromatographic methods. In contrast, it is difficult to analyze synthetic organic pigments by these methods because of their insolubility. This review is an overview of mass spectrometric analysis of synthetic organic pigments by various ionization methods. We highlight a recent study of textile samples by atmospheric pressure solid analysis probe MS. Furthermore, the mass spectral features of synthetic organic pigments and their separation from other components such as paint media and plasticizers are discussed.

  2. Gas chromatography-mass spectrometric determination of traces of ether-type icing inhibitors in free-floating fuels

    Energy Technology Data Exchange (ETDEWEB)

    Shin, H.S. [Dept. of Environmental Education, Kongju National Univ., Kongju (Korea); Abuse Drug Research Center, Kongju National Univ., Kongju (Korea); Ahn, H.S. [Dept. of Environmental Science, Kongju National Univ., Kongju (Korea)

    2004-08-01

    A gas chromatographic-mass spectrometric (GC-MS) assay method has been developed for simultaneous determination of ethylene glycol monomethyl ether (EGME) and diethylene glycol monomethly ether (DEGME) in spilled aviation fuels. Ethylene glycol monobutyl ether (EGBE) and ethylene glycol monoethyl ether (EGEE) were used as internal standard and surrogate, respectively. Sample preparation consisted of back-extraction with 7 mL dichloromethane after extraction of 50 mL of fuel with 2 mL of water. The extract was concentrated to dryness, dissolved in 100 {mu}L methanol, and analyzed by GC-MS with selected-ion monitoring (SIM). The peaks had good chromatographic properties on a semi-polar column. EGME and DEGME were extracted from fuel with high recovery of 75 and 85%, with small variations, respectively. Method detection limits were 1.3 and 1.0 ng mL{sup -1} for EGME and DEGME, respectively, in spilled fuel. DEGME was detected at concentrations of 22.6 and 19.7 ng mL{sup -1} in two samples from among five free-floating samples collected in a tunnel of a subway station located in the vicinity of an army base in Korea. The method might be useful for differentiation between the fuel-types kerosene and JP-8, which might originate from a storage tank. (orig.)

  3. Development of high-spatial and high-mass resolution mass spectrometric imaging (MSI) and its application to the study of small metabolites and endogenous molecules of plants

    Energy Technology Data Exchange (ETDEWEB)

    Jun, Ji Hyun [Iowa State Univ., Ames, IA (United States)

    2012-01-01

    High-spatial and high-mass resolution laser desorption ionization (LDI) mass spectrometric (MS) imaging technology was developed for the attainment of MS images of higher quality containing more information on the relevant cellular and molecular biology in unprecedented depth. The distribution of plant metabolites is asymmetric throughout the cells and tissues, and therefore the increase in the spatial resolution was pursued to reveal the localization of plant metabolites at the cellular level by MS imaging. For achieving high-spatial resolution, the laser beam size was reduced by utilizing an optical fiber with small core diameter (25 μm) in a vacuum matrix-assisted laser desorption ionization-linear ion trap (vMALDI-LTQ) mass spectrometer. Matrix application was greatly improved using oscillating capillary nebulizer. As a result, single cell level spatial resolution of ~ 12 μm was achieved. MS imaging at this high spatial resolution was directly applied to a whole Arabidopsis flower and the substructures of an anther and single pollen grains at the stigma and anther were successfully visualized. MS imaging of high spatial resolution was also demonstrated to the secondary roots of Arabidopsis thaliana and a high degree of localization of detected metabolites was successfully unveiled. This was the first MS imaging on the root for molecular species. MS imaging with high mass resolution was also achieved by utilizing the LTQ-Orbitrap mass spectrometer for the direct identification of the surface metabolites on the Arabidopsis stem and root and differentiation of isobaric ions having the same nominal mass with no need of tandem mass spectrometry (MS/MS). MS imaging at high-spatial and high-mass resolution was also applied to cer1 mutant of the model system Arabidopsis thaliana to demonstrate its usefulness in biological studies and reveal associated metabolite changes in terms of spatial distribution and/or abundances compared to those of wild-type. The spatial

  4. Mass spectrometric detection of radiocarbon for dating applications

    OpenAIRE

    Synal Hans-Arno

    2013-01-01

    Radiocarbon is still the most important nuclide measured by accelerator mass spectrometry (AMS). The related capabilities for dating and tracer studies are eminent not only in archaeology but also drive important applications in the earth and environmental sciences as well as in biomedical research. So far standard mass spectrometric systems have not been capable of radiocarbon dating because of interfering molecular isobars which however can be completely eliminated in charge changing proces...

  5. Rapid, Sensitive and Validated Ultra-Performance Liquid Chromatography/Mass Spectrometric Method for the Determination of Fenofibric Acid and its Application to Human Pharmacokinetic Study

    Directory of Open Access Journals (Sweden)

    Sunil K. Dubey

    2010-01-01

    Full Text Available The first, rapid and sensitive ultra performance liquid chromatography mass spectrometric method for the determination of fenofibric acid, the active metabolite of fenofibrate, a lipid regulating agent, in human EDTA plasma has been developed and validated using fenofibric d6 acid as internal standard and Waters LC-MS/MS. Negative ions of fenofibric acid and fenofibric d6 acid were detected in multiple reaction-monitoring (MRM mode. The method was validated over a concentration range of 0.176 μg/mL to 19.837 μg/mL (r ≥ 0.99. It took only 1.5 minute to analyse a sample. Intra- and inter-run precision of fenofibric acid assay at four concentrations ranged from 0.5% to 4.3% with accuracy varied from 93.1 to 108.1% indicating good precision and accuracy. Analytical recoveries of fenofibric acid and internal standard in plasma were less than 90%. This method was successfully applied for evaluation of pharmacokinetics of fenofibric acid after a single oral dose of 145 mg fenofibrate to 10 Indian healthy volunteers

  6. Light-induced alterations of pineapple (Ananas comosus [L.] Merr.) juice volatiles during accelerated ageing and mass spectrometric studies into their precursors.

    Science.gov (United States)

    Steingass, Christof Björn; Glock, Mona Pia; Lieb, Veronika Maria; Carle, Reinhold

    2017-10-01

    Alterations of volatiles during accelerated light-induced ageing of pineapple juice were assessed by HS-SPME-GC-MS in a non-targeted profiling analysis over a 16-week period. Multivariate statistics permitted to reveal substantial chemical markers generally describing the effect of light storage. Volatiles generated comprised phenylpropenes, carbonyls, 2-methylthiophene, toluene, and furfural, while concentrations of methyl and ethyl esters, terpenes, and furanones decreased. In addition, the qualitative composition of phenolic compounds and glycoside-bound volatiles in selected samples was characterized by HPLC-DAD-ESI-MS n as well as HR-ESI-MS. The fresh juice contained unique pineapple metabolites such as S-p-coumaryl, S-coniferyl, S-sinapylglutathione, and structurally related derivatives. Among others, the presence of p-coumaroyl, feruloyl, and caffeoylisocitrate as well as three 4-hydroxy-2,5-dimethyl-3(2H)-furanone glycosides in pineapples could be substantiated by the HR-ESI-MS experiment. Mass spectrometric assignments of selected metabolites are presented, and putative linkages between volatiles and their precursors are established. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Degradation of Adenine on the Martian Surface in the Presence of Perchlorates and Ionizing Radiation: A Reflectron Time-of-flight Mass Spectrometric Study

    Energy Technology Data Exchange (ETDEWEB)

    Góbi, Sándor; Bergantini, Alexandre; Kaiser, Ralf I., E-mail: ralfk@hawaii.edu [Department of Chemistry, University of Hawaii at Mānoa, Honolulu, HI 96822 (United States)

    2017-04-01

    The aim of the present work is to unravel the radiolytic decomposition of adenine (C{sub 5}H{sub 5}N{sub 5}) under conditions relevant to the Martian surface. Being the fundamental building block of (deoxy)ribonucleic acids, the possibility of survival of this biomolecule on the Martian surface is of primary importance to the astrobiology community. Here, neat adenine and adenine–magnesium perchlorate mixtures were prepared and irradiated with energetic electrons that simulate the secondary electrons originating from the interaction of the galactic cosmic rays with the Martian surface. Perchlorates were added to the samples since they are abundant—and therefore relevant oxidizers on the surface of Mars—and they have been previously shown to facilitate the radiolysis of organics such as glycine. The degradation of the samples were monitored in situ via Fourier transformation infrared spectroscopy and the electron ionization quadruple mass spectrometric method; temperature-programmed desorption profiles were then collected by means of the state-of-the-art single photon photoionization reflectron time-of-flight mass spectrometry (PI-ReTOF-MS), allowing for the detection of the species subliming from the sample. The results showed that perchlorates do increase the destruction rate of adenine by opening alternative reaction channels, including the concurrent radiolysis/oxidation of the sample. This new pathway provides a plethora of different radiolysis products that were identified for the first time. These are carbon dioxide (CO{sub 2}), isocyanic acid (HNCO), isocyanate (OCN{sup −}), carbon monoxide (CO), and nitrogen monoxide (NO); an oxidation product containing carbonyl groups (R{sub 1}R{sub 2}–C=O) with a constrained five-membered cyclic structure could also be observed. Cyanamide (H{sub 2}N–C≡N) was detected in both irradiated samples as well.

  8. Degradation of Adenine on the Martian Surface in the Presence of Perchlorates and Ionizing Radiation: A Reflectron Time-of-flight Mass Spectrometric Study

    International Nuclear Information System (INIS)

    Góbi, Sándor; Bergantini, Alexandre; Kaiser, Ralf I.

    2017-01-01

    The aim of the present work is to unravel the radiolytic decomposition of adenine (C 5 H 5 N 5 ) under conditions relevant to the Martian surface. Being the fundamental building block of (deoxy)ribonucleic acids, the possibility of survival of this biomolecule on the Martian surface is of primary importance to the astrobiology community. Here, neat adenine and adenine–magnesium perchlorate mixtures were prepared and irradiated with energetic electrons that simulate the secondary electrons originating from the interaction of the galactic cosmic rays with the Martian surface. Perchlorates were added to the samples since they are abundant—and therefore relevant oxidizers on the surface of Mars—and they have been previously shown to facilitate the radiolysis of organics such as glycine. The degradation of the samples were monitored in situ via Fourier transformation infrared spectroscopy and the electron ionization quadruple mass spectrometric method; temperature-programmed desorption profiles were then collected by means of the state-of-the-art single photon photoionization reflectron time-of-flight mass spectrometry (PI-ReTOF-MS), allowing for the detection of the species subliming from the sample. The results showed that perchlorates do increase the destruction rate of adenine by opening alternative reaction channels, including the concurrent radiolysis/oxidation of the sample. This new pathway provides a plethora of different radiolysis products that were identified for the first time. These are carbon dioxide (CO 2 ), isocyanic acid (HNCO), isocyanate (OCN − ), carbon monoxide (CO), and nitrogen monoxide (NO); an oxidation product containing carbonyl groups (R 1 R 2 –C=O) with a constrained five-membered cyclic structure could also be observed. Cyanamide (H 2 N–C≡N) was detected in both irradiated samples as well.

  9. Acetylation and glycation of fibrinogen in vitro occur at specific lysine residues in a concentration dependent manner: A mass spectrometric and isotope labeling study

    International Nuclear Information System (INIS)

    Svensson, Jan; Bergman, Ann-Charlotte; Adamson, Ulf; Blombäck, Margareta; Wallén, Håkan; Jörneskog, Gun

    2012-01-01

    Highlights: ► Fibrinogen was incubated in vitro with glucose or aspirin. ► Acetylations and glycations were found at twelve lysine sites by mass spectrometry. ► The labeling by aspirin and glucose occurred dose-dependently. ► No competition between glucose and aspirin for binding to fibrinogen was found. -- Abstract: Aspirin may exert part of its antithrombotic effects through platelet-independent mechanisms. Diabetes is a condition in which the beneficial effects of aspirin are less prominent or absent – a phenomenon called “aspirin resistance”. We investigated whether acetylation and glycation occur at specific sites in fibrinogen and if competition between glucose and aspirin in binding to fibrinogen occurs. Our hypothesis was that such competition might be one explanation to “aspirin resistance” in diabetes. After incubation of fibrinogen in vitro with aspirin (0.8 mM, 24 h) or glucose (100 mM, 5–10 days), we found 12 modified sites with mass spectrometric techniques. Acetylations in the α-chain: αK191, αK208, αK224, αK429, αK457, αK539, αK562, in the β-chain: βK233, and in the γ-chain: γK170 and γK273. Glycations were found at βK133 and γK75, alternatively γK85. Notably, the lysine 539 is a site involved in FXIII-mediated cross-linking of fibrin. With isotope labeling in vitro, using [ 14 C-acetyl]salicylic acid and [ 14 C]glucose, a labeling of 0.013–0.084 and 0.12–0.5 mol of acetylated and glycated adduct/mol fibrinogen, respectively, was found for clinically (12.9–100 μM aspirin) and physiologically (2–8 mM glucose) relevant plasma concentrations. No competition between acetylation and glycation could be demonstrated. Thus, fibrinogen is acetylated at several lysine residues, some of which are involved in the cross-linking of fibrinogen. This may mechanistically explain why aspirin facilitates fibrin degradation. We find no support for the idea that glycation of fibrin(ogen) interferes with acetylation of

  10. Acetylation and glycation of fibrinogen in vitro occur at specific lysine residues in a concentration dependent manner: A mass spectrometric and isotope labeling study

    Energy Technology Data Exchange (ETDEWEB)

    Svensson, Jan, E-mail: jan.svensson@ki.se [Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital (Solna), SE-171 76 Stockholm (Sweden); Karolinska Institutet, Department of Clinical Sciences, Danderyd Hospital, SE-182 88 Stockholm (Sweden); Bergman, Ann-Charlotte [Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital (Solna), SE-171 76 Stockholm (Sweden); Adamson, Ulf [Karolinska Institutet, Department of Clinical Sciences, Danderyd Hospital, SE-182 88 Stockholm (Sweden); Blombaeck, Margareta [Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital (Solna), SE-171 76 Stockholm (Sweden); Wallen, Hakan; Joerneskog, Gun [Karolinska Institutet, Department of Clinical Sciences, Danderyd Hospital, SE-182 88 Stockholm (Sweden)

    2012-05-04

    Highlights: Black-Right-Pointing-Pointer Fibrinogen was incubated in vitro with glucose or aspirin. Black-Right-Pointing-Pointer Acetylations and glycations were found at twelve lysine sites by mass spectrometry. Black-Right-Pointing-Pointer The labeling by aspirin and glucose occurred dose-dependently. Black-Right-Pointing-Pointer No competition between glucose and aspirin for binding to fibrinogen was found. -- Abstract: Aspirin may exert part of its antithrombotic effects through platelet-independent mechanisms. Diabetes is a condition in which the beneficial effects of aspirin are less prominent or absent - a phenomenon called 'aspirin resistance'. We investigated whether acetylation and glycation occur at specific sites in fibrinogen and if competition between glucose and aspirin in binding to fibrinogen occurs. Our hypothesis was that such competition might be one explanation to 'aspirin resistance' in diabetes. After incubation of fibrinogen in vitro with aspirin (0.8 mM, 24 h) or glucose (100 mM, 5-10 days), we found 12 modified sites with mass spectrometric techniques. Acetylations in the {alpha}-chain: {alpha}K191, {alpha}K208, {alpha}K224, {alpha}K429, {alpha}K457, {alpha}K539, {alpha}K562, in the {beta}-chain: {beta}K233, and in the {gamma}-chain: {gamma}K170 and {gamma}K273. Glycations were found at {beta}K133 and {gamma}K75, alternatively {gamma}K85. Notably, the lysine 539 is a site involved in FXIII-mediated cross-linking of fibrin. With isotope labeling in vitro, using [{sup 14}C-acetyl]salicylic acid and [{sup 14}C]glucose, a labeling of 0.013-0.084 and 0.12-0.5 mol of acetylated and glycated adduct/mol fibrinogen, respectively, was found for clinically (12.9-100 {mu}M aspirin) and physiologically (2-8 mM glucose) relevant plasma concentrations. No competition between acetylation and glycation could be demonstrated. Thus, fibrinogen is acetylated at several lysine residues, some of which are involved in the cross-linking of

  11. Selection and optimization of spectrometric amplifiers for gamma spectrometry: part II - linearity, live time correction factors and software

    International Nuclear Information System (INIS)

    Moraes, Marco Antonio Proenca Vieira de; Pugliesi, Reinaldo

    1996-01-01

    The objective of the present work was to establish simple criteria to choose the best combination of electronic modules to achieve an adequate high resolution gamma spectrometer. Linearity, live time correction factors and softwares of a gamma spectrometric system composed by a Hp Ge detector have been studied by using several kinds of spectrometric amplifiers: Canberra 2021, Canberra 2025, Ortec 673 and Tennelec 244 and the MCA cards Ortec and Nucleus. The results showed low values of integral non-linearity for all spectrometric amplifiers connected to the Ortec and Nucleus boards. The MCA card should be able to correct amplifier dead time for 17 kcps count rates. (author)

  12. Mass spectrometric researches in isotope cosmochemistry

    International Nuclear Information System (INIS)

    Gopalan, K.

    1979-01-01

    Recent advances in the understanding of solar system processes, past and present, based on mass spectrometric researches on meteorites and moon samples are reviewed. The topics include the following : (1) Duration of nebular condensation, (2) Terminal stages of nucleosynthesis, (3) Planetary formation and evolution, (4) Heterogeneities in the solar nebula and (5) Solar wind composition. (auth.)

  13. A novel reversed-phase HPLC method for the determination of urinary creatinine by pre-column derivatization with ethyl chloroformate: comparative studies with the standard Jaffé and isotope-dilution mass spectrometric assays.

    Science.gov (United States)

    Leung, Elvis M K; Chan, Wan

    2014-02-01

    Creatinine is an important biomarker for renal function diagnosis and normalizing variations in urinary drug/metabolites concentration. Quantification of creatinine in biological fluids such as urine and plasma is important for clinical diagnosis as well as in biomonitoring programs and urinary metabolomics/metabonomics research. Current methods for creatinine determination either are nonselective or involve the use of expensive mass spectrometers. In this paper, a novel reversed-phase high-performance liquid chromatographic (HPLC) method for the determination of creatinine of high hydrophilicity by pre-column derivatization with ethyl chloroformate is presented. N-Ethyloxycarbonylation of creatinine significantly enhanced the hydrophobicity of creatinine, facilitating its chromatographic retention as well as quantification by HPLC. Factors governing the derivatization reaction were studied and optimized. The developed method was validated and applied for the determination of creatinine in rat urine samples. Comparative studies with isotope-dilution mass spectrometric method revealed that the two methods do not yield systematic differences in creatinine concentrations, indicating the HPLC method is suitable for the determination of creatinine in urine samples.

  14. Chemical studies on oils derived from aspen poplar wood, cellulose, and an isolated aspen poplar lignin

    Energy Technology Data Exchange (ETDEWEB)

    Eager, R L; Pepper, J M; Roy, J C; Mathews, J F

    1983-01-01

    An initial study has been made of the chemical nature of the oil phase resulting from the conversion of aspen poplar wood, cellulose, and an isolated lignin from the aspen poplar as a result of their interactions with water and carbon monoxide in the presence of sodium carbonate at 360 degrees C. Gas chromatographic analysis of the sodium hydroxide soluble fractions from each substrate revealed similar spectra of alkyl-substituted phenols. The relative abundance of identified low molecular weight phenolic compounds decreased from lignin to wood to cellulose. This was in agreement with the known phenolic nature of lignin. As well, it confirmed the synthesis during reaction of such compounds from a carbohydrate substrate. Gas chromatographic analysis of the whole oils also revealed the presence in each case of several alkyl-substituted cyclopentanones whose relative abundance decreased from cellulose to wood to lignin. Silica gel column separation of the oils, after a charcoal treatment, followed by capillary gas chromatographic - mass spectrometric analyses of the resulting fraction indicated the presence of other higher molecular weight phenols, napthols, cycloalkanols, and polycyclic and long chain alkanes and alkenes.

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

    Science.gov (United States)

    Gemperline, Erin; Chen, Bingming; Li, Lingjun

    2014-01-01

    Mass spectrometric imaging (MSI) is a powerful tool that grants the ability to investigate a broad mass range of molecules, from small molecules to large proteins, by creating detailed distribution maps of selected compounds. To date, MSI has demonstrated its versatility in the study of neurotransmitters and neuropeptides of different classes toward investigation of neurobiological functions and diseases. These studies have provided significant insight in neurobiology over the years and current technical advances are facilitating further improvements in this field. neurotransmitters, focusing specifically on the challenges and recent Herein, we advances of MSI of neurotransmitters. PMID:24568355

  16. Thermogravimetric-quadrupole mass-spectrometric analysis of geochemical samples.

    Science.gov (United States)

    Gibson, E. K., Jr.; Johnson, S. M.

    1972-01-01

    Thermogravimetric-quadrupole mass-spectrometric-analysis techniques can be used to study a wide variety of problems involving decomposition processes and identification of released volatile components. A recording vacuum thermoanalyzer has been coupled with a quadrupole mass spectrometer. The rapid scan capabilities of the quadrupole mass spectrometer are used to identify the gaseous components released. The capability of the thermogravimetric-quadrupole mass spectrometer to provide analytical data for identification of the released volatile components, for determination of their sequence of release and for correlation of thermal-decomposition studies is illustrated by an analysis of the Orgueil carbonaceous chondrite.

  17. Development and validation of a sensitive liquid chromatographic-tandem mass spectrometric method for the simultaneous analysis of granisetron and 7-hydroxy granisetron in human plasma and urine samples: application in a clinical pharmacokinetic study in pregnant subject.

    Science.gov (United States)

    Zhao, Yang; Chen, Hui-Jun; Caritis, Steve; Venkataramanan, Raman

    2016-02-01

    A liquid chromatography-tandem mass spectrometric method for the quantification of granisetron and its major metabolite, 7-hydroxy granisetron in human plasma and urine samples was developed and validated. Respective stable isotopically labeled granisetron and 7-hydroxy granisetron were used as internal standards (IS). Chromatography was performed using an Xselect HSS T3 analytical column with a mobile phase of 20% acetonitrile in water (containing 0.2 mM ammonium formate and 0.14% formic acid, pH 4) delivered in an isocratic mode. Tandem mass spectrometry operating in positive electrospray ionization mode with multiple reaction monitoring was used for quantification. The standard curves were linear in the concentration ranges of 0.5-100 ng/mL for granisetron and 0.1-100 ng/mL for 7-hydroxy granisetron in human plasma samples, and 2-2000 ng/mL for granisetron and 2-1000 ng/mL for 7-hydroxy granisetron in human urine samples, respectively. The accuracies were >85% and the precision as determined by the coefficient of variations was granisetron or 7-hydroxy granisetron in either plasma or urine samples. Granisetron was stable under various storage and experimental conditions. This validated method was successfully applied to a pharmacokinetic study after intravenous administration of 1 mg granisetron to a pregnant subject. Copyright © 2015 John Wiley & Sons, Ltd.

  18. Development of gallium arsenide gamma spectrometric detector

    International Nuclear Information System (INIS)

    Kobayashi, T.; Kuru, I.

    1975-03-01

    GaAs semiconductor material has been considered to be a suitable material for gamma-ray spectrometer operating at room temperature since it has a wid-band gap, larger than that of silicon and germanium. The basic objective of this work is to develop a GaAs gamma-ray spectrometric detector which could be used for gamma spectrometric measurement of uranium and plutonium in nuclear fuel safeguards. Liquid phase epitaxial techniques using iron (Fe) as dopant have been developed in making high purity GaAs crystals suitable for gamma-ray spectrometer operating at room temperature. Concentration of Fe in the epitaxial crystal was controlled by initial growth temperature. The best quality epitaxial crystal was obtained under the following conditions: starting temperature is about 800degC, the proportion of Fe to Ga solvent is 1 to 300. Carrier concentration of epitaxial crystals grown distributed in the ranges of 10 12 cm -3 to 10 14 cm -3 at room temperature. The thickness of the crystals ranged from 38 μm to 120 μm. Au-GaAs surface barrier detector was made of epitaxial crystal. Some of the detector were encapsulated in a can with a 50 μm Be window by welding a can to the detector holder. The detector with high energy resolution and good charge collecting characteristics was selected by alpha spectrometry at room temperature. Energy resolution of the detector for gamma-rays up to about 200 keV was very good at room temperature operation. The best energy resolutions taken with a GaAs detector were 3 keV (fwhm) and 3.8 keV for 241 Am 59.6 keV and 57 Co 122 keV, respectively, at room temperature. In order to study the applicability of the detector for nuclear safeguards, the measurements of 235 U gamma-ray spectrum have been carried out at room temperature. It was clarified that the gamma-ray spectrum of enriched U sample could be measured in high resolution with GaAs detector at room temperature, and that the content of 235 U in enriched U sources could be determined by

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

    Energy Technology Data Exchange (ETDEWEB)

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

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

  20. Mass spectrometric investigation of fluorated europium β-diketonates

    International Nuclear Information System (INIS)

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

    1983-01-01

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

  1. Processing of gamma-ray spectrometric logs

    International Nuclear Information System (INIS)

    Umiastowski, K.; Dumesnil, P.

    1984-10-01

    CEA (Commissariat a l'Energie Atomique) has developped a gamma-ray spectrometric tool, containing an analog-to-digital converter. This new tool permits to perform very precise uranium logs (natural gamma-ray spectrometry), neutron activation logs and litho-density logs (gamma-gamma spectrometric logs). Specific processing methods were developped to treate the particular problems of down-hole gamma-ray spectrometry. Extraction of the characteristic gamma-ray peak, even if they are superposed on the background radiation of very high intensity, is possible. This processing methode enables also to obtain geological informations contained in the continuous background of the spectrum. Computer programs are written in high level language for SIRIUS (VICTOR) and APOLLO computers. Exemples of uranium and neutron activation logs treatment are presented [fr

  2. Electronic equipment for spectrometric data processing

    International Nuclear Information System (INIS)

    Antonov, L.J.; Trenev, A.M.; Todorova, E.I.; Dimitrov, V.D.

    1978-01-01

    Electronic equipment carrying out logical operations and a full set of the arithmetic operations was developed for spectrometric data processing. The flowsheet of the computing part of the device, made on the basis of a specialized integral circuit, is given. The device includes input registers, multiplexor, matrix commutator, arithmetic unit and indication unit. The equipment is rated to carry out calculations according to comparatively complex formulae in several seconds

  3. High-temperature mass spectrometric study of the vaporization processes and thermodynamic properties of melts in the PbO-B2O3-SiO2 system.

    Science.gov (United States)

    Stolyarova, V L; Lopatin, S I; Shilov, A L; Shugurov, S M

    2013-07-15

    The unique properties of the PbO-B2O3-SiO2 system, especially its extensive range of glass-forming compositions, make it valuable for various practical applications. The thermodynamic properties and vaporization of PbO-B2O3-SiO2 melts are not well established so far and the data obtained on these will be useful for optimization of technology and thermodynamic modeling of glasses. High-temperature Knudsen effusion mass spectrometry was used to study vaporization processes and to determine the partial pressures of components of the PbO-B2O3-SiO2 melts. Measurements were performed with a MS-1301 mass spectrometer. Vaporization was carried out using two quartz effusion cells containing the sample under study and pure PbO (reference substance). Ions were produced by electron ionization at an energy of 25 eV. To facilitate interpretation of the mass spectra, the appearance energies of ions were also measured. Pb, PbO and O2 were found to be the main vapor species over the samples studied at 1100 K. The PbO activities as a function of the composition of the system were derived from the measured PbO partial pressures. The B2O3 and SiO2 activities, the Gibbs energy of formation, the excess Gibbs energy of formation and mass losses in the samples studied were calculated. Partial pressures of the vapor species over PbO-B2O3-SiO2 melts were measured at 1100 K in the wide range of compositions using the Knudsen mass spectrometric method. The data enabled the PbO, B2O3, and SiO2 activities in these melts to be derived and provided evidence of their negative deviations from ideal behavior. Copyright © 2013 John Wiley & Sons, Ltd.

  4. Spectrometric properties and radiation damage of BGO crystals

    Science.gov (United States)

    Kim, Gen C.; Gasanov, Eldar M.

    1997-07-01

    Spectrometric properties, such as light output, energy resolution BGO crystals before and after (superscript 60)Co gamma-ray (dose 10(superscript 4) - 10(superscript 6) R) and neutron irradiation (fluence 10(superscript 14) cm(superscript -2)) are investigated. Condition for degradation of spectrometric properties and their recovering after irradiation are studied. The energy spectrum of the photons emitted from BGO crystals irradiated with neutron fluence contains the long living background peak which is caused by self-irradiation with radioactive isotopes produced in the crystals. The defect production was studied in crystals under the high dose gamma-irradiation with (superscript 60)Co isotope. It was found that after doses above 10(superscript 8) R the color center at 365 nm and doses higher than 10(superscript 9) R a wide absorption band in the region of 300 - 350 nm occur. Comparison of these results with those of reactor irradiation has shown that under the high dose gamma-irradiation the structure defect production takes place.

  5. Commercial Applications of X Ray Spectrometric Techniques

    International Nuclear Information System (INIS)

    Wegrzynek, D.

    2013-01-01

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

  6. Commercial Applications of X Ray Spectrometric Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Wegrzynek, D., E-mail: D.Wedgrznek@iaea.org [International Atomic Energy Agency, The IAEA Laboratories, Seibersdorf, Vienna (Austria)

    2013-07-15

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

  7. Mass spectrometric detection of radiocarbon for dating applications

    Energy Technology Data Exchange (ETDEWEB)

    Synal, H.-A., E-mail: synal@phys.ethz.ch [ETH Zurich, Laboratory of Ion Beam Physics, Building HPK, 8093 Zurich (Switzerland); Schulze-Koenig, T.; Seiler, M.; Suter, M.; Wacker, L. [ETH Zurich, Laboratory of Ion Beam Physics, Building HPK, 8093 Zurich (Switzerland)

    2013-01-15

    Radiocarbon is still the most important nuclide measured by accelerator mass spectrometry (AMS). The related capabilities for dating and tracer studies are eminent not only in archaeology but also drive important applications in the earth and environmental sciences as well as in biomedical research. So far, standard mass spectrometric systems have not been capable of radiocarbon dating because of interfering molecular isobars which, however, can be completely eliminated in charge changing processes at high ion beam energies (MeV) [1,2]. Here, we present a novel type mass spectrometry system for radiocarbon analyses. Radiocarbon dating was performed using 45 keV {sup 14}C ions from the ion source and a molecule dissociation unit kept at ground potential. This proof-of-principle experiment demonstrates for the first time the feasibility of mass spectrometric radiocarbon dating without an accelerator. The results obtained will be the basis of an optimized design for a radiocarbon dating instrument comparable in size, complexity and cost to standard mass spectrometers.

  8. Mass spectrometric detection of radiocarbon for dating applications

    International Nuclear Information System (INIS)

    Synal, H.-A.; Schulze-König, T.; Seiler, M.; Suter, M.; Wacker, L.

    2013-01-01

    Radiocarbon is still the most important nuclide measured by accelerator mass spectrometry (AMS). The related capabilities for dating and tracer studies are eminent not only in archaeology but also drive important applications in the earth and environmental sciences as well as in biomedical research. So far, standard mass spectrometric systems have not been capable of radiocarbon dating because of interfering molecular isobars which, however, can be completely eliminated in charge changing processes at high ion beam energies (MeV) [1,2]. Here, we present a novel type mass spectrometry system for radiocarbon analyses. Radiocarbon dating was performed using 45 keV 14 C ions from the ion source and a molecule dissociation unit kept at ground potential. This proof-of-principle experiment demonstrates for the first time the feasibility of mass spectrometric radiocarbon dating without an accelerator. The results obtained will be the basis of an optimized design for a radiocarbon dating instrument comparable in size, complexity and cost to standard mass spectrometers.

  9. Mass spectrometric detection of radiocarbon for dating applications

    Science.gov (United States)

    Synal, H.-A.; Schulze-König, T.; Seiler, M.; Suter, M.; Wacker, L.

    2013-01-01

    Radiocarbon is still the most important nuclide measured by accelerator mass spectrometry (AMS). The related capabilities for dating and tracer studies are eminent not only in archaeology but also drive important applications in the earth and environmental sciences as well as in biomedical research. So far, standard mass spectrometric systems have not been capable of radiocarbon dating because of interfering molecular isobars which, however, can be completely eliminated in charge changing processes at high ion beam energies (MeV) [1,2]. Here, we present a novel type mass spectrometry system for radiocarbon analyses. Radiocarbon dating was performed using 45 keV 14C ions from the ion source and a molecule dissociation unit kept at ground potential. This proof-of-principle experiment demonstrates for the first time the feasibility of mass spectrometric radiocarbon dating without an accelerator. The results obtained will be the basis of an optimized design for a radiocarbon dating instrument comparable in size, complexity and cost to standard mass spectrometers.

  10. Spectrometric control of radionuclides production parameters

    International Nuclear Information System (INIS)

    Zhuk, I.; Potarenko, A.; Yarochevich, O.; Hluboky, N.; Kerko, P.; Bogdanov, V.; Dyatel, N.

    2006-01-01

    Full text: A radioactive preparations and sources are widely used all over the world for scientific, industrial and medical purposes. These preparations in Belarus are planned to produce by the Joint Belarussian-Russian Closed Joint Stock Company 'Isotope technologies' (CJSC IT). The company was created in 1998 by two leading scientific centers-SSI 'Joint Institute of Power and Nuclear Research-Sosny' the National Academy of Sciences of Belarus and the State Center of Science of the Russian Federation 'Scientific research institute of nuclear reactors'. One of the mainstream directions in CJSC IT activities is production of radioactive preparations for the industrial and scientific application (such as 133 Ba, 109 Cd, 63 Ni, 60 Co) and for the medical purposes (such as 19 '2Ir, 60 Co). All radioactive preparations have a good export potential and adequate to modern technical and consumer requirements. X-γ spectrometric analysis of considered radioactive sources is one of the basic methods for quality control of radioactive sources. At present, we are developing x-γ spectrometric support of purification process from contaminating radionuclides of 109 Cd -γ preparation and 63 Ni - β preparation. Work on x-γ spectrometric quality control of 133 Ba preparation is carried out. The description of the used equipment is given. Techniques of contaminating radionuclides determination (contents ∼10 - '6 from activity of the basic radionuclide) are presented. Problems of the choice of geometry of measurements of sources with activity about 10 7 -10 9 Bq and possible sources of errors are discussed. (author)

  11. Structure elucidation of metabolite x17299 by interpretation of mass spectrometric data.

    Science.gov (United States)

    Zhang, Qibo; Ford, Lisa A; Evans, Anne M; Toal, Douglas R

    2017-01-01

    A major bottleneck in metabolomic studies is metabolite identification from accurate mass spectrometric data. Metabolite x17299 was identified in plasma as an unknown in a metabolomic study using a compound-centric approach where the associated ion features of the compound were used to determine the true molecular mass. The aim of this work is to elucidate the chemical structure of x17299, a new compound by de novo interpretation of mass spectrometric data. An Orbitrap Elite mass spectrometer was used for acquisition of mass spectra up to MS 4 at high resolution. Synthetic standards of N,N,N -trimethyl-l-alanyl-l-proline betaine (l,l-TMAP), a diastereomer, and an enantiomer were chemically prepared. The planar structure of x17299 was successfully proposed by de novo mechanistic interpretation of mass spectrometric data without any laborious purification and nuclear magnetic resonance spectroscopic analysis. The proposed structure was verified by deuterium exchanged mass spectrometric analysis and confirmed by comparison to a synthetic standard. Relative configuration of x17299 was determined by direct chromatographic comparison to a pair of synthetic diastereomers. Absolute configuration was assigned after derivatization of x17299 with a chiral auxiliary group followed by its chromatographic comparison to a pair of synthetic standards. The chemical structure of metabolite x17299 was determined to be l,l-TMAP.

  12. A measuring generator for testing spectrometric channels

    International Nuclear Information System (INIS)

    Dinh Sy Hien; Kalinkin, A.I.

    1984-01-01

    A measuring generator for testing and tuning an amplitude spectrometric channel is described. The device consists of a pseudo random pulse generator, constructed on shifters, a sawtooth wave generator and a shaper of stable amplitude pulses with exponential decay times. The device is made as CAMAC unit width modules and has the following specifications: average pulse repetition rate of pseudo random pulses is 3.1; 25; 50; 100; 200 kHz; peak amplitude of 2 Hz pulse repetition of saw tooth pulses is 6 V; peak amplitude of exponential shape pulses is 5 V. The block-diagram and basic circuits of the device are given

  13. Dosimetric studies, spectrometric, radiographic, metallographic of a new argentinean seed of {sup 125} I used in brachytherapy; Estudios dosimetricos, espectrometricos, radiograficos, metalograficos de una nueva semilla argentina de {sup 125}I empleada en braquiterapia

    Energy Technology Data Exchange (ETDEWEB)

    Pirchio, R.; Saravi, M.; Banchik, D.; Munoz, C. [CNEA, Pbro. J. Gonzalez y Aragon No. 15 (B1802AYA), Ezeiza, Buenos Aires (Argentina)]. e-mail: pirchio@cae.cnea.gov.ar

    2006-07-01

    A new source of {sup 125} I model Braquibac{sup TM} has been developed in Argentina for applications in interstitial brachytherapy. The AAPM Task Group 43 (TG-43) recommends that dosimetric characteristics of new sources of brachytherapy of Iodine-125 have been theoretically and experimentally determined before its clinical use. The objectives outlined in this work were the study of the design of the new seed, the calculation of dosimetric parameters and the photons spectra analysis. Its were carried out radiographic and metallographic studies to determine the physical characteristics of the source. For the realization of the dosimetric calculations it was used the Monte Carlo code MCNP5. Values of the radial dose function, g(r), of the constant of dose rate, {lambda}, of the function of anisotropy of two dimensions, F(r, {theta}), of the factor and constant of anisotropy its were obtained simulating the source in water according to the recommended methodology in TG-43. The constant of dose rate is similar to 0,880 {+-} 0,080 c Gy h{sup -1} U{sup -1}. The kerma in air rate of reference, S{sub K}, was calculated as 1,036 c Gy cm{sup 2}h{sup -1} mCi{sup -1} simulating the seed in dry air. Its were carried out spectrometric studies using a semiconductor planar detector of HPGe (high purity germanium). Photons spectra showed characteristic x-rays of {sup 125} I with energies of 27,20 keV, 27,47 keV, 31 keV and 31,70 keV gamma photons of 35,5 keV, and x-ray fluorescent coming from the silver nucleus of 22,10 keV, 24,94 keV and 25,45 keV. The angular dependence of the intensity of photons around the seed and in air it was analyzed with the planar detector. This was carried out to study the anisotropy in the photons flow due to variation in the thickness of the titanium wall and of the welding, movements of the silver tube inside the source and deposition of the radioactive material on the silver tube. (Author)

  14. On the Origin of Microheterogeneity : Mass Spectrometric Studies of Acetonitrile-Water and Dimethyl Sulfoxide-Water Binary Mixtures (Part 2)

    NARCIS (Netherlands)

    Shin, Dong Nam; Wijnen, Jan W.; Engberts, Jan B.F.N.; Wakisaka, Akihiro

    2002-01-01

    The microscopic structures of acetonitrile-water and DMSO-water binary mixed solvents and their influence on the solvation for solutes (some alcohols and phenol) have been studied on the basis of the cluster structures observed through a specially designed mass spectrometer. In acetonitrile-water

  15. Spectrometric kidney depth measurement method

    International Nuclear Information System (INIS)

    George, P.; Soussaline, F.; Raynaud, C.

    1976-01-01

    The method proposed uses the single posterior surface measurement of the kidney radioactivity distribution. The ratio C/P of the number of scattered photons to the number of primary photons, which is a function of the tissue depth penetrated, is calculated for a given region. The parameters on which the C/P value depends are determined from studies on phantoms. On the basis of these results the kidney depth was measured on a series of 13 patients and a correlation was established between the value thus calculated and that obtained by the profile method. The reproducibility of the method is satisfactory [fr

  16. Mass spectrometric and chemometric studies of thermoplastic properties of coals. 1. Chemometry of conventional, solvent swelling and extraction data of coals

    Energy Technology Data Exchange (ETDEWEB)

    Marzec, A.; Czajkowska, S.; Moszynski, J.; Schulten, H.-R. (Polish Academy of Sciences, Gliwice (Poland). Inst. of Coal Chemistry)

    Twenty-seven coals from Carboniferous seams in Poland were studied with the aim to find links between thermoplastic properties and chemical characteristics of the coals. Three sets of data were obtained for all the coals: (1) thermoplastic properties measured using the Gieseler plastometer; (2) yields of pyridine extractables and swelling measurements for pyridine residues; (3) ultimate, proximate, and petrographic analyses. The three data sets were evaluated using chemometric techniques with the purpose of looking for significant correlations between all the data. Temperature of softening is a linear regression of pyridine extractables and hydrogen content in coals as well as of swelling data. Temperatures of maximum fluidity and resolidification are correlated with each other and with oxygen, exinite, and moisture contents of the coals as well as with the swelling data. It has been concluded that temperature of softening is a colligative property and indicates a phase transition resulting in an increase of thermal induced mobility of coal material; the energy demand of the transition is dependent on contents of bulk components of coal system that were specified in this study. Temperatures of maximum fluidity and resolidification appear to have the same chemical background; i.e. the temperatures depend on the content of the same structural units or components. However, the means of chemical characterization of coal material used in this study were not capable of identifying them. Volatile matter and petrographic composition showed rather limited value as predictive means for some (T{sub F(max)} and T{sub R}) and no predictive value for the other thermoplastic properties. 20 refs., 1 fig., 5 tabs.

  17. Mass Spectrometric Analysis for Nuclear Safeguards

    International Nuclear Information System (INIS)

    Boulyga, S.

    2013-01-01

    The release of man-made radionuclides into the environment results in contamination that carries specific isotopic signatures according to the release scenarios and the previous usage of materials and facilities. In order to trace the origin of such contamination and/or to assess the potential impact on the public and environmental health, it is necessary to determine the isotopic composition and activity concentrations of radionuclides in environmental samples in an accurate and timely fashion. Mass spectrometric techniques, such as thermal ionization mass spectrometry (TIMS), secondary ion mass spectrometry (SIMS), and inductively coupled plasma mass spectrometry (ICP-MS) belong to the most powerful methods for analysis of nuclear and related samples in nuclear safeguards, forensics, and environmental monitoring. This presentation will address the potential of mass spectrometric analysis of actinides at ultra-trace concentration levels, isotopic analysis of micro-samples, age determination of nuclear materials as well as identification and quantification of elemental and isotopic signatures of nuclear samples in general. (author)

  18. Spectrometric study of the folding process of i-motif-forming DNA sequences upstream of the c-kit transcription initiation site

    International Nuclear Information System (INIS)

    Bucek, Pavel; Gargallo, Raimundo; Kudrev, Andrei

    2010-01-01

    The c-kit oncogene shows a cytosine-rich DNA region upstream of the transcription initiation site which forms an i-motif structure at slightly acidic pH values (Bucek et al. ). In the present study, the pH-induced formation of i-motif - forming sequences 5'-CCC CTC CCT CGC GCC CGC CCG-3' (ckitC1, native), 5'-CCC TTC CCT TGT GCC CGC CCG-3' (ckitC2) and 5'-CCCTT CCC TTTTT CCC T CCC T-3' (ckitC3) was studied by spectroscopic techniques, such as UV molecular absorption and circular dichroism (CD), in tandem with two multivariate data analysis methods, the hard modelling-based matrix method and the soft modelling-based MCR-ALS approach. Use of the hard chemical modelling enabled us to propose the equilibrium model, which describes spectral changes as functions of solution acidity. Additionally, the intrinsic protonation constant, K in , and the cooperativity parameters, ω c , and ω a , were calculated from the fitting procedure of the coupled CD and molecular absorption spectra. In the case of ckitC2 and ckitC3, the hard model correctly reproduced the spectral variations observed experimentally. The results indicated that folding was accompanied by a cooperative process, i.e. the enhancement of protonated structure stability upon protonation. In contrast, unfolding was accompanied by an anticooperative process. Finally, folding of the native sequence, ckitC1, seemed to follow a more complex mechanism.

  19. Aerial gamma spectrometric survey as a tool for evaluating the uranium remobilization degree: Case study from Al-Awabed area, Northern Palmyrides, Syria

    International Nuclear Information System (INIS)

    Asfahani, J.; Al-Hent, R.; Aissa, M.

    2009-01-01

    The relationships between equivalent uranium (eU), eTh, K% and their ratios in the 11 lithological units determined by previous research in the Al-Awabed area, Northern Palmyrides, Syria have been analyzed in order to define their trend variations and evaluate the degree of uranium remobilization. Uranium favorability index U I and alteration-F indicators have been used in this research to characterize the different lithological units by following their radioactive element re-distribution and to determine their favorability as regards uranium potentiality. It was shown that uranium remobilization took place in all the lithological units, but to different degrees. This remobilization is qualified as weak, indicating that limited uranium redistribution is expected in the studied region. A plausible geological model is proposed for the uranium distribution, where the Abou Qila location is found to be favorable for uranium accumulation and merits further uranium exploration. (Authors)

  20. Gas chromatography-mass spectrometric studies of O-alkyl O-2-(N,N-dialkylamino) ethyl alkylphosphonites(phosphonates) for chemical weapons convention verification.

    Science.gov (United States)

    Saeidian, Hamid; Babri, Mehran; Ramezani, Atefeh; Ashrafi, Davood; Sarabadani, Mansour; Naseri, Mohammad Taghi

    2013-01-01

    The electron ionization (EI) mass spectra of a series of O-alkyl O-2-(N,N-dialkylaminolethyl alkylphosphonites(phosphonates), which are precursors of nerve agents, were studied for Chemical Weapons Convention (CWC) verification. General El fragmentation pathways were constructed and discussed. Proposed fragment structures were confirmed through analyzing fragment ions of deuterated analogs and density functional theory (DFT) calculations. The observed fragment ions are due to different fragmentation pathways such as hydrogen and McLafferty+1 rearrangements, alkene, amine and alkoxy elimination by alpha- or beta-cleavage process. Fragment ions distinctly allow unequivocal identification of the interested compounds including those of isomeric compounds. The presence and abundance of fragment ions were found to depend on the size and structure of the alkyl group attached to nitrogen, phosphorus and oxygen atoms.

  1. Compounds enhanced in a mass spectrometric profile of smokers' exhaled breath versus non-smokers as determined in a pilot study using PTR-MS.

    Science.gov (United States)

    Kushch, Ievgeniia; Schwarz, Konrad; Schwentner, Lukas; Baumann, Bettina; Dzien, Alexander; Schmid, Alex; Unterkofler, Karl; Gastl, Günter; Spaněl, Patrik; Smith, David; Amann, Anton

    2008-06-01

    A pilot study has been carried out to define typical characteristics of the trace gas compounds in exhaled breath of non-smokers and smokers to assist interpretation of breath analysis data from patients who smoke with respiratory diseases and lung cancer. Exhaled breath was analyzed using proton transfer reaction-mass spectrometry (PTR-MS) for 370 volunteers (81 smokers, 210 non-smokers, 79 ex-smokers). Volatile organic compounds corresponding to product ions at seven mass-to-charge ratios (m/z 28, 42, 69, 79, 93, 97, 123) in the PTR-MS spectra differentiated between smokers and non-smokers. The Youden index (= maximum of sensitivity + specificity - 1, YI) as a measure for differentiation between smokers and non-smokers was YI = 0.43 for ions at the m/z values 28 (tentatively identified as HCN), YI = 0.75 for m/z = 42 (tentatively identified as acetonitrile) and YI = 0.53 for m/z = 79 (tentatively identified as benzene). No statistically significant difference between smokers and non-smokers was observed for the product ions at m/z = 31 and 33 (compounds tentatively identified as formaldehyde and methanol). When interpreting the exhaled breath of lung cancer or COPD patients, who often smoke, compounds appearing at the above-mentioned seven mass-to-charge ratios should be considered with appropriate care to avoid misdiagnosis. Validation studies in larger numbers of patients with more precise delineation of their smoking behavior and using additional analytical techniques such as GC/MS and SIFT-MS should be carried out.

  2. Mechanistic study on lowering the sensitivity of positive atmospheric pressure photoionization mass spectrometric analyses: size-dependent reactivity of solvent clusters.

    Science.gov (United States)

    Ahmed, Arif; Choi, Cheol Ho; Kim, Sunghwan

    2015-11-15

    Understanding the mechanism of atmospheric pressure photoionization (APPI) is important for studies employing APPI liquid chromatography/mass spectrometry (LC/MS). In this study, the APPI mechanism for polyaromatic hydrocarbon (PAH) compounds dissolved in toluene and methanol or water mixture was investigated by use of MS analysis and quantum mechanical simulation. In particular, four different mechanisms that could contribute to the signal reduction were considered based on a combination of MS data and quantum mechanical calculations. The APPI mechanism is clarified by combining MS data and density functional theory (DFT) calculations. To obtain MS data, a positive-mode (+) APPI Q Exactive Orbitrap mass spectrometer was used to analyze each solution. DFT calculations were performed using the general atomic and molecular electronic structure system (GAMESS). The experimental results indicated that methanol significantly reduced the signal in (+) APPI, but no significative signal reduction was observed when water was used as a co-solvent with toluene. The signal reduction is more significant especially for molecular ions than for protonated ions. Therefore, important information about the mechanism of methanol-induced signal reduction in (+) APPI-MS can be gained due its negative impact on APPI efficiency. The size-dependent reactivity of methanol clusters ((CH3 OH)n , n = 1-8) is an important factor in determining the sensitivity of (+) APPI-MS analyses. Clusters can compete with toluene radical ions for electrons. The reactivity increases as the sizes of the methanol clusters increase and this effect can be caused by the size-dependent ionization energy of the solvent clusters. The resulting increase in cluster reactivity explains the flow rate and temperature-dependent signal reduction observed in the analytes. Based on the results presented here, minimizing the sizes of methanol clusters can improve the sensitivity of LC/(+)-APPI-MS. Copyright © 2015 John

  3. Effect of operation conditions of the drop-on-demand aerosol generator on aerosol characteristics: Pseudo-cinematographic and plasma mass spectrometric studies

    Science.gov (United States)

    Orlandini v. Niessen, Jan O.; Krone, Karin M.; Bings, Nicolas H.

    2014-02-01

    The recently presented drop-on-demand (DOD) aerosol generator overcomes some of the drawbacks of pneumatic nebulization, as its aerosol is no longer generated by gas-liquid interaction. In the current study, an advanced imaging technique is presented, based on a CCD camera equipped with magnifying telecentric optics to allow for fast, automated and precise aerosol characterization as well as fundamental studies on the droplet generation processes by means of pseudo-cinematography. The DOD aerosol generator is thoroughly characterized regarding its droplet size distribution, which shows few distinct populations rather than a continuous distribution. Other important figures, such as the Sauter diameter (D3,2) of 22 μm and the span of 0.4 were also determined. Additionally, the influence of the electrical operation conditions of the dosing device on the aerosol generation process is described. The number and volume of the generated droplets were found to be very reproducible and user-variable, e.g. from 17 to 27 μm (D3,2), within a span of 0.07-0.89. The performances of different setups of the DOD as liquid sample introduction system in ICP-MS are correlated to the respective achievable aerosol characteristics and are also compared to the performance of a state-of-the-art μ-flow nebulizer (EnyaMist). The DOD system allowed for improved sensitivity, but slightly elevated signal noise and overall comparable limits of detection. The results are critically discussed and future directions are outlined.

  4. Effect of operation conditions of the drop-on-demand aerosol generator on aerosol characteristics: Pseudo-cinematographic and plasma mass spectrometric studies

    International Nuclear Information System (INIS)

    Orlandini von Niessen, Jan O.; Krone, Karin M.; Bings, Nicolas H.

    2014-01-01

    The recently presented drop-on-demand (DOD) aerosol generator overcomes some of the drawbacks of pneumatic nebulization, as its aerosol is no longer generated by gas–liquid interaction. In the current study, an advanced imaging technique is presented, based on a CCD camera equipped with magnifying telecentric optics to allow for fast, automated and precise aerosol characterization as well as fundamental studies on the droplet generation processes by means of pseudo-cinematography. The DOD aerosol generator is thoroughly characterized regarding its droplet size distribution, which shows few distinct populations rather than a continuous distribution. Other important figures, such as the Sauter diameter (D 3,2 ) of 22 μm and the span of 0.4 were also determined. Additionally, the influence of the electrical operation conditions of the dosing device on the aerosol generation process is described. The number and volume of the generated droplets were found to be very reproducible and user-variable, e.g. from 17 to 27 μm (D 3,2 ), within a span of 0.07–0.89. The performances of different setups of the DOD as liquid sample introduction system in ICP-MS are correlated to the respective achievable aerosol characteristics and are also compared to the performance of a state-of-the-art μ-flow nebulizer (EnyaMist). The DOD system allowed for improved sensitivity, but slightly elevated signal noise and overall comparable limits of detection. The results are critically discussed and future directions are outlined. - Graphical abstract: Further characterization of the drop-on-demand aerosol generator for sample introduction in atomic spectrometry. - Highlights: • Significantly improved ICP-MS sensitivity using the DOD vs. EnyaMist. • Comparable detection limits but slightly worse short-term precision. • Superior flexibility compared with conventional/miniaturized pneumatic nebulizers. • Electrical operation conditions of the DOD influence aerosol characteristics.

  5. Effect of operation conditions of the drop-on-demand aerosol generator on aerosol characteristics: Pseudo-cinematographic and plasma mass spectrometric studies

    Energy Technology Data Exchange (ETDEWEB)

    Orlandini von Niessen, Jan O.; Krone, Karin M.; Bings, Nicolas H., E-mail: bings@uni-mainz.de

    2014-02-01

    The recently presented drop-on-demand (DOD) aerosol generator overcomes some of the drawbacks of pneumatic nebulization, as its aerosol is no longer generated by gas–liquid interaction. In the current study, an advanced imaging technique is presented, based on a CCD camera equipped with magnifying telecentric optics to allow for fast, automated and precise aerosol characterization as well as fundamental studies on the droplet generation processes by means of pseudo-cinematography. The DOD aerosol generator is thoroughly characterized regarding its droplet size distribution, which shows few distinct populations rather than a continuous distribution. Other important figures, such as the Sauter diameter (D{sub 3,2}) of 22 μm and the span of 0.4 were also determined. Additionally, the influence of the electrical operation conditions of the dosing device on the aerosol generation process is described. The number and volume of the generated droplets were found to be very reproducible and user-variable, e.g. from 17 to 27 μm (D{sub 3,2}), within a span of 0.07–0.89. The performances of different setups of the DOD as liquid sample introduction system in ICP-MS are correlated to the respective achievable aerosol characteristics and are also compared to the performance of a state-of-the-art μ-flow nebulizer (EnyaMist). The DOD system allowed for improved sensitivity, but slightly elevated signal noise and overall comparable limits of detection. The results are critically discussed and future directions are outlined. - Graphical abstract: Further characterization of the drop-on-demand aerosol generator for sample introduction in atomic spectrometry. - Highlights: • Significantly improved ICP-MS sensitivity using the DOD vs. EnyaMist. • Comparable detection limits but slightly worse short-term precision. • Superior flexibility compared with conventional/miniaturized pneumatic nebulizers. • Electrical operation conditions of the DOD influence aerosol

  6. Mass Spectrometric Study of Some Fluoroquinolone Drugs Using Electron Ionization and Chemical Ionization Techniques in Combination With Semi-Empirical Calculations

    International Nuclear Information System (INIS)

    Abd EL Kareem, M.S.M.

    2013-01-01

    A mass spectrometer of the type QMS (SSQ710) is used to record the electron ionization mass spectra of some 6-fluoroquinolones molecules, namely: Norfloxacin, Pefloxacin, Ciprofloxacin and Levofloxacin.While the chemical ionization mass spectra of these compounds are recorded using Thermo Finnigan TRACE DSQ GC/MS system.In EI mass spectra, the relative intensities for the molecular ions [M] +. of the studied compounds and the prominent fragment ions are reported and discussed. Furthermore, fragmentation patterns for the four compounds have been suggested and discussed and the most important fragmentation processes such as [M-CO 2 ] +. , [M-C 2 H 4 N] + and [M-CO 2 -C 2 H 4 N] + are investigated.On the other hand, the chemical ionization (CI) mass spectra of the compounds have been recorded using methane as the reagent gas. These spectra are discussed in terms of the structure of the compounds, with particular reference to their conventional electron ionization mass spectra. The protonated molecules [M + H] + are more relatively intense than [M] +. ions in the recorded EI mass spectra indicating higher stability in the case of [M + H] + .Also, fragmentation patterns for the four compounds have been suggested and discussed (using chemical ionization technique) and the most important fragmentation processes such as [MH-CO 2 ] +. , [MH-C 2 H 4 N] + and [MH-H 2 O] + are investigated.

  7. On-line Mass Spectrometric Study of Heavy-Ion Induced Reactions at Energies up to 86 MeV/amu

    CERN Multimedia

    2002-01-01

    The aim of the experiment was to measure isotopic distributions of Li, Na, K, Rb, Cs and Fr as reaction fragments in heavy ion collisions. In order to get an overall view of the new energy range for heavy ions available from the SC, different energies and projectile-target combinations had to be studied. The data taking status is now finished. |1|2C and |1|8O beams were used in bombarding |1|2C, |9|3Nb, |1|8|1Ta and |2|3|8U in order to look at target fragmentation, projectile fragmentation and evaporative residues of spallation processes. The experimental apparatus is composed of three parts: \\item a)~A target-oven-ionizer assembly where selective thermal diffusion and selective surface ionization takes place in order to obtain a chemical separation of the reaction products. \\item b)~The mass spectrometer where the different-mass fragments are selected. \\item c)~An electrostatic ion beam line through which the fragments are transported to a low-background area where the detector (an electron multiplier) is lo...

  8. Simultaneous determination of codeine, ephedrine, guaiphenesin and chlorpheniramine in beagle dog plasma using high performance liquid chromatography coupled with tandem mass spectrometric detection: application to a bioequivalence study.

    Science.gov (United States)

    Hu, Ziyan; Zou, Qiaogen; Tian, Jixin; Sun, Lili; Zhang, Zunjian

    2011-12-15

    A rapid and sensitive method based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the simultaneous determination of codeine, ephedrine, guaiphenesin and chlorpheniramine in beagle dog plasma has been developed and validated. Following liquid-liquid extraction, the analytes were separated on a reversed-phase C(18) column (150 mm × 2.0 mm, 3 μm) using formic acid:10 mM ammonium acetate:methanol (0.2:62:38, v/v/v) as mobile phase at a flow rate of 0.2 mL/min and analyzed by a triple-quadrupole mass spectrometer in the selected reaction monitoring (SRM) mode. The method was linear for all analytes over the following concentration (ng/mL) ranges: codeine 0.08-16; ephedrine 0.8-160; guaiphenesin 80-16,000; chlorpheniramine 0.2-40. Acceptable precision and accuracy were obtained for concentrations over the standard curve range. It is the first time that the validated HPLC-MS/MS method was successfully applied to a bioequivalence study in 6 healthy beagle dogs. Copyright © 2011 Elsevier B.V. All rights reserved.

  9. Study of systematic errors in the determination of total Hg levels in the range -5% in inorganic and organic matrices with two reliable spectrometrical determination procedures

    International Nuclear Information System (INIS)

    Kaiser, G.; Goetz, D.; Toelg, G.; Max-Planck-Institut fuer Metallforschung, Stuttgart; Knapp, G.; Maichin, B.; Spitzy, H.

    1978-01-01

    In the determiniation of Hg at ng/g and pg/g levels systematic errors are due to faults in the analytical methods such as intake, preparation and decomposition of a sample. The sources of these errors have been studied both with 203 Hg-radiotracer techniques and two multi-stage procedures developed for the determiniation of trace levels. The emission spectrometrie (OES-MIP) procedure includes incineration of the sample in a microwave induced oxygen plasma (MIP), the isolation and enrichment on a gold absorbent and its excitation in an argon plasma (MIP). The emitted Hg-radiation (253,7 nm) is evaluated photometrically with a semiconductor element. The detection limit of the OES-MIP procedure was found to be 0,01 ng, the coefficient of variation 5% for 1 ng Hg. The second procedure combines a semi-automated wet digestion method (HCLO 3 /HNO 3 ) with a reduction-aeration (ascorbic acid/SnCl 2 ), and the flameless atomic absorption technique (253,7 nm). The detection limit of this procedure was found to be 0,5 ng, the coefficient of variation 5% for 5 ng Hg. (orig.) [de

  10. Hptlc-densitometry mass spectrometric utilization in the chemical finger printing of herbal drugs-a case study on commiphora mukul (abstract)

    International Nuclear Information System (INIS)

    Musharaf, S.G.; Iqbal, N.; Gulzar, U.; Ali, A.; Choudhary, M.I.; Rahman, A.

    2011-01-01

    In Asia, particularly in the Indo-Pak sub-continent, plants have been used as sources of indigenous drugs for thousands of years. However, at the global level the traditional herbal medicines couldn't achieve significance in medical and scientific communities due to the lack of quantitative standardization and consistency. The quantitative analysis of medical plants by using TLC and HPTLC methods is increasingly popular as manufacturers, researchers, and drug regulatory authorities are recognizing their versatility and cost effectiveness. It has been demonstrated that these techniques can analyze even a mixture of 15 plants in a single analytical run. We have recently developed a HPTLC-densitometric method based on ICH (International Conference on Harmonization) recommendations for the analysis of hypolipidemic agents, E- and Z-guggulsterones and capable to separate both isomers from their conger, 17, (20)-dihydroguggulsterone (non-hypolipidemic agent) and therefore quantify the biomarker compounds precisely and equally applicable for the varieties of guggulsterone samples including resins, guggulipid and marketed formulations, for the first time. E- and Z-guggulsterones are the constituents of guggul or guggulu (Sanskrit), sticky gum resin obtained from the Mukul myrrh tree (Commiphora mukul), widely used in the traditional medicines, particularly in Ayurveda for the treatment of gout, arthritis, rheumatism, obesity and inflammation. Pharmacological studies showed that guggul lipid (45% ethyl acetate extract of guggul) lowers the blood lipids in patients and possessed clinically proved hypolipidemic activity. Moreover, Guggul helps to reduce high cholesterol, because it lowers harmful low density lipoproteins (LDL-proteins) while elevating the beneficial high density lipoproteins. It is well documented that the E- and Z-isomers of guggulsterones are the biomarker compounds, responsible the hypolipidemic activity. (author)

  11. Determination of actinides by alpha spectrometric methods

    International Nuclear Information System (INIS)

    Galanda, D.

    2011-01-01

    The submitted thesis in its first part concern with content determination of plutonium, americium, uranium, thorium radionuclides, like the most significant representatives of actinides in environmental patterns, where by the primary consideration is a focusing on content of these actinides in samples of superior mycotic organisms - mushrooms. Following the published studies the mushrooms were monitored as organisms that could verify most of attributes putted on bioindicators in term of observation of substantial radionuclides in living environment. There were analyzed two groups of samples that came from two chosen locations, one of them is situated in Eastern Slovakia and the second one in West Slovakia. Except for mushrooms samples the examined radionuclides volumes were determined even in specimens of soil sub-base and some plants from chosen localities. The liquid - liquid extraction methods were used for determination of mass activities of actinides in samples for radiochemical separation of monitored radionuclides. The obtained results of plutonium and americium mass activities determination's lead us to carry out experiments that proved abilities of superior mycotic organisms to absorb and accumulate alpha radionuclides in their textures. We choose the oyster mushroom (Pleurotus ostreatus) species as an experimental object. Sporocarps of this mushroom were cultivated on substratum which is commercially exploited to cultivate it whereby this substratum was purposely contaminated by known activities of 239 Pu and 241 Am. We prepared five autonomous samples together. The values of mass activities of 239 Pu and 241 Am obtained by following analysis of prepared samples showed the ability of mushrooms to absorb observed actinides in their texture structures. On the basis of obtained mass activities it was possible to evaluate and numerically determine a transmitting factor's attributes of monitored radionuclides in sporocarps and in sub-base. Accordingly we

  12. Moessbauer spectrometric data acquisition based on FPGA

    International Nuclear Information System (INIS)

    Zhang Yuan; Li Shimin; Chen Nan; Zhu Jingbo; Xia Yuanfu

    2008-01-01

    FPGA(Field Programmable Gate Array) is a programmable device with strong logical function and timing control ability. It is extremely potent in acquiring and processing timing signals. By replacing the traditional used SCM (Single-Chip Microcomputer) with FPGA, counting speed of Moessbauer spectrometric data acquisition can be improved markedly with significantly decreased size of the spectrometer. The counter, RAM and RS-232 communication of the module are developed on Altera Cyclone series chip EP1C6T144C8 with Quartus II. EP1C6T144C8 has 5980 logical units accompanied by 92160 bits of memory space. It is so powerful that all needs in data acquisition of the Moessbauer spectrometer can be perfectly satisfied while allowing modifications in functions and parameters. (authors)

  13. Gas Chromatography-Mass Spectrometric Analysis and Insecticidal ...

    African Journals Online (AJOL)

    HP

    Original Research Article. Gas Chromatography-Mass Spectrometric Analysis and ... into a natural fumigant/insecticide for the control of stored product insects. Keywords: Mallotus ..... stability as well as reduce cost. ACKNOWLEDGEMENT.

  14. Gas Chromatography-Mass Spectrometric Analysis of Nematicidal ...

    African Journals Online (AJOL)

    Gas Chromatography-Mass Spectrometric Analysis of Nematicidal Essential Oil of Valeriana ... Tropical Journal of Pharmaceutical Research ... have a potential to be developed to natural nematicides for the control of cereal cyst nematodes.

  15. Gas Chromatography-Mass Spectrometric Analysis and Insecticidal ...

    African Journals Online (AJOL)

    Tropical Journal of Pharmaceutical Research ... apelta aerial parts was analyzed by gas chromatography/mass spectrometric (GC/MS) to determine its composition. ... into a natural fumigant/insecticide for the control of stored product insects.

  16. Mass-spectrometric investigation of rare earth acetylacetonates dipivaloylmethanates and their adducts

    International Nuclear Information System (INIS)

    Gavrishzhuk, E.M.; Dzyubenko, N.G.; Martynenko, L.I.

    1985-01-01

    Peculiarities of fragmentation of molecular ions of rare earth acetylacetonates and dipivaloylmethanates under mass-spectrometric investigation of these compounds as well as their adducts with o-phenanthroline, α,α'-dipyridyl, triphenylphosphine oxide are considered in the given review. Similar data for identical derivants of some transitions metals are presented. Data on potentials of appearance and dissociation energy of basic ions in mass-spectra of the studied β-diketonates are analyzed

  17. The measurement of mass spectrometric peak height ratio of helium isotope in trace samples

    International Nuclear Information System (INIS)

    Sun Mingliang

    1989-01-01

    An experiment study on the measurement of mass spectrometric peak height ratio of helium isotope in the trace gaseous sample is discussed by using the gas purification line designed by the authors and model VG-5400 static-vacuum noble gas mass spectrometer imported and air helium as a standard. The results show that the amount of He and Ne in natural gas sample is 99% after purification. When the amount of He in Mass Spectrometer is more than 4 x 10 -7 cm 3 STP, it's sensitivity remains stable, about 10 -4 A/cm 3 STP He and the precision of 3 He/ 4 He ratio within the following 17 days is 1.32%. The 'ABA' pattern and experiment condition in the measurement of mass spectrometric peak height ratio of He isotope are presented

  18. Study of semi-conductor spectrometers for high counting rates. Application to the study of the reaction {sup 31}P (p, {alpha}{sub 0}): E{sub p} < 2 MeV; Etude de spectrometres a semi-conducteurs pour forts taux de comptage application a l'etude de la reaction {sup 31}P (p, {alpha}0): E{sub p} < 2 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Ligeon, E [Commissariat a l' Energie Atomique, 38 - Grenoble (France). Centre d' Etudes Nucleaires

    1967-10-01

    The study of nuclear reactions involving particles of low charge (E < 2 MeV) calls for spectrometers of high resolving power. In many experiments however, the counting rate is high because of Coulomb scattering at the target: this results in a distortion of the experimental spectra and a loss of resolving power in the detection equipment. The first part of the work is devoted to an evaluation of the resolving power obtained with silicon-detector spectrometers. A study of the elastic scattering of protons by {sup 31}P shows which are the factors limiting the resolving power. In the second part we examine the various types of spectrometer which can be used in the case of a high count-rate. We have built an apparatus which can be used for carrying out spectrometry on particles produced by nuclear reactions, for a total, count-rate of 10{sup 5} counts/sec. (author) [French] L'etude des reactions nucleaires avec particules chargees a basse energie (E < 2 MeV) exige des spectrometres de haute resolution. Cependant, dans de nombreuses experiences le taux de comptage est eleve, par suite de la diffusion coulombienne sur la cible; on observe alors une distorsion des spectres experimentaux et une perte de resolution de l'ensemble de detection. La premiere partie de ce travail est consacree a l'evaluation de la resolution obtenue avec des spectrometres utilisant des detecteurs au silicium. L'etude de la diffusion elastique des protons sur le {sup 31}P montre quels sont les facteurs qui limitent la resolution. Dans une deuxieme partie, nous etudions les differents types de spectrometres que l'on peut utiliser dans le cas d'un taux de comptage eleve. Nous avons construit un appareil qui permet de faire la spectrometrie de particules, provenant de reactions nucleaires, pour un taux de comptage total de 10{sup 5} c/s. (auteur)

  19. Study of semi-conductor spectrometers for high counting rates. Application to the study of the reaction {sup 31}P (p, {alpha}{sub 0}): E{sub p} < 2 MeV; Etude de spectrometres a semi-conducteurs pour forts taux de comptage application a l'etude de la reaction {sup 31}P (p, {alpha}0): E{sub p} < 2 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Ligeon, E. [Commissariat a l' Energie Atomique, 38 - Grenoble (France). Centre d' Etudes Nucleaires

    1967-10-01

    The study of nuclear reactions involving particles of low charge (E < 2 MeV) calls for spectrometers of high resolving power. In many experiments however, the counting rate is high because of Coulomb scattering at the target: this results in a distortion of the experimental spectra and a loss of resolving power in the detection equipment. The first part of the work is devoted to an evaluation of the resolving power obtained with silicon-detector spectrometers. A study of the elastic scattering of protons by {sup 31}P shows which are the factors limiting the resolving power. In the second part we examine the various types of spectrometer which can be used in the case of a high count-rate. We have built an apparatus which can be used for carrying out spectrometry on particles produced by nuclear reactions, for a total, count-rate of 10{sup 5} counts/sec. (author) [French] L'etude des reactions nucleaires avec particules chargees a basse energie (E < 2 MeV) exige des spectrometres de haute resolution. Cependant, dans de nombreuses experiences le taux de comptage est eleve, par suite de la diffusion coulombienne sur la cible; on observe alors une distorsion des spectres experimentaux et une perte de resolution de l'ensemble de detection. La premiere partie de ce travail est consacree a l'evaluation de la resolution obtenue avec des spectrometres utilisant des detecteurs au silicium. L'etude de la diffusion elastique des protons sur le {sup 31}P montre quels sont les facteurs qui limitent la resolution. Dans une deuxieme partie, nous etudions les differents types de spectrometres que l'on peut utiliser dans le cas d'un taux de comptage eleve. Nous avons construit un appareil qui permet de faire la spectrometrie de particules, provenant de reactions nucleaires, pour un taux de comptage total de 10{sup 5} c/s. (auteur)

  20. Gas chromatography of organic microcontaminants using atomic emission and mass spectrometric detection combined in one instrument (GC-AED/MS)

    NARCIS (Netherlands)

    Mol, H.G.J.; Hankemeier, T.; Brinkman, U.A.T.

    1999-01-01

    This study describes the coupling of an atomic-emission detector and mass-spectrometric detector to a single gas chromatograph. Splitting of the column effluent enables simultaneous detection by atomic-emission detection (AED) and mass spectrometry (MS) and yields a powerful system for the target

  1. Determination of radium isotopes by BaSO4 coprecipitation for the preparation of alpha-spectrometric sources

    International Nuclear Information System (INIS)

    Lozano, J.C.; Fernandez, F.; Gomez, J.M.G.

    1997-01-01

    A coprecipitation procedure for the preparation of α-spectrometric sources for radium, using BaSO 4 as carrier, has been applied to the determination of alpha radium isotopes in water samples. The use of 133 Ba as a suitable tracer for radium determination and possible losses of radon isotopes from the sources are studied and discussed. (author)

  2. An Attempt to automate the lithological classification of rocks using geological, gamma-spectrometric and satellite image datasets

    International Nuclear Information System (INIS)

    Fouad, M. K.; Mielik, M. L.; Gharieb, A. N.

    2004-01-01

    The present study aims essentially at proving that the application of the integrated airborne gamma spectrometric and satellite image data is capable of refining the mapped surface geology, and identification of anomalous zones of radioelement content that could provide favorable exploration targets for radioactive mineralizations.The application of the appropriate statistical technique to correlate between satellite image data and gamma-spectrometric data is of great significance in this respect. Experience shows that Landsat T M data in 7 spectral bands are successfully used in such studies rather than MSS. Multivariate statistical analysis techniques are applied to airborne spectrometric and different spectral Landsat T M data. Reduction of the data from n-dimensionality, both qualitatively as color composite image, and quantitatively, as principal component analysis, is performed using some statistical control parameters. This technique shows distinct efficiency in defining areas where different lit ho facies occur. An area located at the north of the Eastern Desert of Egypt, north of Hurgada town, was chosen to test the proposed technique of integrated interpretation of data of different physical nature. The reduced data are represented and interpreted both qualitatively and quantitatively. The advantages and limitations of applying such technique to the different airborne spectrometric, and Landsat T M data are identified. (authors)

  3. Radio spectrometric survey of un-surveyed areas in Syria

    International Nuclear Information System (INIS)

    Aissa, M.; Al-Hent, R; Jubeli, Y.

    2002-11-01

    The values and distribution of the radioelements e U, e Th, % K and Ur units in the surface geological formations of the west and south sectors of Syrian region, were estimated using carbone gamma ray spectrometric survey. The radiometric maps were prepared, as well as, many geological profiles, cross sections studied in different locations and geochemical samples were analyzed by laboratory gamma ray spectrometry and by x-ray diffractometry, the results of the all sets were compared. In general, the survey shows, low radioelement concentrations in the area, especially on basic rocks (Jabal Al-arab, Hawran) south Syria, and on ultra basic rocks (ophiolitic complex) north-west Syria, but there are some separate anomalous spots were connected with phosphate rocks, detected on cretaceous and Palaeogene age. Some times we noticed high radioelement concentrations haloes associated with fractured zones were already arise from secondary uranium mineralization, as a result of solutions movement through fissures in carbonatic and/or chalk like limestone rocks. finally, the obtained concentrations, represent a background values which has no significant importance for uranium exploration point of view. (author)

  4. Status of mass spectrometric radiocarbon detection at ETHZ

    Energy Technology Data Exchange (ETDEWEB)

    Seiler, Martin; Maxeiner, Sascha; Wacker, Lukas; Synal, Hans-Arno

    2015-10-15

    A prototype of a mass spectrometric radiocarbon detection instrument without accelerator stage was built for the first time and set into operation at ETH Zurich. The system is designed as an experimental platform to optimize performance of {sup 14}C detection at low ion energies and to study the most relevant processes that may limit system performance. The optimized stripper unit incorporates differential pumping to maintain a low gas outflow and a revised tube design to better match the phase space volume of the ion beam at low energies. The system is fully operational and has demonstrated true radiocarbon dating capabilities. The overall beam transmission through the stripper tube is about 40% for the 1{sup +} charge state. Radiocarbon analyses with an overall precision of 0.6% were obtained on a single sample under regular measurement conditions. By analyzing multiple targets of the same sample material an uncertainty level of 0.3% has been reached. The background level corresponds to a radiocarbon age of 40,000 years.

  5. Mass spectrometric investigation of vinyl-substituted organic boron compounds

    International Nuclear Information System (INIS)

    Tarielashvili, V.O.; Ordzhonikidze, K.G.; Parulava, L.P.; Vakhaniya, G.V.

    1992-01-01

    Mass spectrometric investigation of vinyl-substituted organic compounds was conducted. Ionization was performed by electron shock. Possibility of determining boron isotope content is all analyzed organic boron vinyl-substituted compounds by direct method is shown. This simplifies sufficiently and lowers the price of analysis, improves its accuracy and rapidity

  6. Spectrometric determination of ammonium-nitrogen with quinol in ...

    African Journals Online (AJOL)

    Quinol is proposed as a reagent for the spectrometric determination of ammonium-nitrogen (NH4+-N) in aqueous medium. Quinol forms a pink complex with ammonium salt in aqueous medium. Hydrogen peroxide is needed for colour accentuation. The quinol/ammonium charge transfer complex has absorption maximum ...

  7. Interpretation of Spectrometric Measurements of Active Geostationary Satellites

    Science.gov (United States)

    Bedard, D.; Wade, G.

    2014-09-01

    Over 5000 visible near-infrared (VNIR) spectrometric measurements of active geostationary satellites have been collected with the National Research Council (NRC) 1.8m Plaskett telescope located at the Dominion Astrophysical Observatory (DAO) in Victoria, Canada. The objective of this ongoing experiment is to study how reflectance spectroscopy can be used to reliably identify specific material types on the surface of artificial Earth-orbiting objects. Active geostationary satellites were selected as the main subjects for this experiment since their orientation is stable and can be estimated to a high-level of confidence throughout a night of observation. Furthermore, for most geostationary satellites, there is a wide variety of sources that can provide some level of information as to their external surface composition. Notwithstanding the high number of measurements that have been collected to date, it was assumed that the experimenters would have a much greater success rate in material identification given the choice experimental subjects. To date, only the presence of aluminum has been confidently identified in some of the reflectance spectra that have been collected. Two additional material types, namely photovoltaic cells and polyimide film, the first layer of multi-layer insulation (MLI), have also been possibly identified. However uncertainties in the reduced spectral measurements prevent any definitive conclusion with respect to these materials at this time. The surprising lack of results with respect to material identification have forced the experimenters to use other data interpretation methods to characterize the spectral scattering characteristics of the studied satellites. The results from this study have already led to improvements in the ways that reflectance spectra from spacecraft are collected and analysed. Equally important, the data interpretation techniques elaborated over the course of this experiment will also serve to increase the body of

  8. Analysis of electrocautery generated smoke by chromatographic-mass spectrometry.

    Science.gov (United States)

    Kalil, Jefferson; Pessine, Francisco B T; Fidelis, Carlos H V; Menezes, Fabio H; Palma, Paulo Cesar Rodrigues

    2016-01-01

    to analyze the chemical components of the smoke from electrocautery from coagulating muscle and liver tissues of pigs. we collected smoke produced by electrocautery applied to porcine tissue in previously evacuated bottles, with qualitative and quantitative analysis of the compounds present through the hyphenated technique gas chromatography / mass spectrometry. there was a majority of decanal aldehyde in the fumes from the subcutaneous, muscle and liver tissues. Fumes of subcutaneous and muscular tissues also showed the presence of hexanal and phenol. In the fumes of subcutaneous and liver tissues we also found toluene and limonene and, finally, nonanal smoke was present in the muscle and liver tissues. there is increasing evidence showing that smoke from electrocautery used in subcutaneous, muscle and liver tissue is harmful to human health. Thus, there is need to reduce exposure to it or wear masks with filters capable of retaining these particles. analisar quimicamente os componentes da fumaça do eletrocautério, provenientes da coagulação de tecidos, muscular e hepático de suino. coleta de fumaça produzida por eletrocauterização de tecido porcino em frascos previamente evacuados com análise qualitativa e quantitativa dos compostos presentes, através de técnica hifenada, cromatografia a gás/espectrometria de massas. houve presença majoritária do aldeído decanal nas fumaças provenientes dos tecidos subcutâneo, muscular e hepático. Fumaças dos tecidos subcutâneo e muscular mostraram também a presença de hexanal e fenol. Nas fumaças dos tecidos subcutâneo e hepático foram encontrados ainda tolueno e limoneno e, por fim, nonanal estava presente nas fumaças dos tecidos muscular e hepático. há número crescente de evidências mostrando que fumaça proveniente de eletrocauterização de tecidos subcutâneo, muscular e hepático é nociva à saúde de seres humanos. Portanto, há necessidade de reduzir a exposição a ela ou usar máscara com filtro capaz de reter essas partículas.

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

    International Nuclear Information System (INIS)

    Udoh, Anthony P.

    2000-01-01

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

  10. Efficiency and attenuation correction factors determination in gamma spectrometric assay of bulk samples using self radiation

    International Nuclear Information System (INIS)

    Haddad, Kh.

    2009-02-01

    Gamma spectrometry forms the most important and capable tool for measuring radioactive materials. Determination of the efficiency and attenuation correction factors is the most tedious problem in the gamma spectrometric assay of bulk samples. A new experimental and easy method for these correction factors determination using self radiation was proposed in this work. An experimental study of the correlation between self attenuation correction factor and sample thickness and its practical application was also introduced. The work was performed on NORM and uranyl nitrate bulk sample. The results of proposed methods agreed with those of traditional ones.(author)

  11. Gamma Spectrometric Determination of U, Th, K and Some Geochemical Applications

    International Nuclear Information System (INIS)

    Dodona, A.; Tashko, A.

    2001-01-01

    The application of 'in situ' gamma-spectrometric method (''infinite'' environment), made possible the simultanious determination of U, Th and K. 4 channel gamma-spectrometric analyser with NaI(TI) scintilation counter crystal detector (103 cm 3 φ=50x50mm) was used to determin U, Th(more than 1-2 ppm) and K (more than 1%) in laboratory conditions. The detector was inserted into a lead camera and calibrated for measurement geometry with vessel of ''Marineli'' type of a 17o cm 3 volume. The study of main factors, which influence in the gamma spectrometric measurements, (the technical, physical, geometrical and time parameters) has been carried out. International standards of U, Th, K and internal monitoring standard samples are used for the calibration. External analytical control has been realized by other radiometric and chemical methods. The detection limits ( 1 ppm Th, 2ppm U and 1% K) and the relative errors (17-20% for 1-10 ppm U, Th and 10-15% for more than 10 ppm U, Th and more than 1% K) guarantee a quantitative analysis that may be used successfully in the geochemical studies. Some geochemical applications, based on the content of Th, U and Th/U ratio in rocks samples that we have we have analyzed with this method, are shown in this paper. U, Th and their ratio are used as trace elements to indicate the differences between the acidic magmatic rocks of Albania (Th/U ratio=2-6 and>10). The bimodal character of Th/U scattering in ignimbrides and monzonites (Korabi zone) shows that in addition to the ''normal'' rocks, there are also some ones enriched with Th, So, the differential analysis of Th, U, and K may be used as geochemical exploration criteria for the radioactive and non-radioactive mineralization, such as REE (Rare Earth Elements), phospghorites, bauxites, placers etc. (authors)

  12. System for Gamma an X rays fluorescence spectrometric

    International Nuclear Information System (INIS)

    Alonso Abad, D.; Arista Romeu, E.; Bolanos Perez, L. and others

    1997-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Lajos Kovács

    2012-07-01

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

  14. Gamma spectrometric system based on the personal computer Pravetz-83

    International Nuclear Information System (INIS)

    Yanakiev, K; Grigorov, T.; Vuchkov, M.

    1985-01-01

    A gamma spectrometric system based on a personal microcomputer Pravets-85 is described. The analog modules are NIM standard. ADC data are stored in the memory of the computer via a DMA channel and a real-time data processing is possible. The results from a series of tests indicate that the performance of the system is comparable with that of comercially avalable computerized spectrometers Ortec and Canberra

  15. Neutron activation and mass spectrometric measurement of /sup 129/I

    International Nuclear Information System (INIS)

    Strebin, R.S. Jr.; Brauer, F.P.; Kaye, J.H.; Rapids, M.S.; Stoffels, J.J.

    1987-11-01

    An integrated procedure has been developed for measurement of /sup 129/I by neutron activation analysis and mass spectrometry. An iodine isolation procedure previously used for neutron activation has been modified to provide separated iodine suitable for mass spectrometric measurement as well. Agreement between both methods has been achieved within error limits. The measurement limit by each method is about 10/sup 7/ atoms (2 fg) of /sup 129/I. 13 refs,. 4 figs., 1 tab

  16. Comparison of accelerator mass spectrometric measurement with liquid scintillation counting measurement for the determination of 14C in environmental samples

    International Nuclear Information System (INIS)

    Yasuike, Kaeko; Yamada, Yoshimune; Amano, Hikaru

    2010-01-01

    The concentrations of organically-bound 14 C in tree-ring cellulose of a Japanese Black Pine grown in Shika-machi (37.0 deg. N, 136.8 deg. E) and those of a Japanese Cedar grown in Kanazawa (36.5 deg. N, 136.7 deg. E), Japan, were analyzed for the ring-years from 1989 to 1998 by the accelerator mass spectrometric measurement. The results were compared with those of the same samples analyzed by the liquid scintillation counting measurement to determine the reliability of liquid scintillation counting measurement. An important result of this study is that the sensitivity and reproducibility of accelerator mass spectrometric measurement was almost equal to that of liquid scintillation counting measurement.

  17. Mass spectrometric detection of siRNA in plasma samples for doping control purposes.

    Science.gov (United States)

    Kohler, Maxie; Thomas, Andreas; Walpurgis, Katja; Schänzer, Wilhelm; Thevis, Mario

    2010-10-01

    Small interfering ribonucleic acid (siRNA) molecules can effect the expression of any gene by inducing the degradation of mRNA. Therefore, these molecules can be of interest for illicit performance enhancement in sports by affecting different metabolic pathways. An example of an efficient performance-enhancing gene knockdown is the myostatin gene that regulates muscle growth. This study was carried out to provide a tool for the mass spectrometric detection of modified and unmodified siRNA from plasma samples. The oligonucleotides are purified by centrifugal filtration and the use of an miRNA purification kit, followed by flow-injection analysis using an Exactive mass spectrometer to yield the accurate masses of the sense and antisense strands. Although chromatography and sensitive mass spectrometric analysis of oligonucleotides are still challenging, a method was developed and validated that has adequate sensitivity (limit of detection 0.25-1 nmol mL(-1)) and performance (precision 11-21%, recovery 23-67%) for typical antisense oligonucleotides currently used in clinical studies.

  18. The downfall of TBA-354 - a possible explanation for its neurotoxicity via mass spectrometric imaging.

    Science.gov (United States)

    Ntshangase, Sphamandla; Shobo, Adeola; Kruger, Hendrik G; Asperger, Arndt; Niemeyer, Dagmar; Arvidsson, Per I; Govender, Thavendran; Baijnath, Sooraj

    2017-10-13

    1. TBA-354 was a promising antitubercular compound with activity against both replicating and static Mycobacterium tuberculosis (M.tb), making it the focal point of many clinical trials conducted by the TB Alliance. However, findings from these trials have shown that TBA-354 results in mild signs of reversible neurotoxicity; this left the TB Alliance with no other choice but to stop the research. 2. In this study, mass spectrometric methods were used to evaluate the pharmacokinetics and spatial distribution of TBA-354 in the brain using a validated liquid chromatography tandem-mass spectrometry (LCMS/MS) and mass spectrometric imaging (MSI), respectively. Healthy female Sprague-Dawley rats received intraperitoneal (i.p.) doses of TBA-354 (20 mg/kg bw). 3. The concentrationtime profiles showed a gradual absorption and tissue penetration of TBA-354 reaching the C max at 6 h post dose, followed by a rapid elimination. MSI analysis showed a time-dependent drug distribution, with highest drug concentration mainly in the neocortical regions of the brain. 4. The distribution of TBA-354 provides a possible explanation for the motor dysfunction observed in clinical trials. These results prove the importance of MSI as a potential tool in preclinical evaluations of suspected neurotoxic compounds.

  19. Determination of trace quantities of uranium in rocks mass spectrometric isotope dilution technique

    International Nuclear Information System (INIS)

    Kakazu, Mauricio Hiromitu

    1980-01-01

    A detailed experimental investigation on the thermionic emission of uranium deposited on a single flat type rhenium filament has been carried out. The study was aimed at determining the influence of various forms of deposition on the emission sensitivity and thermal stability of U + , UO + and UO 2 + ions. Based on these investigations, a technique, involving an addition of a small quantity of colloidal suspension of graphite on top of the uranyl nitrate sample deposited, was chosen because of its higher, emission sensitivity for uranium metal ions. The experimental parameters of the technique were optimised and the technique was employed in the determination of trace quantities of uranium in rock samples using mass spectrometric isotope dilution method. For the mass spectrometric isotope dilution analysis National Bureau of Standards uranium isotopic standard NBS-U 970 was employed as a tracer, where as the mass discrimination effect in the uranium isotope analysis was corrected using the uranium isotopic standard NBS-U500. Uranium was determined in each of the seven granite samples from Wyoming, USA and two USGS standard rocks. The precision of the analysis was found to be ±1% . The uranium values obtained on the rock samples were compared with the analyses of other investigators. Influence of the sample splitting on the uranium analysis was discussed in the light of the analytical results obtained.(author)

  20. Liquid Chromatography Electrospray Ionization Tandem Mass Spectrometric (LC/ESI-MS/MS) Study for the Identification and Characterization of In Vivo Metabolites of Cisplatin in Rat Kidney Cancer Tissues: Online Hydrogen/Deuterium (H/D) Exchange Study.

    Science.gov (United States)

    Bandu, Raju; Ahn, Hyun Soo; Lee, Joon Won; Kim, Yong Woo; Choi, Seon Hee; Kim, Hak Jin; Kim, Kwang Pyo

    2015-01-01

    In vivo rat kidney tissue metabolites of an anticancer drug, cisplatin (cis-diamminedichloroplatinum [II]) (CP) which is used for the treatment of testicular, ovarian, bladder, cervical, esophageal, small cell lung, head and neck cancers, have been identified and characterized by using liquid chromatography positive ion electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) in combination with on line hydrogen/deuterium exchange (HDX) experiments. To identify in vivo metabolites, kidney tissues were collected after intravenous administration of CP to adult male Sprague-Dawley rats (n = 3 per group). The tissue samples were homogenized and extracted using newly optimized metabolite extraction procedure which involves liquid extraction with phosphate buffer containing ethyl acetate and protein precipitation with mixed solvents of methanol-water-chloroform followed by solid-phase clean-up procedure on Oasis HLB 3cc cartridges and then subjected to LC/ESI-HRMS analysis. A total of thirty one unknown in vivo metabolites have been identified and the structures of metabolites were elucidated using LC-MS/MS experiments combined with accurate mass measurements. Online HDX experiments have been used to further support the structural characterization of metabolites. The results showed that CP undergoes a series of ligand exchange biotransformation reactions with water and other nucleophiles like thio groups of methionine, cysteine, acetylcysteine, glutathione and thioether. This is the first research approach focused on the structure elucidation of biotransformation products of CP in rats, and the identification of metabolites provides essential information for further pharmacological and clinical studies of CP, and may also be useful to develop various effective new anticancer agents.

  1. Mass spectrometric analysis of simple hydrogen compounds; Analyse de composes hydrogenes simples au spectrometre de masse

    Energy Technology Data Exchange (ETDEWEB)

    Nief, C; Botter, R [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    A uranium furnace is inserted in the gas inlet line of a mass spectrometer between the leak and the source. The line is fed with simple hydrogen compounds (H{sub 2}O, NH{sub 3}, H{sub 2}S) which are in this way reduced to hydrogen gas. Memory effects are largely avoided by heating the sample line to 90 deg. C. The speed of the isotopic analysis is only slightly less than that of hydrogen gas itself; the accuracy is better due to the reduction of fractionating effects in the leak. For the absolute measurements of deuterium in water, the presence of H{sub 3}{sup +} is a problem. Water samples, prepared by mixing an unknown light water sample with different amounts of heavy water, are equilibrated with hydrogen sulphide and analysis of the two phases of each sample enables the zero of the concentration scale to be determined from the point of intersection of the two curves obtained by plotting mixture composition against the observed isotope ratio in the two phases. The whole experiment can be carried out in the apparatus described which analyses hydrogen in H{sub 2}S and H{sub 2}O in the same way. (author) [French] Un four a uranium est insere dans la ligne d'introduction de gaz d'un spectrometre de masse entre la fuite et la source. La ligne est alimentee par des composes hydrogenes simples (H{sub 2}O, NH{sub 3}, H{sub 2}S) qui sont de cette facon transformes en hydrogene gazeux. On evite dans une large mesure les effets de memoire en chauffant la ligne de l'echantillon jusqu'a 90 deg. C. La vitesse de l'analyse isotopique est seulement legerement inferieure a celle de l'hydrogene gazeux lui-meme; la precision est meilleure du fait de la reduction des effets de fractionnement dans la fuite. Pour les mesures absolues du deuterium dans l'eau, la presence de H{sub 3}{sup +} pose un probleme. Les echantillons d'eau, prepares en melangeant un echantillon inconnu d'eau legere a differentes quantites d'eau lourde, sont equilibres par de l'hydrogene sulfure et l'analyse de

  2. Photometric and emission-spectrometric determination of boron in steels

    International Nuclear Information System (INIS)

    Thierig, D.

    1982-01-01

    A method for the photometric determination of boron in unalloyed and alloyed steels is described, in which Curcumine is used as reagent. A separation of boron is not necessary. Limit of detection: 0.0003% B. The decomposition of boron nitride in the steel is achieved by heating the whole sample in fuming sulphuric acid/phosphoric acid. For the emission spectrometric investigation of solid steel samples and for the spectrochemical analysis of solutions with plasma excitation working parameters are given and possibilities of interferences are demonstrated. (orig.) [de

  3. Gamma spectrometric analyses of environmental samples at PINSTECH

    International Nuclear Information System (INIS)

    Faruq, M.U.; Parveen, N.; Ahmed, B.; Aziz, A.

    1979-01-01

    Gamma spectrometric analyses of air and other environmental samples from PINSTECH were carried out. Air particulate samples were analyzed by a Ge(Li) detector on a computer-based multichannel analyzer. Other environmental samples were analyzed by a Na(T1) scintillation detector spectrometer and a multichannel analyzer with manual analysis. Concentration of radionuclides in the media was determined and the sources of their production were identified. Age of the fall out was estimated from the ratios of the fission products. (authors)

  4. Determination of uranium enrichment by using gamma-spectrometric methods

    International Nuclear Information System (INIS)

    Kutnyj, D.V.; Telegin, Yu.N.; Odejchuk, N.P.; Mikhailov, V.A.; Tovkanets, V.E.

    2009-01-01

    By using commercial analysis programs MGAU (LLNL, USA) and FRAM (LANL, USA) the summary error of gamma-spectrometric uranium enrichment measurements was investigated. Uranium samples with enrichments of 0,71; 4,46 and 20,1 % were measured. The coaxial high purity germanium detector (type GC) and the planar germanium detector (type LEGe) were used as gamma-radiation detectors. It was shown that experimental equipment and mathematical software available in NSC KIPT allow us to measure uranium enrichment by nondestructive method with accuracy of not worse than 2%.

  5. Mass spectrometric analysis of protein interactions

    DEFF Research Database (Denmark)

    Borch, Jonas; Jørgensen, Thomas J. D.; Roepstorff, Peter

    2005-01-01

    Mass spectrometry is a powerful tool for identification of interaction partners and structural characterization of protein interactions because of its high sensitivity, mass accuracy and tolerance towards sample heterogeneity. Several tools that allow studies of protein interaction are now...... available and recent developments that increase the confidence of studies of protein interaction by mass spectrometry include quantification of affinity-purified proteins by stable isotope labeling and reagents for surface topology studies that can be identified by mass-contributing reporters (e.g. isotope...... labels, cleavable cross-linkers or fragment ions. The use of mass spectrometers to study protein interactions using deuterium exchange and for analysis of intact protein complexes recently has progressed considerably....

  6. MASS SPECTROMETRIC ANALYSIS FOR THE IDENTIFICATION OF THUNNUS GENUS FOUR SPECIES

    Directory of Open Access Journals (Sweden)

    T. Pepe

    2011-01-01

    Full Text Available An accurate identification of similar fish species is necessary to prevent illegal substitution and is imposed by labeling regulations in UE countries (1. The genus Thunnus comprises many species of different quality and commercial value. The increasing trade of fish preparations of the species included in this genus and the consequent loss of the external anatomical and morphological features enables fraudulent substitutions. This study reports data relating to the proteomic analysis of four tuna species (T. thynnus, T. alalunga, T. albacares, T. obesus. Sarcoplasmic proteins were studied by mono and two dimensional electrophoresis. The most significant proteins for the characterization of the species were analyzed by mass spectrometric techniques. As reported in a previous study (2, an accurate identification of the species seems possible, owing to the polymorphism displayed by the species of the Thunnus genus.

  7. Quantitative mass-spectrometric analysis of hydrogen helium isotope mixtures

    International Nuclear Information System (INIS)

    Langer, U.

    1998-12-01

    This work deals with the mass-spectrometric method for the quantitative analysis of hydrogen-helium-isotope mixtures, with special attention to fusion plasma diagnostics. The aim was to use the low-resolution mass spectrometry, a standard measuring method which is well established in science and industry. This task is solved by means of the vector mass spectrometry, where a mass spectrum is repeatedly measured, but with stepwise variation of the parameter settings of a quadruple mass spectrometer. In this way, interfering mass spectra can be decomposed and, moreover, it is possible to analyze underestimated mass spectra of complex hydrogen-helium-isotope mixtures. In this work experimental investigations are presented which show that there are different parameters which are suitable for the UMS-method. With an optimal choice of the parameter settings hydrogen-helium-isotope mixtures can be analyzed with an accuracy of 1-3 %. In practice, a low sensitivity for small helium concentration has to be noted. To cope with this task, a method for selective hydrogen pressure reduction has been developed. Experimental investigations and calculations show that small helium amounts (about 1 %) in a hydrogen atmosphere can be analyzed with an accuracy of 3 - 10 %. Finally, this work deals with the effects of the measuring and calibration error on the resulting error in spectrum decomposition. This aspect has been investigated both in general mass-spectrometric gas analysis and in the analysis of hydrogen-helium-mixtures by means of the vector mass spectrometry. (author)

  8. Mass spectrometric analysis of EPO IEF-PAGE interfering substances in nitrile examination gloves.

    Science.gov (United States)

    Reichel, Christian

    2012-10-01

    Direct detection of doping with recombinant erythropoietins (rhEPO) is accomplished by isoelectric focusing (IEF) or sodium dodecylsulfate (SDS) polyacrylamide gel electrophoresis (PAGE). In a recent publication, Lasne et al. (Electrophoresis 2011, 32, 1444) showed that improper use of nitrile examination gloves during sample collection, sample preparation, and IEF-PAGE may lead to distorted or absent EPO IEF-profiles. In order to clarify which substances are responsible for this observation, a mass spectrometric study on water extractable compounds found in nitrile gloves was performed. Several substance classes were shown to be present, among them polyethylene glycols (PEG), anionic and nonionic surfactants, as well as alcohol ethoxylates and plasticizers. It could be demonstrated that alkylbenzenesulfonates, the main category of detectable anionic detergents, and among them sodium dodecylbenzenesulfonate (SDBS) and its homologs, are the prime reason for the interference of nitrile gloves with EPO IEF-PAGE. Copyright © 2012 John Wiley & Sons, Ltd.

  9. Calibration of a leak detection spectrometer; Calibration d'un spectrometre detecteur de fuites

    Energy Technology Data Exchange (ETDEWEB)

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

    1958-07-01

    This paper describes a study of the possible methods for calibrating a leak detection spectrometer, and the estimation of outputs from the leaks is considered. With this in mind the question of sensitivity of leak detection is tackled on a very general level; first the sensitivity of the isolated instrument is determined, and then the sensitivity of an instrument connected to an installation where leaks may be suspected. Finally, practical solutions are proposed. (author) [French] Dans cet article, nous etudions les methodes possibles de calibration d'un spectrometre detecteur de fuites et nous envisageons l'evaluation des debits de fuites trouves. Pour cela, nous abordons la notion de sensibilite de la detection de fuite sur un plan tres general; d'abord nous determinons la sensibilite de l'appareil isole, ensuite la sensibilite d'un appareil connecte sur une installation ou l'on cherche les fuites. Enfin, nous preconisons des solutions pratiques. (auteur)

  10. Anomalies from aerial spectrometric and total count radiometric surveys in the southeastern United States

    International Nuclear Information System (INIS)

    Lee, C.H.; Lawton, D.E.

    1978-01-01

    Aerial radiometric reconnaissance surveys are conducted because of their cost, time, and manpower savings compared to surface studies. Two types of aerial surveys are being flown in the southeastern United States: total count gamma-ray surveys for the Coastal Plains Regional Commission and the US Geological Survey, and differential gamma-ray spectrometric surveys for the US Department of Energy. Anomalous radioactivity detected during aerial surveys is related to higher concentrations of naturally occurring uranium, or to cultural activities, natural causes, or mapping errors which simulate real uranium anomalies. Each anomaly should be ground checked; however, several types of anomalies may be eliminated by evaluation of the aerial data in the office if field time is limited

  11. Sr isotope geochemistry of East Alpine mineral deposits and mass spectrometric analyses of fluid inclusions

    International Nuclear Information System (INIS)

    Grum, W.

    1995-05-01

    Strontium isotope geochemistry and deformational history of selected carbonate-hosted deposits from different tectonic positions in the Eastern Alps were studied. In this context an equipment has been constructed to analyze the composition of volatile components of fluid inclusions (FI). Based on the results of Sr-isotopic investigations two groups of deposits are discriminated: Deposits formed by formation waters and/or metamorphogenic fluids: Tux (magnesite, scheelite), Otterzug (barite), Lassing (magnesite), Rabenwald (talc), Laussa and Mooseck (fluorite). The mineralizing fluids are derived from different sedimentary rock series and therefore 87 Sr/ 86 Sr-ratios vary between 0.707 and 0.719. Deposits situated along fault zones: Lassing (talc), Gasteiner Tal (Silberpfennig area; gold), Schlaining (stibnite) and Waldenstein (specularite). Sr isotope ratios of the mineralizing fluids from Lassing, Waldenstein and Schlaining ranges from 0.7112 to 0.7127 and are therefore thought to have scavenged the East Alpine crystalline. The mineralizing solutions of the Gasteiner Tal deposit may either have equilibrated with low radiogenic sedimentary or with (ultra-)basic rocks. A cracking chamber has been constructed in order to open FI by cracking for mass spectrometric analysis of volatile components. Gases are analysed using a quadrupole mass spectrometer. The desorption of gas from metal and sample surfaces during cracking can be neglected. The amount of gas released from the mineral lattices was studied. With that fast method ore bearing from barren host rocks have been distinguished by different composition of the FI at the Brixlegg barite mineralization (Eastern Alps). Within the Galway fluorite deposit (Ireland) different fluids were involved and mass spectrometric analysis were carried out to characterize these different fluids and to identify their origin. (author)

  12. Mass spectrometric methods for trace analysis of metals

    International Nuclear Information System (INIS)

    Bahr, U.; Schulten, H.R.

    1981-01-01

    A brief outline is given of the principles of mass spectrometry (MS) and the fundamentals of qualitative and quantitative mass spectrometric analysis emphasizing recent developments and results. Classical methods of the analysis of solids, i.e. spark-source MS and thermal ionization MS, as well as recent methods of metal analysis are described. Focal points in this survey of recently developed techniques include secondary ion MS, laser probe MS, plasma ion source MS, gas discharge MS and field desorption MS. Here, a more detailed description is given and the merits of these emerging methods are discussed more explicitly. In particular, the results of the field desorption techniques in elemental analyses are reviewed and critically evaluated

  13. 5th colloquium on atomic spectrometric trace analysis

    International Nuclear Information System (INIS)

    Welz, B.

    1989-01-01

    This book deals with apparatus, use-oriented and theoretical aspects of trace analysis and spectroscopy. General articles are concerned with the analysis of environmentally relevant samples; a comparison of modern spectroscopic techniques, the coupling of hydride production, chromatography and spectrometry; chemical modifiers for graphite tube furnace atomic absorption spectroscopy (AAS), and possible applications of flow injection to atomic spectrometric trace analysis - one of the outstanding subjects of the colloquium. About one quarter of the 85 contributions deals with new techniques including flow injection. Other priority subjects are the theory and application of graphite tube furnace AAS, and a comparison between different dissolution methods and direct solid analysis. Medicine and toxicology, analysis of biological materials and environmentally relevant samples are in the foreground of use-oriented papers. (orig./BBR) [de

  14. Modern spectrometric methods for the analysis of labelled compounds

    International Nuclear Information System (INIS)

    Kaspersen, F.M.; Funke, C.W.; Wagenaars, G.N.; Jacobs, P.L.

    1988-01-01

    A proper analysis of chemical compounds should give information about the chemical identity (not only the structure but also enantiomeric form), the chemical purity and chemical composition (e.g. giving information about counter-ions, solvents of crystallization). For labelled compounds information is also needed about isotopic purity (defined as the % of isotope present in the compound), the position/distribution of the isotope in the molecule and degree of labelling/specific activity. In the past ten years the possibilities for spectrometric analyses of labelled compounds have increased enormously and this chapter will give an overview of these methods with the exception of (radio)chromatography that will be dealt with in another chapter. (author)

  15. Realisation of a {beta} spectrometer solenoidal and a double {beta} spectrometer at coincidence; Realisation d'un spectrometre {beta} solenoidal et d'un double spectrometre {beta} a coincidence

    Energy Technology Data Exchange (ETDEWEB)

    Moreau, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1955-06-15

    The two spectrometers have been achieved to tackle numerous problems of nuclear spectrometry. They possess different fields of application that complete themselves. The solenoidal spectrometer permits the determination of the energy limits of {beta} spectra and of their shape; it also permits the determination of the coefficients of internal conversion and reports {alpha}{sub K} / {alpha}{sub L} and it is especially efficient for the accurate energy levels of the {gamma} rays by photoelectric effect. The double coincidence spectrometer has been conceived to get a good efficiency in coincidence: indeed, the sum of the solid angles used for the {beta} and {gamma} emission is rather little lower to 4{pi} steradians. To get this efficiency, one should have sacrificed a little the resolution that is lower to the one obtained with the solenoidal spectrometer for a same brightness. Each of the elements of the double spectrometer can also be adapted to the study of angular correlations {beta}{gamma} and e{sup -}{gamma}. In this use, it is superior to the thin magnetic lens used up to here. The double spectrometer also permits the survey of the coincidences e{sup -}e{sup -}, e{sup -}{beta} of a equivalent way to a double lens; it can also be consider some adaptation for the survey of the angular correlations e{sup -}e{sup -}, e{sup -}{beta}. Finally, we applied the methods by simple spectrometry and by coincidence spectrometry, to the study of the radiances of the following radioelements: {sup 76}As (26 h), {sup 122}Sb (2,8 j), {sup 124}Sb (60 j), {sup 125}Sb (2,7 years). (M.B.) [French] Les deux spectrometres qui ont ete realises permettent d'aborder un grand nombre de problemes de spectrometrie nucleaire. Ils possedent des champs d'application tres differents qui se completent. Le spectrometre solenoidal permet la determination des energies limites des spectres {beta} et de leur forme; il permet aussi la determination des coefficients de conversion interne et des rapports

  16. Study of radionuclides speciation with biological molecules of interest by spectrometric techniques; Etude de la speciation des radionucleides avec les molecules d'interet biologique par approche spectrometrique

    Energy Technology Data Exchange (ETDEWEB)

    Lourenco, V

    2007-07-15

    Mechanisms of complexation and accumulation of the radionuclides at the cellular and molecular level are complex and poorly known because the studies on these subjects are scarce. Within the framework of this thesis, we studied the interactions of these cations with biological molecules of interest. We chose to focus on an actinide: uranium (VI) as well as europium as an analogue of trivalent actinides. The selected biological molecules are the phyto-chelatins: their role is to protect cells against intrusions from nonessential heavy metals (thus toxic). These proteins are likely to be implied in the mechanisms of sequestration of radionuclides in living organisms. However, their structure is complex, this is why, in order to better include/understand their reactivity, we extended our studies to lower entities which constitute them (amino acid: glycine, glutamic acid and cysteine; polypeptides: glutathione reduced and oxidized forms). In particular, we determined solution speciation (stoichiometry, structure) as well as the complexing constants associated with the formation with these species. These studies were undertaken by Time Resolved Laser induced Fluorescence (TRLIF), Electro-Spray-Mass Spectrometry (ES-MS), Nuclear Magnetic Resonance (NMR), Fourier Transform Infra-Rouge spectroscopy (FTIR) and Extended X-ray Absorption Fine Structure Spectroscopy (EXAFS).The determination of the complexation constants enabled us to conclude that the complexing capacity of these molecules with respect to radionuclides was moderate (log{sub 10}K{sub 1} {<=} 3, pH 3 or 6), the formed species are mononuclear with only one ligand molecule (1:1). The interaction is performed via oxygenated (hard) groups. The direct complexation of europium with phyto-chelatins at acidic pH was studied jointly by TRLIF and ES-MS. The complexing capacity of these molecules is much higher than that of GSH from which they result. The interaction of europium with metallothioneins is, on the contrary

  17. Properties of superdeformed bands in the {sup 151}Tb nucleus studied with the EUROGAM French-British spectrometer; Proprietes des bandes superdeformees dans le noyau de {sup 151}Tb etudiees avec le spectrometre franco-britannique EUROGAM

    Energy Technology Data Exchange (ETDEWEB)

    Finck, Christian [Centre de Recherches Nucleaires de Strasbourg-Cronenbourg, 67 (France)

    1997-04-24

    The subject of this thesis is the study of superdeformation (SD) of the atomic nucleus. In the mass region A {approx_equal} 150 those nuclei have a quadrupole deformation of about 0.6. However, this value is an average and the microscopic structure reflected in the band configurations, affects this deformation. Determination of this value by electric quadrupole moment studies is particularly useful especially for the identical SD bands (SD bands belonging to neighbouring nuclei and having the same moment of inertia). Knowledge of the different quadrupole deformation should shed light on the competition between mass difference, spin alignment and deformation of the nucleus. The electric quadrupole moments are deduced from lifetime measurements of the SD states using the Doppler Shift Attenuation Method. Experimentally, one observes a variation in the electric quadrupole moments of the lowest SD states which suggests a gradual change of the nuclear deformation towards normal less deformed shapes. The deexcitation mechanism is poorly understood in the A {approx_equal} 150 mass region due to lack of experimental information: up to now, no transition connecting the second and the first potential well has been observed for these SD states. Experimental studies of deexcitation patterns of SD bands are therefore crucial to fix the decay-out mechanism. Experimental data on the {sup 151}Tb nucleus were collected via fusion-evaporation reaction, using the EUROGAM phase II array. (author) 121 refs., 61 figs., 22 tabs.

  18. Study of jet production in diffraction at HERA with the VFPS; Etude de la production de jets en diffraction a HERA, a l'aide du spectrometre a protons VFPS

    Energy Technology Data Exchange (ETDEWEB)

    Delvax, Julie

    2010-11-15

    In this thesis the experimental study of the process ep{yields}e{sup '}pX+n jets (N{>=}2) at {radical}(s)=319 GeV is described. Presented are distributions of E, y, p{sub t}, {theta}{sub j1}, {phi}{sub j1}, and {theta}{sub j1}-{theta}{sub j2}, {phi}{sub j1}-{phi}{sub j2}, and M{sub j1j2} for n=2, as well as the total cross section. (HSI)

  19. Study of dimuon spectrometer tracking chambers of the ALICE experiment at LHC; Etude des chambres de trajectoire du spectrometre dimuons de l'experience ALICE aupres du LHC

    Energy Technology Data Exchange (ETDEWEB)

    Kharmandarian, Liliane [Institut de Physique Nucleaire, CNRS - IN2P3, Universite Paris - Sud, 91406 Orsay Cedex (France)

    1999-12-16

    The ALICE (A Large Ion Collider Experiment) experiment will study ultrarelativistic heavy ion collisions at the Large Hadron Collider (LHC) in CERN as of 2005. An extensive R and D programme has been carried out on the dimuon spectrometer tracking chambers at the Nuclear Physics Institute in Orsay. Three multiwire proportional chamber prototypes with segmented cathodes, including a full-scale 1 m{sup 2} version, were constructed. In this thesis, the experimental tests are presented along with the simulations used to understand and optimize the detectors' performances. The prototypes were tested several times at the PS and SPS accelerators. The aims were to validate the choices made in terms of mechanical construction, geometrical parameters, gas mixture and read-out electronics. Analysis of the large amount of data collected has shown that the performances of this type of detector fulfill the required specifications. The results concerning the detectors' characteristics, spatial resolution efficiency, gain and homogeneity are given. Spatial resolutions of less than thirty microns were obtained. In parallel with the in-beam tests, several simulations have been developed in order to gain a better understanding of the detectors' response. They allowed, in particular, to define the segmentation of the cathode plane, to study the position reconstruction algorithm and to establish the future electronics specifications. (author)

  20. Development of a gas-ionization {beta}-spectrometer; Etude et realisation d'un spectrometre {beta} a ionisation gazeuse

    Energy Technology Data Exchange (ETDEWEB)

    Le Du, R [Commissariat a l' Energie Atomique, Bruyeres-le-Chatel (France). Centre d' Etudes

    1968-05-15

    We intend to develop in our laboratory a {beta}-spectrometer. This apparatus will have two main objectives: 1 - the determination of the nature and the degree of purity of certain {beta}-emitting radioactive substances; 2 - the study of an activity calibration process for {beta}-emitting radioactive sources. (author) [French] Nous nous proposons d'etudier et de realiser dans notre laboratoire un spectrometre {beta}. Cet appareil aura deux buts principaux: 1 - determiner la nature et le degre de purete de certains corps radioactifs emetteurs {beta}; 2 - permettre l'etude d'un procede d'etalonnage en activite de sources radioactives emetteurs {beta}. (auteur)

  1. A thermal analysis - mass spectrometric study of the reactions in the binary nitrate system UO2(NO3)2.6H2O-Ba(NO3)2

    International Nuclear Information System (INIS)

    Kalekar, B.B.; Rajagopalan, K.V.; Ravindran, P.V.

    2008-01-01

    Solid state reaction between uranyl nitrate hexahydrate and barium nitrate at elevated temperatures has been studied. Barium nitrate does not react directly with uranyl nitrate hexahydrate (UNH). The decomposition product of the latter, UO 3 , however, reacts with molten barium nitrate to form nitrato complexes which decompose to form barium uranates. The decomposition of the nitrato complex is often attended by a change of oxidation state of uranium. Uranyl-nitrate-rich compositions form uranates with uranium in oxidation state V, whereas barium-nitrate-rich compositions form uranates with uranium in oxidation state VI. The tendency for hydrolysis of uranyl nitrate hexahydrate at elevated temperatures is lowered in presence of barium nitrate and, unlike in the case of dehydration of pure UNH, uranyl nitrate dihydrate is formed as dehydration intermediate. (author)

  2. An overview on the study of quark gluon plasma with Alice dimuon spectrometer; Apercu sur l'etude du plasma de Quarks et de gluons a l'aide du spectrometre dimuons d'Alice

    Energy Technology Data Exchange (ETDEWEB)

    Espagnon, B

    2007-10-15

    The Alice experiment is one of the four main LHC (Large Hadron Collider) experiments. It is dedicated to the study of a new state of matter: the quark gluon plasma, where quarks and gluons are no longer confined within hadrons. In this document, the physics issues that led to the construction of Alice dimuon spectrometer, are described. Then, the research and development on the dimuon spectrometer is presented. The different absorbers are described and experimental tests used to determine their dimensions are presented. The dimuon trigger built using the RPC (Resistive Plate Chamber) streamer mode is then described along with the associated beam and cosmic tests and results. Finally, the tracking system is described in detail and more particularly all its electronics and the first station. The physics constraints on the expected performances of all these systems are clearly defined. (author)

  3. Processing of data issued from {gamma} spectrometer. Application to the study of decay schemes; Traitement des informations issues d'un spectrometre {gamma}. Application a l'etude de schemas de desintegration

    Energy Technology Data Exchange (ETDEWEB)

    Boulanger, J P; Legrand, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-07-01

    The main purpose of the following report is the study of a generation method of {gamma} spectra corresponding to any energy, from a library of some basic spectra. Then we point out how to establish the decay scheme of a radio-nuclide, in using an accurate analysis of full-energy peaks which appear in its complex spectrum, followed by a generation of plain spectra corresponding to the energies of the different transitions, and ending with a least-squares fitting procedure of the complex spectrum. The accuracy of the process is examined comparing the calculated spectra to the ones issued from two kinds of spectrometers (Na I(Tl) and Ge(Li)). The method is then applied to the study of {sup 134}Cs and {sup 95}Zr - {sup 95}Nb. (authors) [French] Le present rapport a pour principal objet l'etude d'une methode de generation de spectres {gamma} correspondant a n'importe quelle energie, a partir d'une bibliotheque de quelques spectres de reference. On montre ensuite comment on peut etablir le schema de desintegration d'un radionucleide, a l'aide d'une analyse precise des pics d'absorption totale apparaissant dans son spectre complexe, suivie d'une generation des spectres simples correspondant aux energies des diverses transitions, et en terminant par une decomposition du spectre complexe par la methode des moindres carres. On examine la validite du procede en comparant les spectres calcules a ceux obtenus avec deux types de detecteurs (scintillateurs et semi-conducteurs). On applique alors la methode a l'etude du {sup 134}Cs et du {sup 95}Zr - {sup 95}Nb. (auteurs)

  4. Mass spectrometric identification of isoforms of PR proteins in xylem sap of fungus-infected tomato

    NARCIS (Netherlands)

    Rep, Martijn; Dekker, Henk L.; Vossen, Jack H.; de Boer, Albert D.; Houterman, Petra M.; Speijer, Dave; Back, Jaap W.; de Koster, Chris G.; Cornelissen, Ben J. C.

    2002-01-01

    The protein content of tomato (Lycopersicon esculentum) xylem sap was found to change dramatically upon infection with the vascular wilt fungus Fusarium oxysporum. Peptide mass fingerprinting and mass spectrometric sequencing were used to identify the most abundant proteins appearing during

  5. Study of neutron hole states in 207206205Pb with the (3He,α) reaction at 110MeV. First tests in (d,t) reaction of the Orsay synchrocyclotron spectrometric line

    International Nuclear Information System (INIS)

    Guillot, J.

    1979-01-01

    Neutron hole states in the 207 Pb, 206 Pb, 205 Pb isotopes were studied up to 25 MeV excitation energy using the ( 3 He,α) reaction at 100MeV incident energy, with 100 keV energy resolution. Angular distributions for the low-lying levels and inner hole states have been analyzed with DWBA and spectroscopic factors extracted for 1 > 3 levels. Missing strengths for the first levels from 1i13/2 and 1h9/2 orbits are found in the bump located around 5MeV excitation energy. The fragmented bump observed around 8MeV excitation energy is attributed to 1h11/2 pick-up with 45% of the sum-rule limit. Finally, the structure extending up to 21 MeV excitation energy is attributed to 1g7/2+1g9/2 pick-up with 80% of the total strength. In 207 Pb, the four first isobaric analog states Tsub(>) = 45/2 are identifierd around 20MeV excitation energy. The second part of this work presents the first tests in (d,t) reaction at 108 MeV on 90 Zr and 208 Pb using the achromatic line of the Orsay synchrocyclotron [fr

  6. Thermodynamic properties over (Ni{sub 2}Te{sub 3}O{sub 8} + NiTe{sub 2}O{sub 5}) in the Ni-Te-O system. Transpiration thermogravimetric and Knudsen effusion mass spectrometric studies

    Energy Technology Data Exchange (ETDEWEB)

    Narasimhan, Tiruppatur Subramaniam Lakshmi; Nalini, Seshadreesan; Manikandan, Palraj; Trinadh, Vinjavarapu Venkata [Indira Gandhi Centre for Atomic Research, Kalpakkam (India). Fuel Chemistry Div.; Baba, Magapu Sai [Indira Gandhi Centre for Atomic Research, Kalpakkam (India). Resources Management Group

    2016-02-15

    Vaporisation studies over (Ni{sub 2}Te{sub 3}O{sub 8} + NiTe{sub 2}O{sub 5}) in the Ni-Te-O system were carried out by means of transpiration thermogravimetry (TTG) and Knudsen effusion mass spectrometry (KEMS) in the temperature ranges of 950 - 1 060 K and 850 - 950 K respectively. The transpiration measurements were performed for the first time. Comparison of total pressures obtained by TTG with that deduced using partial pressures of vaporising species from KEMS showed a good agreement providing reliable vapour pressures over this phase region. From vapour pressures, enthalpies of solid-gas and gas-phase equilibria and subsequently enthalpy and Gibbs free energies of formation of NiTe{sub 2}O{sub 5}(s) were derived. A thermochemical calculation was performed to assess the possibility of formation of the ternary NiTe{sub 2}O{sub 5}(s) phase on stainless steel clad of mixed-oxide fuelled fast breeder nuclear reactors.

  7. Trigger system study of the dimuon spectrometer in the ALICE experiment at CERN-LHC; Etude du systeme de declenchement du spectrometre dimuons de l'experience alice au Cern-LHC

    Energy Technology Data Exchange (ETDEWEB)

    Roig, O

    1999-12-01

    This work is a contribution to the study of nucleus-nucleus collisions at the LHC with ALICE. The aim of this experiment is to search for a new phase of matter, the quark-gluon plasma (QGP). The dimuon forward spectrometer should measure one of the most promising probes of the QGP, the production of heavy quark vector mesons (J/{psi}, {gamma}, {gamma}', {gamma}'') through their muonic decays. The dimuon trigger selects the interesting events performing a cut on the transverse momentum of the tracks. The trigger decision is taken by a dedicated electronics using RPC (''Resistive Plate Chambers'') detector information. We have made our own R and D program on the RPC detector with various beam tests. We show the performances obtained during these tests of a low resistivity RPC operating in streamer mode. The ALICE requirements concerning the rate capability, the cluster size and the time resolution are fulfilled. We have optimised the trigger with simulations which include a complete description of the read-out planes and the trigger logic (algorithm). In particular, a technique of clustering is proposed and validated. A method called ''Ds reduction'' is introduced in order to limit the effects of combinatorial background on the trigger rates. The efficiencies and the trigger rates are calculated for Pb-Pb, Ca-Ca, p-p collisions at the LHC. Other more sophisticated cuts, on the invariant mass for example, using again the RPC information have been simulated but have not shown significant improvements of the trigger rates. (author)

  8. Study of the electron-positron annihilation in the galactic center region with the Integral/SPI spectrometer; Etude de l'annihilation electron-positon dans la region du centre galactique avec le spectrometre INTEGRAL/SPI

    Energy Technology Data Exchange (ETDEWEB)

    Sizun, P

    2007-04-15

    A spectral feature was detected in 1970 in the gamma-ray emission from the central regions of the Milky Way, during balloon flight observations. Located near 511 keV, this feature was soon attributed to the gamma-ray line tracing the annihilation of electrons with their anti-particles, positrons. However, none of the multiple astrophysical scenarios contemplated to explain the production of positrons in the Galactic bulge has been able to reproduce the high injection rate deduced from the flux of the 511 keV line, close to 10{sup 43} positrons per second. Launched in 2002, the European gamma-ray satellite INTEGRAL was provided with a spectrometer, SPI, whose unprecedented imaging and spectral capabilities in this energy range enable us to further study the source of the 511 keV line detected in the Galactic centre region. Indeed, a better determination of the spatial extent of the source, the intrinsic width of the line and the fraction of positrons annihilating in-flight, directly or via the formation of ortho-Positronium atoms would improve our knowledge of both the annihilation medium and the initial source of positrons, and could allow us to discriminate between the various explanatory scenarios. The first part of this thesis deals with a key ingredient in the extraction of the annihilation spectrum: the optimization of the instrumental background model. New data screening and tracer selection procedures are presented. Classical multi-linear models are compared to neural and Bayesian networks. Finally, three years of observation are used to constrain the width of the source and derive its spectrum. The second part of the thesis focuses on one of the possible scenarios explaining the high positron injection rate deduced from the flux of the 511 keV line: the annihilation of light dark matter particles into electron-positron pairs. The various radiation mechanisms involved are modeled and confronted to observations in order to set an upper limit on the injection

  9. Review of procedures involving separation and preconcentration for the determination of cadmium using spectrometric techniques

    International Nuclear Information System (INIS)

    Ferreira, Sergio L.C.; Andrade, Jailson B. de; Korn, Maria das Gracas A.; Pereira, Madson de G.; Lemos, Valfredo A.; Santos, Walter N.L. dos; Rodrigues, Frederico de Medeiros; Souza, Anderson S.; Ferreira, Hadla S.; Silva, Erik G.P. da

    2007-01-01

    Spectrometric techniques for the analysis of trace cadmium have developed rapidly due to the increasing need for accurate measurements at extremely low levels of this element in diverse matrices. This review covers separation and preconcentration procedures, such as electrochemical deposition, precipitation, coprecipitation, solid phase extraction, liquid-liquid extraction (LLE) and cloud point extraction (CPE), and consider the features of the their application with several spectrometric techniques

  10. Energy Dispersive X-Ray Fluorescence Spectrometric Study of ...

    African Journals Online (AJOL)

    MBI

    2017-06-11

    Jun 11, 2017 ... Compositional Differences in Trace Elements in Dried Moringa oleifera ... Ti, Cu, Mo, Fe, Zn, Ni, Re, Eu and Pb using Energy Dispersive X-ray fluorescence ... Africa, Southeast Asia (Valdez-Solana et al., 2015). ... vegetable in many countries, including Nigeria .... of other elements in environmental samples.

  11. Spectrometric Study of the Nitrile-Ketenimines Tautomerism

    International Nuclear Information System (INIS)

    Cisneros, H.S.; Laurella, S.; Ruiz, D.L.; Ponzinibbio, A.; Allegretti, P.E.; Furlong, J.J.P.

    2011-01-01

    Mass spectrometry is used to evaluate the occurrence of the nitrile-ketenimines tautomerism. Mass spectra of two differently substituted nitriles, ethyl-4,4-dicyano-3-methyl-3-butenoate and diethyl-2-cyano-3-methyl-2-pentenodiate are examined looking for common mass spectral behaviors. Ion fragmentation assignments for specific tautomers allow to predict the presence of the corresponding structures. Additionally, the mass spectrum and nuclear magnetic resonance spectra of ethyl-4,4-dicyano-2,2-diethyl-3-methyl-3-butenoate and that of the corresponding amination product support the occurrence of the ketenimines tautomer in the equilibrium

  12. Spectrometric Study of the Nitrile-Ketenimine Tautomerism

    Directory of Open Access Journals (Sweden)

    Hebe Saraví Cisneros

    2009-01-01

    Full Text Available Mass spectrometry is used to evaluate the occurrence of the nitrile-ketenimine tautomerism. Mass spectra of two differently substituted nitriles, ethyl-4,4-dicyano-3-methyl-3-butenoate and diethyl-2-cyano-3-methyl-2-pentenodiate are examined looking for common mass spectral behaviors. Ion fragmentation assignments for specific tautomers allow to predict the presence of the corresponding structures. Additionally, the mass spectrum and nuclear magnetic resonance spectra of ethyl-4,4-dicyano-2,2-diethyl-3-methyl-3-butenoate and that of the corresponding amination product support the occurrence of the ketenimine tautomer in the equilibrium.

  13. Mass-spectrometric study of thermodynamics of molybdate potassium evaporation

    International Nuclear Information System (INIS)

    Kazenas, E.K.; Tsvetkov, Yu.V.; Samojlova, I.O.; Astakhova, G.K.; Petrov, A.A.

    2002-01-01

    One investigated into evaporation of potassium molybdate within 1170-1310 K temperature range using platinum effusion chambers. Evaporation of potassium molybdate within 1170-1310 K temperature range may be described as follows: K 2 MoO 4(s,l) = K 2 MoO 4(g) . Based on method of least squares one calculated equation of K 2 MoO 4(g) vapor pressure (pressure in millimeters of mercury column) dependence on temperature for 1200-1320 K range. One evaluated value of K 2 MoO 4(g) molecule atomization energy [ru

  14. Mass-spectrometric study of thermodynamics of lithium molybdate evaporation

    International Nuclear Information System (INIS)

    Kazanas, E.K.; Samojlova, O.I.; Astakhova, G.K.; Ovchinnikova, O.A.

    1999-01-01

    Evaporation of lithium molybdate in 1403-1504 K range was investigated by the method og high-temperature mass-spectrometry. It was established that Li 2 MoO 4 (g), Li 2 O(g), MoO 3 (g) molecules were present during Li 2 MoO 4 (l) evaporation in gaseous phase. Heat of formation of Li 2 MoO 4 (g) molecule was calculated. Heat of LiMoO 4 (sol) sublimation was determined with the use of thermodynamics law [ru

  15. In situ probing of cholesterol in astrocytes at the single-cell level using laser desorption ionization mass spectrometric imaging with colloidal silver.

    Science.gov (United States)

    Perdian, D C; Cha, Sangwon; Oh, Jisun; Sakaguchi, Donald S; Yeung, Edward S; Lee, Young Jin

    2010-04-30

    Mass spectrometric imaging has been utilized to localize individual astrocytes and to obtain cholesterol populations at the single-cell level in laser desorption ionization (LDI) with colloidal silver. The silver ion adduct of membrane-bound cholesterol was monitored to detect individual cells. Good correlation between mass spectrometric and optical images at different cell densities indicates the ability to perform single-cell studies of cholesterol abundance. The feasibility of quantification is confirmed by the agreement between the LDI-MS ion signals and the results from a traditional enzymatic fluorometric assay. We propose that this approach could be an effective tool to study chemical populations at the cellular level. Published in 2010 by John Wiley & Sons, Ltd.

  16. Contribution to the study of 14 MeV neutron scattering by {sup 12}C using a time-of-flight spectrometer (1963); Contribution a l'etude de la diffusion des neutrons de 14 MeV par {sup 12}C, a l'aide d'un spectrometre a temps de vol (1963)

    Energy Technology Data Exchange (ETDEWEB)

    Perrin, P [Commisariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1963-07-15

    Experimental measurements of 14 MeV fast neutrons scattering by {sup 12}C by time-flight spectrometer, with a 1.7 n. sec over-all resolution. The excitation of the 7.65 MeV level is observed. (author) [French] Etude experimentate de la diffusion par {sup 12}C des neutrons rapides de 14 MeV a l'aide d'un spectrometre de resolution totale de 17 n/s. Observation de l'excitation du niveau 0+ de 7,65 MeV. (auteur)

  17. Functional proteomics with new mass spectrometric and bioinformatics tools

    International Nuclear Information System (INIS)

    Kesners, P.W.A.

    2001-01-01

    A comprehensive range of mass spectrometric tools is required to investigate todays life science applications and a strong focus is on addressing the needs of functional proteomics. Application examples are given showing the streamlined process of protein identification from low femtomole amounts of digests. Sample preparation is achieved with a convertible robot for automated 2D gel picking, and MALDI target dispensing. MALDI-TOF or ESI-MS subsequent to enzymatic digestion. A choice of mass spectrometers including Q-q-TOF with multipass capability, MALDI-MS/MS with unsegmented PSD, Ion Trap and FT-MS are discussed for their respective strengths and applications. Bioinformatics software that allows both database work and novel peptide mass spectra interpretation is reviewed. The automated database searching uses either entire digest LC-MS n ESI Ion Trap data or MALDI MS and MS/MS spectra. It is shown how post translational modifications are interactively uncovered and de-novo sequencing of peptides is facilitated

  18. Determination of iodine to compliment mass spectrometric measurements

    International Nuclear Information System (INIS)

    Hohorst, F.A.

    1994-11-01

    The dose of iodine-129 to facility personnel and the general public as a result of past, present, and future activities at DOE sites is of continuing interest, WINCO received about 160 samples annually in a variety of natural matrices, including snow, milk, thyroid tissue, and sagebrush, in which iodine-129 is determined in order to evaluate this dose, Currently, total iodine and the isotopic ratio of iodine-127 to iodine-129 are determined by mass spectrometry. These two measurements determine the concentration of iodine-129 in each sample, These measurements require at least 16 h of mass spectrometer operator time for each sample. A variety of methods are available which concentrate and determine small quantities of iodine. Although useful, these approaches would increase both time and cost. The objective of this effort was to determine total iodine by an alternative method in order to decrease the load on mass spectrometry by 25 to 50%. The preparation of each sample for mass spectrometric analysis involves a common step--collection of iodide on an ion exchange bed. This was the focal point of the effort since the results would be applicable to all samples

  19. Mass Spectrometric C-14 Detection Techniques: Progress Report

    Science.gov (United States)

    Synal, H.

    2013-12-01

    Accelerator Mass Spectrometry (AMS) has been established as the best-suited radiocarbon detection technique. In the past years, significant progress with AMS instrumentation has been made resulting in a boom of new AMS facilities around the World. Today, carbon only AMS systems predominantly utilize 1+ charge state and molecule destruction in multiple ion gas collisions in stripper gas cell. This has made possible a significant simplification of the instruments, a reduction of ion energies and related to this less required space of the installations. However, state-of-the-art AMS instruments have still not reached a development stage where they can be regarded as table-top systems. In this respect, more development is needed to further advance the applicability of radiocarbon not only in the traditional fields of dating but also in biomedical research and new fields in Earth and environmental sciences. In a the proof-of-principle experiment the feasibility of radiocarbon detection over the entire range of dating applications was demonstrated using a pure mass spectrometer and ion energies below 50 keV. Now an experimental platform has been completed to test performance and to explore operation and measurement conditions of pure mass spectrometric radiocarbon detection. This contribution will overview the physical principles, which make this development possible and discuss key parameters of the instrumental design and performance of such an instrument.

  20. Surface acoustic wave nebulization facilitating lipid mass spectrometric analysis.

    Science.gov (United States)

    Yoon, Sung Hwan; Huang, Yue; Edgar, J Scott; Ting, Ying S; Heron, Scott R; Kao, Yuchieh; Li, Yanyan; Masselon, Christophe D; Ernst, Robert K; Goodlett, David R

    2012-08-07

    Surface acoustic wave nebulization (SAWN) is a novel method to transfer nonvolatile analytes directly from the aqueous phase to the gas phase for mass spectrometric analysis. The lower ion energetics of SAWN and its planar nature make it appealing for analytically challenging lipid samples. This challenge is a result of their amphipathic nature, labile nature, and tendency to form aggregates, which readily precipitate clogging capillaries used for electrospray ionization (ESI). Here, we report the use of SAWN to characterize the complex glycolipid, lipid A, which serves as the membrane anchor component of lipopolysaccharide (LPS) and has a pronounced tendency to clog nano-ESI capillaries. We also show that unlike ESI SAWN is capable of ionizing labile phospholipids without fragmentation. Lastly, we compare the ease of use of SAWN to the more conventional infusion-based ESI methods and demonstrate the ability to generate higher order tandem mass spectral data of lipid A for automated structure assignment using our previously reported hierarchical tandem mass spectrometry (HiTMS) algorithm. The ease of generating SAWN-MS(n) data combined with HiTMS interpretation offers the potential for high throughput lipid A structure analysis.

  1. Validation of a stability-indicating spectrometric method for the determination of sulfacetamide sodium in pure form and ophthalmic preparations

    Directory of Open Access Journals (Sweden)

    Sofia Ahmed

    2017-01-01

    Full Text Available Introduction: Sulfacetamide sodium is a widely used sulfonamide for ophthalmic infections. Objective: A number of analytical methods have been reported for the analysis of sulfacetamide but they lack the ability to determine both the active drug and its major degradation product, sulfanilamide, simultaneously in a sample. Materials and Methods: In the present study a simple, rapid and economical stability-indicating UV spectrometric method has been validated for the simultaneous assay of sulfacetamide sodium and sulfanilamide in pure form and in ophthalmic preparations. Results: The method has been found to be accurate (recovery 100.03 ±0.589% and precise (RSD 0.587% with detectable and quantifiable limits of 1.67×10–6 M (0.04 mg% and 5.07×10–6 M (0.13 mg%, respectively for the assay of pure sulfacetamide sodium. The method is also found to be accurate and precise to small changes in wavelength, pH and buffer concentration as well as to forced degradation. The study further includes the validation of the method for the assay of pure sulfanilamide in solution, which has been found to be accurate, precise and robust. Conclusion: The results indicate that the proposed two-component spectrometric method is stability-indicating and can be used for the simultaneous assay of both sulfacetamide sodium and sulfanilamide in synthetic mixtures and degraded solutions.

  2. Evaluation of radioactive environmental hazards in Area-3, Northern Palmyrides, Central Syria using airborne spectrometric gamma technique

    International Nuclear Information System (INIS)

    Asfahani, J.; Aissa, M.; Al-Hent, R.

    2016-01-01

    Airborne spectrometric gamma data are used in this paper to estimate the degree of radioactive hazard on humanity in Area-3, Northern Palmyrides, Central Syria. Exposure Rate (ER), Absorbed Dose Rate (ADR), Annual Effective Dose Rate (AEDR), and Heat Production (HP) of the eleven radiometric units included in the established lithological scored map in the study area have been computed to evaluate the radiation background influence in humans. The results obtained indicate that a human body in Area-3 is subjected to radiation hazards in the acceptable limits for long duration exposure. The highest radiogenetic heat production values in Area-3 correspond to the phosphatic locations characterized by relatively high values of uranium and thorium. - Highlights: • Degree of radioactive hazard has been estimated by using airborne spectrometric gamma data. • ER, ADR, AEDR, and HP of the eleven radiometric units have been computed. • Comparison of AEDR of Area-3 with the AEDR of Area-1. • Human body in Area-3 is subjected to radiation hazards in the acceptable limits for long duration exposure. • The highest heat production in Area-3 correspond to the phosphatic locations.

  3. Chromatographic, Spectroscopic and Mass Spectrometric Approaches for Exploring the Habitability of Mars in 2012 and Beyond with the Curiosity Rover

    Science.gov (United States)

    Mahaffy, Paul

    2012-01-01

    The Sample Analysis at Mars (SAM) suite of instruments on the Curiosity Rover of Mars Science Laboratory Mission is designed to provide chemical and isotopic analysis of organic and inorganic volatiles for both atmospheric and solid samples. The goals of the science investigation enabled by the gas chromatograph mass spectrometer and tunable laser spectrometer instruments of SAM are to work together with the other MSL investigations is to quantitatively assess habitability through a series of chemical and geological measurements. We describe the multi-column gas chromatograph system employed on SAM and the approach to extraction and analysis of organic compounds that might be preserved in ancient martian rocks.

  4. Validation of a UV Spectrometric Method for the Assay of Tolfenamic Acid in Organic Solvents

    Directory of Open Access Journals (Sweden)

    Sofia Ahmed

    2015-01-01

    Full Text Available The present study has been carried out to validate a UV spectrometric method for the assay of tolfenamic acid (TA in organic solvents. TA is insoluble in water; therefore, a total of thirteen commonly used organic solvents have been selected in which the drug is soluble. Fresh stock solutions of TA in each solvent in a concentration of 1 × 10−4 M (2.62 mg% were prepared for the assay. The method has been validated according to the guideline of International Conference on Harmonization and parameters like linearity, range, accuracy, precision, sensitivity, and robustness have been studied. Although the method was found to be efficient for the determination of TA in all solvents on the basis of statistical data 1-octanol, followed by ethanol and methanol, was found to be comparatively better than the other studied solvents. No change in the stock solution stability of TA has been observed in each solvent for 24 hours stored either at room (25±1°C or at refrigerated temperature (2–8°C. A shift in the absorption maxima has been observed for TA in various solvents indicating drug-solvent interactions. The studied method is simple, rapid, economical, accurate, and precise for the assay of TA in different organic solvents.

  5. A system design of gamma-ray spectrometric data processing for gold prospecting

    International Nuclear Information System (INIS)

    Yin Xueqin; Cheng Xuchu; Fang Lianxi; Huang Zuofeng.

    1992-01-01

    Based on different correlation between gamma-ray spectrometric data and gold grade in different types of gold deposits, it is necessary and possible to establish a mathematical model of gamma-ray spectrometric data processing for predicting specific gold deposits. A system design of gamma-ray spectrometric data processing for prospecting gold deposits has been worked out according to the mathematical method and procedure of data processing. The prediction effectiveness of commonly used multiple linear regression analysis is always not ideal but regression accuracy will be evidently increased after pre-processing of the calculated weight, deviation and favorability on gamma-ray spectrometric data. This system can establish more than ten models at the same time which enable users to have more choice. Tree structure and Chinese menu prompting are adopted in this system which can be utilized separately, sub-systems at different levels can be also individually operated. It can be transplanted to data processing of other similar geological deposit models (including non-gamma ray spectrometric data). The system is rapid, accurate, simple, convenient and flexible in use, more practical and easily popularized

  6. The use of car-borne gamma-ray spectrometric survey in a basin

    International Nuclear Information System (INIS)

    Liu Tengyao; Lu Shili; Luo Zongquan.

    1985-01-01

    This paper describes the geological results in a basin in the Inner Mongolia which were obtained by using our newly-developed and assembled car-borne gamma-ray spectrometric system. Combined with the work of regional geology and remote sensing, five relatively favourable uranium zones were located within the working area. The field procedures of car-borne gamma-ray spectrometry for less rigid regions is discussed. The gamma-ray spectrometric profiling is mainly used for regional reconnaissance. In the case of enhanced anomalious radioactivity the profiling with varying directions is adopted and the data are plotted on scale 1:50000 topographic map. It is suggested that the car-borne gamma-ray spectrometric system can be calibrated both by the pads specified for portable spectrometers and by testing site when the calibration facility for the car-borne gamma-ray spectrometric system is not available. The effect of rainfall on car-borne gamma-ray spectrometric survey and the simplified field qualitative determination of U-Ra disequilibrium are also briefly discussed

  7. Experimental characterization of the Clear-PEM scanner spectrometric performance

    Energy Technology Data Exchange (ETDEWEB)

    Bugalho, R; Carrico, B; Ferreira, C S; Frade, M; Ferreira, M; Moura, R; Ortigao, C; Pinheiro, J F; Rodrigues, P; Rolo, I; Silva, J C; Trindade, A; Varela, J [Laboratorio de Instrumentacao e Fisica Experimental de Particulas (LIP), Av. Elias Garcia 14-1, 1000-149 Lisboa (Portugal)], E-mail: frade@lip.pt

    2009-10-15

    In the framework of the Clear-PEM project for the construction of a high-resolution and high-specificity scanner for breast cancer imaging, a Positron Emission Mammography tomograph has been developed and installed at the Instituto Portugues de Oncologia do Porto hospital. The Clear-PEM scanner is mainly composed by two planar detector heads attached to a robotic arm, trigger/data acquisition electronics system and computing servers. The detector heads hold crystal matrices built from 2 x 2 x 20 mm{sup 3} LYSO:Ce crystals readout by Hamamatsu S8550 APD arrays. The APDs are optically coupled to both ends of the 6144 crystals in order to extract the DOI information for each detected event. Each one of 12288 APD's pixels is read and controlled by Application Specific Integrated Circuits water-cooled by an external cooling unit. The Clear-PEM frontend boards innovative design results in a unprecedented integration of the crystal matrices, APDs and ASICs, making Clear-PEM the PET scanner with the highest number of APD pixels ever integrated so far. In this paper, the scanner's main technical characteristics, calibration strategies and the first spectrometric performance evaluation in a clinical environment are presented. The first commissioning results show 99.7% active channels, which, after calibration, have inter-pixel and absolute gain distributions with dispersions of, respectively, 12.2% and 15.3%, demonstrating that despite the large number of channels, the system is uniform. The mean energy resolution at 511 keV is of 15.9%, with a 8.8% dispersion, and the mean C{sub DOI}{sup -1} is 5.9%/mm, with a 7.8% dispersion. The coincidence time resolution, at 511 keV, for a energy window between 400 and 600 keV, is 5.2 ns FWHM.

  8. Mass spectrometric behaviour of carboxylated polyethylene glycols and carboxylated octylphenol ethoxylates.

    Science.gov (United States)

    Frańska, Magdalena; Zgoła, Agnieszka; Rychłowska, Joanna; Szymański, Andrzej; Łukaszewski, Zenon; Frański, Rafał

    2003-01-01

    Mass spectrometric behaviour of mono- and di-carboxylated polyethylene glycols (PEGCs and CPEGCs) and carboxylated octylphenol ethoxylates (OPECs) are discussed. The tendency for ionisation (deprotonation, protonation and cationisation by alkali metal cations) of carboxylated PEGs was compared with that of non-carboxylated correspondents by using both secondary ion mass spectrometry (SIMS) and electrospray ionisation (ESI). The fragmentation of the PEGCs and CPEGCs is discussed and also compared with their neutral correspondents, PEGs. The B/E mass spectra were recorded, using secondary ion mass spectrometry as a method for generation, for deprotonated and protonated molecules and molecules cationised by alkali metal cations. The fragmentation behaviour of PEGs is found to be different from that of CPEGCs, The presence of carboxylic groups may be confirmed not only by the determination of molecular weights of the ethoxylates studied, but also on the basis of the fragment ions formed. The metastable decomposition of the [OPEC-H](-) ions proceed through the cleavage of the bond between the octylphenol moiety and the ethoxylene chain leading to the octylphenoxy anions. It permits determination of the mass of the hydrophobic moiety of the studied carboxylated alkylphenol ethoxylate. ESI mass spectra recorded in the negative ion mode were found to be more suitable for the determination of the average molecular weight of carboxylated ethoxylates than SI mass spectra.

  9. Mass Spectrometric Methodologies for Investigating the Metabolic Signatures of Parkinson's Disease: Current Progress and Future Perspectives.

    Science.gov (United States)

    Gill, Emily L; Koelmel, Jeremy P; Yost, Richard A; Okun, Michael S; Vedam-Mai, Vinata; Garrett, Timothy J

    2018-03-06

    Parkinson's disease (PD) is a neurodegenerative disorder resulting from the loss of dopaminergic neurons of the substantia nigra as well as degeneration of motor and nonmotor basal ganglia circuitries. Typically known for classical motor deficits (tremor, rigidity, bradykinesia), early stages of the disease are associated with a large nonmotor component (depression, anxiety, apathy, etc.). Currently, there are no definitive biomarkers of PD, and the measurement of dopamine metabolites does not allow for detection of prodromal PD nor does it aid in long-term monitoring of disease progression. Given that PD is increasingly recognized as complex and heterogeneous, involving several neurotransmitters and proteins, it is of importance that we advance interdisciplinary studies to further our knowledge of the molecular and cellular pathways that are affected in PD. This approach will possibly yield useful biomarkers for early diagnosis and may assist in the development of disease-modifying therapies. Here, we discuss preanalytical factors associated with metabolomics studies, summarize current mass spectrometric methodologies used to evaluate the metabolic signature of PD, and provide future perspectives of the rapidly developing field of MS in the context of PD.

  10. Significance of Airborne Gamma-ray spectrometric data of Umm bisilla Area, central Eastern Desert, Egypt

    Energy Technology Data Exchange (ETDEWEB)

    Rabie, S I [Nuclear materials authority, Maadi, Cairo, (Egypt)

    1995-10-01

    Umm bisilla area, located in the Central Eastern Desert of Egypt, consists mainly of basement rocks. The present investigation of the airborne spectrometric data is to define the meaningful anomalies from the raw data by applying the significance factor techniques, by calculating the significant radioactive provinces. Determination of the gross structural pattern and broad variations in composition of the crystalline basement, to define the relationships between the tectonic features of the area as interpreted from aeromagnetic data, with the significant anomalies revealed from spectrometric data was carried out through the application of different magnetic techniques. Five significant uraniferous zones were detected associated with Umm Bisilla granite, amphibolite, and grey granite. The intersection of the structural lineaments interpreted from aeromagnetic data illustrated good correlation with the significant uranium anomalous zones interpreted from spectrometric data, and indicated that the concentration is structurally. 15 figs.

  11. Low-activity spectrometric gamma-ray logging technique for delineation of coal/rock interfaces in dry blast holes

    International Nuclear Information System (INIS)

    Asfahani, J.; Borsaru, M.

    2007-01-01

    A low-activity spectrometric gamma-ray logging technique is proposed in this paper as a sensitive tool for the delineation of coal/rock interfaces in dry blast holes. The advantages and superiority of this technique over traditional micro-density non-spectrometric gamma-ray tools are demonstrated

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

    International Nuclear Information System (INIS)

    Doyle, Adriana; Saavedra, Alvaro; Tristão, Maria Luiza B.; Mendes, Luiz A.N.; Aucélio, Ricardo Q.

    2013-01-01

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

  13. Stability and linearity control of spectrometric channels of the Cherenkov counters using controllable units

    International Nuclear Information System (INIS)

    Kollar, D.; Kollarova, L.; Khorvat, P.

    1976-01-01

    A system is elaborated to control stability and linearity of the Cherenkov counter spectrometric channels in an experiment on a magnetic monopole search. Linearity of a light characteristic of a photoelectric multiplier is checked with the help of the calibrated light-strikings of light emitting diodes with flare intensity adjusted by controlling generator voltage across the mercury body. A program algorithm is presented for checking stability and linearity of the Cherenkov counter spectrometric channels which helps to consider the fatigue effects of the photoelectric multiplier resulting from the considerable loads

  14. Mass Spectrometric Characteristics of Prenylated Indole Derivatives from Marine-Derived Penicillium sp. NH-SL.

    Science.gov (United States)

    Ding, Hui; Ding, Wanjing; Ma, Zhongjun

    2017-03-22

    Two prenylated indole alkaloids were isolated from the ethyl acetate extracts of a marine-derived fungus Penicillium sp. NH-SL and one of them exhibited potent cytotoxic activity against mouse hepa 1c1c7 cells. In order to detect other bioactive analogs, we used liquid chromatogram tandem mass spectrometry (LC-MS/MS) to analyze the mass spectrometric characteristics of the isolated compounds as well as the crude extracts. As a result, three other analogs were detected, and their structures were deduced according to the similar fragmentation patterns. This is the first systematic report on the mass spectrometric characteristics of prenylated indole derivatives.

  15. Spectrometric properties of crystals for low-energy x-ray diagnostics

    International Nuclear Information System (INIS)

    Barrus, D.m.; Blake, R.L.; Felthauser, H.; Fenimore, E.E.

    1981-01-01

    Quantitative diagnostics of fusion and astrophysical plasmas require knowledge of crystal spectrometric properties. To provide more reliable and versatile diagnostics of plasma conditions, increasingly accurate knowledge of crystal spectrometric properties is becoming necessary. A summary is presented of the following accurately measured parameters for the crystals KAP, RbAP, TlAP, NH 4 AP, NaAP, ADP, and EDDT: the interplanar spacing of atoms; the angle correction for normal and anomalous dispersion that is required for application of the Bragg formula; the thermal expansion coefficient near room temperature for commonly used planes; and the integrated coefficient of reflection

  16. Determination of deuterium in metal by vacuum fusion-mass spectrometric method

    International Nuclear Information System (INIS)

    Wada, Yukio; Akiyama, Shigeo; Ochiai, Ken-ichi; Asakura, Toshiro; Tsutsumi, Ken-ichi

    1976-01-01

    A specimen of deuterium-enriched Zircaloy was prepared to study a method for the determination of deuterium in metal. The measuring apparatus consists of vacuum fusion section (10 -5 -10 -4 Torr), gas extracting and collecting section, the section of introducing both standard D 2 and HD gases into a gas holder, and mass spectrometric analysis section. The deuterium in Zircaloy can be extracted by 100% for 5 min. at 1600 0 C. The main components of the extracted gas are H 2 , D 2 , HD, CO, H 2 O and N 2 . Deuterium is determined by the calculation from the determinations of D 2 and HD. The amounts of D 2 and HD gases in the specimen were obtained from the calibration curve prepared and the spectrum intensity of D 2 + and HD + resulted from specimen analysis. As a result of the analysis of D 2 -enriched Zircaloy, it has been found that the precision of the determination is within the coefficient variation of about 3% for the extracted D 2 gas amount of 10 -3 -10 -2 ml (STP), including the deuterium segregation in the specimen, and the determination limit was 1 x 10 -5 ml (STP). (Kobatake, H.)

  17. A Chemical Eight Group Separation Method for Routine Use in Gamma Spectrometric Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Samsahl, K

    1961-04-15

    A method for the separation of chemical elements in 8 groups suitable for gamma spectrometric analysis has been developed. One group of elements is separated by distillation during dissolution of the sample. The other groups are obtained by means of short ion exchange columns coupled in series An anion exchange column saturated with chloride ions separates chloride complexes, peroxides and other anions from a 3-n HCl + 0.3 % H{sub 2}O{sub 2} sample solution. Some of the chloride complexes are eluted with 0.1-n HCl + 0.3 % H{sub 2}O{sub 2} and subsequently adsorbed as cations on a cation exchange column in hydrogen form. A few eluted elements which do not form cations in this case are found in the effluent. Elements passing the anion exchange column in chloride form without adsorption are separated from a H{sub 2}O solution as citrate complexes, hydroxides, cations and hexametaphosphate complexes. This is done by coupling in series two anion exchange columns subsequently in citrate and hydroxide form and followed by a cation exchanger in sodium form. A mixed bed column ends the series. The behaviour in the separation series of most elements forming gamma emitting isotopes with half lives exceeding 10 minutes on irradiation with thermal neutrons has been studied. The method has been used, routinely for one year.

  18. Sequence-specific capture of protein-DNA complexes for mass spectrometric protein identification.

    Directory of Open Access Journals (Sweden)

    Cheng-Hsien Wu

    Full Text Available The regulation of gene transcription is fundamental to the existence of complex multicellular organisms such as humans. Although it is widely recognized that much of gene regulation is controlled by gene-specific protein-DNA interactions, there presently exists little in the way of tools to identify proteins that interact with the genome at locations of interest. We have developed a novel strategy to address this problem, which we refer to as GENECAPP, for Global ExoNuclease-based Enrichment of Chromatin-Associated Proteins for Proteomics. In this approach, formaldehyde cross-linking is employed to covalently link DNA to its associated proteins; subsequent fragmentation of the DNA, followed by exonuclease digestion, produces a single-stranded region of the DNA that enables sequence-specific hybridization capture of the protein-DNA complex on a solid support. Mass spectrometric (MS analysis of the captured proteins is then used for their identification and/or quantification. We show here the development and optimization of GENECAPP for an in vitro model system, comprised of the murine insulin-like growth factor-binding protein 1 (IGFBP1 promoter region and FoxO1, a member of the forkhead rhabdomyosarcoma (FoxO subfamily of transcription factors, which binds specifically to the IGFBP1 promoter. This novel strategy provides a powerful tool for studies of protein-DNA and protein-protein interactions.

  19. Resolution of a protein sequence ambiguity by X-ray crystallographic and mass spectrometric methods

    International Nuclear Information System (INIS)

    Keefe, L.J.; Lattman, E.E.; Wolkow, C.; Woods, A.; Chevrier, M.; Cotter, R.J.

    1992-01-01

    Ambiguities in amino acid sequences are a potential problem in X-ray crystallographic studies of proteins. Amino acid side chains often cannot be reliably identified from the electron density. Many protein crystal structures that are now being solved are simple variants of a known wild-type structure. Thus, cloning artifacts or other untoward events can readily lead to cases in which the proposed sequence is not correct. An example is presented showing that mass spectrometry provides an excellent tool for analyzing suspected errors. The X-ray crystal structure of an insertion mutant of Staphylococcal nuclease has been solved to 1.67 A resolution and refined to a crystallographic R value of 0.170. A single residue has been inserted in the C-terminal α helix. The inserted amino acid was believed to be an alanine residue, but the final electron density maps strongly indicated that a glycine had been inserted instead. To confirm the observations from the X-ray data, matrix-assisted laser desorption mass spectrometry was employed to verify the glycine insertion. This mass spectrometric technique has sufficient mass accuracy to detect the methyl group that distinguishes glycine from alanine and can be extended to the more common situation in which crystallographic measurements suggest a problem with the sequence, but cannot pinpoint its location or nature. (orig.)

  20. Resolution of a protein sequence ambiguity by X-ray crystallographic and mass spectrometric methods

    Energy Technology Data Exchange (ETDEWEB)

    Keefe, L.J.; Lattman, E.E. (Dept. of Biophysics and Biophysical Chemistry, Johns Hopkins Univ. School of Medicine, Baltimore, MD (United States)); Wolkow, C.; Woods, A.; Chevrier, M.; Cotter, R.J. (Middle Atlantic Mass Spectrometry Lab., Johns Hopkins Univ. School of Medicine, Baltimore, MD (United States))

    1992-04-01

    Ambiguities in amino acid sequences are a potential problem in X-ray crystallographic studies of proteins. Amino acid side chains often cannot be reliably identified from the electron density. Many protein crystal structures that are now being solved are simple variants of a known wild-type structure. Thus, cloning artifacts or other untoward events can readily lead to cases in which the proposed sequence is not correct. An example is presented showing that mass spectrometry provides an excellent tool for analyzing suspected errors. The X-ray crystal structure of an insertion mutant of Staphylococcal nuclease has been solved to 1.67 A resolution and refined to a crystallographic R value of 0.170. A single residue has been inserted in the C-terminal {alpha} helix. The inserted amino acid was believed to be an alanine residue, but the final electron density maps strongly indicated that a glycine had been inserted instead. To confirm the observations from the X-ray data, matrix-assisted laser desorption mass spectrometry was employed to verify the glycine insertion. This mass spectrometric technique has sufficient mass accuracy to detect the methyl group that distinguishes glycine from alanine and can be extended to the more common situation in which crystallographic measurements suggest a problem with the sequence, but cannot pinpoint its location or nature. (orig.).

  1. Mass spectrometric investigation of neutral and charged constituents in saturated vapor over PrI3

    International Nuclear Information System (INIS)

    Motalov, V.B.; Vorobiev, D.E.; Kudin, L.S.; Markus, T.

    2009-01-01

    The Knudsen effusion mass spectrometric technique was used to study vapor species over praseodymium triiodide. The monomer, PrI 3 , and dimer, Pr 2 I 6 , molecules and the negative ions, PrI 4 - and Pr 2 I 7 - , were observed in saturated vapor in the temperature range from 856 K to 1048 K. The partial vapor pressures of neutral constituents were determined and the enthalpies of sublimation obtained using the second and the third laws of thermodynamics (Δ s H deg. (298.15 K) = 291 ± 4 kJ mol -1 for PrI 3 , and Δ s H deg. (298.15 K) = 400 ± 30 kJ mol -1 for Pr 2 I 6 ). The equilibrium constants for various ion molecular reactions were measured and the enthalpies of reactions obtained. The enthalpies of formation, Δ f H deg. (298.15 K) kJ mol -1 , of gaseous molecules and ions were calculated and are as follows: -374 ± 6 (PrI 3 ), -929 ± 30 (Pr 2 I 6 ), -867 ± 30 (PrI 4 - ), -1432 ± 50 (Pr 2 I 7 - )

  2. Spectroscopic and Spectrometric Methods Used for the Screening of Certain Herbal Food Supplements Suspected of Adulteration.

    Science.gov (United States)

    Mateescu, Cristina; Popescu, Anca Mihaela; Radu, Gabriel Lucian; Onisei, Tatiana; Raducanu, Adina Elena

    2017-06-01

    Purpose: This study was carried out in order to find a reliable method for the fast detection of adulterated herbal food supplements with sexual enhancement claims. As some herbal products are advertised as "all natural", their "efficiency" is often increased by addition of active pharmaceutical ingredients such as PDE-5 inhibitors, which can be a real health threat for the consumer. Methodes: Adulterants, potentially present in 50 herbal food supplements with sexual improvement claims, were detected using 2 spectroscopic methods - Raman and Fourier Transform Infrared - known for reliability, reproductibility, and an easy sample preparation. GC-MS technique was used to confirm the potential adulterants spectra. Results: About 22% (11 out of 50 samples) of herbal food supplements with sexual enhancement claims analyzed by spectroscopic and spectrometric methods proved to be "enriched" with active pharmaceutical compounds such as: sildenafil and two of its analogues, tadalafil and phenolphthalein. The occurence of phenolphthalein could be the reason for the non-relevant results obtained by FTIR method in some samples. 91% of the adulterated herbal food supplements were originating from China. Conclusion: The results of this screening highlighted the necessity for an accurate analysis of all alleged herbal aphrodisiacs on the Romanian market. This is a first such a screening analysis carried out on herbal food supplements with sexual enhancement claims.

  3. The interlaboratory experiment IDA-72 on mass spectrometric isotope dilution analysis. Vol. 1

    International Nuclear Information System (INIS)

    Beyrich, W.; Drosselmeyer, E.

    1975-07-01

    Within the framework of the Safeguards Project of the Federal Republic of Germany at the Nuclear Research Center Karlsruhe an analytical intercomparison program was carried out in cooperation with 22 laboratories of 13 countries or international organizations. The main objective was the acquisition of basic data on the errors involved in the mass spectrometric isotope dilution analysis if it is applied to the determination of uranium and plutonium in diluted active feed solutions of reprocessing plants in routine operation. The results were evaluated by statistical methods mainly in regard to the calculation of the estimates of the variances for the different error components contributing to the total error of this analytical technique. Furthermore, the performance of two new methods for sample conditioning suggested by the International Atomic Energy Agency, Vienna, and the European Institute for Transuranium Elements (EURATOM), Karlsruhe, was successfully tested. The results of some investigations on the stability of diluted high active feed solutions and on comparison analysis by X-ray fluorescence spectrometry are also included. Data on the analytical efforts (manhours) invested in this study are reported as well as general experiences made in the organization and performance of an experiment on such an extended international level. (orig.) [de

  4. Characterization of plant polysaccharides from Dendrobium officinale by multiple chromatographic and mass spectrometric techniques.

    Science.gov (United States)

    Ma, Huiying; Zhang, Keke; Jiang, Qing; Dai, Diya; Li, Hongli; Bi, Wentao; Chen, David Da Yong

    2018-04-27

    Plant polysaccharides have numerous medicinal functions. Due to the differences in their origins, regions of production, and cultivation conditions, the quality and the functions of polysaccharides can vary significantly. They are macromolecules with large molecular weight (MW) and complex structure, and pose great challenge for the analytical technology used. Taking Dendrobium officinale (DO) from various origins and locations as model samples. In this investigation, mechanochemical extraction method was used to successfully extract polysaccharides from DO using water as solvent, the process is simple, fast (40 s) and with high yield. The MWs of the intact saccharides from calibration curve and light scattering measurement were determined and compared after separation with size exclusion chromatography (SEC). The large polysaccharide was acid hydrolyzed to oligosaccharides and the products were efficiently separated and identified using liquid chromatography coupled to a high resolution tandem mass spectrometry (LC-MS 2 ). Obvious differences were observed among LC-MS 2 chromatograms of digested products, and the chemical structures for the products were proposed based on accurate mass values. More importantly, isomeric digested carbohydrate compounds were explored and characterized. All the chromatographic and mass spectrometric results in this study provided a multi-dimensional characterization, fingerprint analysis, and molecular structure level assessment of plant polysaccharides. Copyright © 2018 Elsevier B.V. All rights reserved.

  5. Tropical Journal of Pharmaceutical Research - Vol 14, No 1 (2015)

    African Journals Online (AJOL)

    Larvicidal Activity of Essential Oil Derived from Illicium henryi Diels (Illiciaceae) ... on the Stability of Soybean Oil · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT ... Gas Chromatographic-Mass Spectrometric Analysis of Essential Oil of ...

  6. Mass spectrometric protein characterization in proteome analysis using GELoader tip micro-columns packed with various chromatographic material

    International Nuclear Information System (INIS)

    Larsen, M.R.

    2001-01-01

    In the early 90'ies mass spectrometry (MS) was introduced as a tool for identifying proteins in protein sequence databases. Since then it has become an integrated tool in protein characterization and is today routinely used to identify proteins separated by gel electrophoresis. A two-tiered mass spectrometric protein identification strategy has recently been proposed. In the first strategy peptide mass maps obtained from the protein of interest are compared with theoretically derived peptide mass maps from proteins in protein sequence databases. If the protein cannot be identified by this strategy, tandem mass spectrometric sequencing is used to generate enough sequence data to identify the protein in protein sequence databases or expressed sequence tag (EST) databases. However, the above strategies primarily identify a protein relatively to the DNA sequence, in which no information about e.g. post-translational modifications (PTMs) is stored. PTMs are known to modify the function, location, solubility and activity of proteins in the cell, and they are therefore very important for understanding living cells. More than 200 different PTMs are known, of which glycosylation, phosphorylation and proteolytic processing are the most common ones. Mass spectrometric analysis of PTMs on gel-separated proteins requires a higher amount of protein than for identification only. In addition, higher sequence coverage from the peptide mass maps or pre-purification of the modified peptides prior to MS analysis, is necessary for detection of putative modified peptides. In this study a multi-tiered strategy, in which GELoader tip micro-columns packed with increasingly more hydrophobic chromatographic material are used in combination with mass spectrometry, is described. The ultimate aim was to gain increased sequence coverage from peptide mixtures derived from gel-separated proteins, in order to locate modified peptides. Graphite powder is described as an alternative to traditional

  7. Gamma-spectrometric analysis of river sediments collected around phosphate fertilizer industries

    International Nuclear Information System (INIS)

    Gallardo, M.C.; Garcia-Leon, M.; Mundi, M.; Respaldiza, M.A.

    1993-01-01

    Gamma-ray spectrometric analysis has been carried out on sediments collected in an estuarine system formed by two major rivers in southern Spain. The results show clearly that important amounts of natural radioactivity are accumulating on the bed of both rivers. This radioactivity appears to originate from effluent from several phoshate fertilizer factories adjacent to the estuary. (author)

  8. Spectrometric storage device in VME standard; Spektrometricheskoe zapominayushchee ustrojstvo v standarte VME

    Energy Technology Data Exchange (ETDEWEB)

    Rezaev, V E

    1996-12-31

    Paper describes module of histogram Memory Module designed to implement hardware way of accumulation of spectrometric data in systems based on VME standard equipment. Application of HMM module enables to increase throughput of the system for data acquisition and processing as in this case VME bus trunk is not occupied and may be used to control experiment course. 2 figs.

  9. Retrospective detection of exposure to organophosphorus anti-cholinesterases: Mass spectrometric analysis of phosphylated human butyrylcholinesterase

    NARCIS (Netherlands)

    Fidder, A.; Hulst, A.G.; Noort, D.; Ruiter, R. de; Schans, M.J. van der; Benschop, H.P.; Langenberg, J.P.

    2002-01-01

    In this paper a novel and general procedure is presented for detection of organophosphate-inhibited human butyrylcholinesterase (HuBuChE), which is based on electrospray tandem mass spectrometric analysis of phosphylated nonapeptides obtained after pepsin digestion of the enzyme. The utility of this

  10. Radiochemical separation and alpha-spectrometric determination of Americium in different matrixes

    International Nuclear Information System (INIS)

    Radenkovic, M.; Joksic, J.; Paligoric, D.

    2009-01-01

    A method of separation and alpha-spectrometric determination of americium, developed in VINCA Institute of Nuclear Sciences is described in the paper. The procedure is convenient to be used for 241 Am determination in environmental matrixes as well as samples of human origin if a very small concentrations are expected, using 243 Am as a tracer for radiochemical yield recovery. (author) [sr

  11. The AS-76 interlaboratory experiment on the alpha spectrometric determination of Pu-238. Pt. 1

    International Nuclear Information System (INIS)

    Beyrich, W.; Spannagel, G.

    1979-12-01

    In cooperation with 26 laboratories of 11 countries or international organizations, the Safeguards Project of the Karlsruhe Nuclear Research Center carried out the interlaboratory program AS-76. It focused on the alpha-spectrometric determination of the Pu-238 isotope. The performance of the program as well as the results obtained are described. (orig.) 891 HP/orig. 892 MKO [de

  12. Mass spectrometric identification of isocyanate-induced modifications of keratins in human skin

    NARCIS (Netherlands)

    Hulst, A.G.; Verstappen, D.R.W.; Riet-van Oeveren, D. van der; Vermeulen, N.P.E.; Noort, D.

    2015-01-01

    In the current paper we show that exposure of human callus to isocyanates leads to covalent modifications within keratin proteins. Mass spectrometric analyses of pronase digests of keratin isolated from exposed callus show that both mono- and di-adducts (for di-isocyanates) are predominantly formed

  13. A novel mass spectrometric strategy "BEMAP" reveals Extensive O-linked protein glycosylation in Enterotoxigenic Escherichia coli

    DEFF Research Database (Denmark)

    Boysen, Anders; Palmisano, Giuseppe; Krogh, Thøger Jensen

    2016-01-01

    The attachment of sugars to proteins via side-chain oxygen atoms (O-linked glycosylation) is seen in all three domains of life. However, a lack of widely-applicable analytical tools has restricted the study of this process, particularly in bacteria. In E. coli, only four O-linked glycoproteins have...... previously been characterized. Here we present a glycoproteomics technique, termed BEMAP, which is based on the beta-elimination of O-linked glycans followed by Michael-addition of a phosphonic acid derivative, and subsequent titanium dioxide enrichment. This strategy allows site-specific mass......-spectrometric identification of proteins with O-linked glycan modifications in a complex biological sample. Using BEMAP we identified cell surface-associated and membrane vesicle glycoproteins from Enterotoxigenic E. coli (ETEC) and non-pathogenic E. coli K-12. We identified 618 glycosylated Serine and Threonine residues...

  14. Analysis of hairy root culture of Rauvolfia serpentina using direct analysis in real time mass spectrometric technique.

    Science.gov (United States)

    Madhusudanan, K P; Banerjee, Suchitra; Khanuja, Suman P S; Chattopadhyay, Sunil K

    2008-06-01

    The applicability of a new mass spectrometric technique, DART (direct analysis in real time) has been studied in the analysis of the hairy root culture of Rauvolfia serpentina. The intact hairy roots were analyzed by holding them in the gap between the DART source and the mass spectrometer for measurements. Two nitrogen-containing compounds, vomilenine and reserpine, were characterized from the analysis of the hairy roots almost instantaneously. The confirmation of the structures of the identified compounds was made through their accurate molecular formula determinations. This is the first report of the application of DART technique for the characterization of compounds that are expressed in the hairy root cultures of Rauvolfia serpentina. Moreover, this also constitutes the first report of expression of reserpine in the hairy root culture of Rauvolfia serpentina. Copyright (c) 2008 John Wiley & Sons, Ltd.

  15. Rational utilisation of a spectrometer detector for leaks; Utilisation rationnelle d'un spectrometre detecteur de fuites

    Energy Technology Data Exchange (ETDEWEB)

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

    1954-07-01

    In this following article, we expose the general problem of the leakage in a vacuum installation. We consider the principles of the detection in general and study especially the conditions of detection by an helium spectrometer. We deduce practical conclusions as for the branching of this last and to its application in the most current cases. (author) [French] Dans l'article qui suit, nous exposons le probleme general des fuites dans une installation a vide. Nous y envisageons les principes de la detection en general et etudions particulierement les conditions de detection par spectrometre a helium. Noue tirons des conclusions pratiques quant au branchement de ce dernier et a son application dans les cas les plus courants. (auteur)

  16. Vitamin D-metabolites from human plasma and mass spectrometric analysis by fast heavy ion induced desorption

    Energy Technology Data Exchange (ETDEWEB)

    Fohlman, J; Peterson, P A [Uppsala Univ. (Sweden). Dept. of Cell Research; Kamensky, I; Hakansson, P; Sundqvist, B [Tandemacceleratorlaboratoriet, Uppsala (Sweden)

    1982-07-01

    D-vitamin metabolites have been isolated from human serum employing chromatographic techniques. The serum carrier protein for vitamin D (DBP) was first isolated by immunosorbent chromatography. Lipid ligands associated with DBP were then extracted with hexane and separated by high pressure liquid chromatography (HPLC). Detection of vitamin D metabolites by their absorbance of ultraviolet light is not sufficiently sensitive to monitor all vitamin D derivatives from a few millilitres of serum. Therefore, further analyses are necessary to quantitative these compounds. We have begun to develop a mass spectrometric method to achieve a reliable, quantitative procedure. As a first step towards this goal a number of pure samples of vitamin D compounds have been studied in a time-of-flight mass spectrometer based on fast heavy ion induced desorption. All vitamin D compounds examined could be detected and identified by their molecular ion and fragment spectra.

  17. Vitamin D-metabolites from human plasma and mass spectrometric analysis by fast heavy ion induced desorption

    International Nuclear Information System (INIS)

    Fohlman, J.; Peterson, P.A.

    1982-01-01

    D-vitamin metabolites have been isolated from human serum employing chromatographic techniques. The serum carrier protein for vitamin D (DBP) was first isolated by immunosorbent chromatography. Lipid ligands associated with DBP were then extracted with hexane and separated by high pressure liquid chromatography (HPLC). Detection of vitamin D metabolites by their absorbance of ultraviolet light is not sufficiently sensitive to monitor all vitamin D derivatives from a few millilitres of serum. Therefore, further analyses are necessary to quantitative these compounds. We have begun to develop a mass spectrometric method to achieve a reliable, quantitative procedure. As a first step towards this goal a number of pure samples of vitamin D compounds have been studied in a time-of-flight mass spectrometer based on fast heavy ion induced desorption. All vitamin D compounds examined could be detected and identified by their molecular ion and fragment spectra. (orig.)

  18. Mass spectrometric detection of proteins in non-aqueous media : the case of prion proteins in biodiesel

    Energy Technology Data Exchange (ETDEWEB)

    Douma, M.D.; Kerr, G.M.; Brown, R.S.; Keller, B.O.; Oleschuk, R.D. [Queen' s Univ., Kingston, ON (Canada). Dept. of Chemistry

    2008-08-15

    This paper presented a filtration method for detecting protein traces in non-aqueous media. The extraction technique used a mixture of acetonitrile, non-ionic detergent and water along with filter disks with embedded C{sub 8}-modified silica particles to capture the proteins from non-aqueous samples. The extraction process was then followed by an elution of the protein from the filter disk and direct mass spectrometric detection and tryptic digestion with peptide mapping and MS/MS fragmentation of protein-specific peptides. The method was used to detect prion proteins in spiked biodiesel samples. A tryptic peptide with the sequence YGQGSPGGNR was used for unambiguous identification. Results of the study showed that the method is suitable for the large-scale testing of protein impurities in tallow-based biodiesel production processes. 33 refs., 6 figs.

  19. Spectrometric and Voltammetric Analysis of Urease – Nickel Nanoelectrode as an Electrochemical Sensor

    Directory of Open Access Journals (Sweden)

    Rene Kizek

    2007-07-01

    Full Text Available Urease is the enzyme catalyzing the hydrolysis of urea into carbon dioxide andammonia. This enzyme is substrate-specific, which means that the enzyme catalyzes thehydrolysis of urea only. This feature is a basic diagnostic criterion used in thedetermination of many bacteria species. Most of the methods utilized for detection ofurease are based on analysis of its enzyme activity – the hydrolysis of urea. The aim of thiswork was to detect urease indirectly by spectrometric method and directly by voltammetricmethods. As spectrometric method we used is called indophenol assay. The sensitivity ofdetection itself is not sufficient to analyse the samples without pre-concentration steps.Therefore we utilized adsorptive transfer stripping technique coupled with differential pulse voltammetry to detect urease. The influence of accumulation time, pH of supporting electrolyte and concentration of urease on the enzyme peak height was investigated. Under the optimized experimental conditions (0.2 M acetate buffer pH 4.6 and accumulation time of 120 s the detection limit of urease evaluated as 3 S/N was 200 ng/ml. The activity of urease enzyme depends on the presence of nickel. Thus the influence of nickel(II ions on electrochemical response of the enzyme was studied. Based on the results obtained the interaction of nickel(II ions and urease can be determined using electrochemical methods. Therefore we prepared Ni nanoelectrodes to measure urease. The Ni nanoelectrodes was analysed after the template dissolution by scanning electron microscopy. The results shown vertically aligned Ni nanopillars almost covered the electrode surface, whereas the defect places are minor and insignificant in comparison with total electrode surface. We were able to not only detect urease itself but also to distinguish its native and denatured form.

  20. Mass spectrometric identification of proteins that interact through specific domains of the poly(A) binding protein.

    Science.gov (United States)

    Richardson, Roy; Denis, Clyde L; Zhang, Chongxu; Nielsen, Maria E O; Chiang, Yueh-Chin; Kierkegaard, Morten; Wang, Xin; Lee, Darren J; Andersen, Jens S; Yao, Gang

    2012-09-01

    Poly(A) binding protein (PAB1) is involved in a number of RNA metabolic functions in eukaryotic cells and correspondingly is suggested to associate with a number of proteins. We have used mass spectrometric analysis to identify 55 non-ribosomal proteins that specifically interact with PAB1 from Saccharomyces cerevisiae. Because many of these factors may associate only indirectly with PAB1 by being components of the PAB1-mRNP structure, we additionally conducted mass spectrometric analyses on seven metabolically defined PAB1 deletion derivatives to delimit the interactions between these proteins and PAB1. These latter analyses identified 13 proteins whose associations with PAB1 were reduced by deleting one or another of PAB1's defined domains. Included in this list of 13 proteins were the translation initiation factors eIF4G1 and eIF4G2, translation termination factor eRF3, and PBP2, all of whose previously known direct interactions with specific PAB1 domains were either confirmed, delimited, or extended. The remaining nine proteins that interacted through a specific PAB1 domain were CBF5, SLF1, UPF1, CBC1, SSD1, NOP77, yGR250c, NAB6, and GBP2. In further study, UPF1, involved in nonsense-mediated decay, was confirmed to interact with PAB1 through the RRM1 domain. We additionally established that while the RRM1 domain of PAB1 was required for UPF1-induced acceleration of deadenylation during nonsense-mediated decay, it was not required for the more critical step of acceleration of mRNA decapping. These results begin to identify the proteins most likely to interact with PAB1 and the domains of PAB1 through which these contacts are made.

  1. Application and evaluation of the mass spectrometric isotope dilution technique in the determination of rare earths in geological materials

    International Nuclear Information System (INIS)

    Moraes, N.M.P. de.

    1988-01-01

    Establishment of the experimental procedures employed in the rare earth element determination of geological samples by mass spectrometric isotope dilution analysis is discussed in the present work. The procedures involve preparation and calibration of the isotope tracers isotope dilution, dissolution in a teflon pressure vessel, chemical separation and isotope analysis using a fully automated Micromass VG ISOTOPES model 354 thermal ionization mass spectrometer. For the initial chemical separation of total rare earths the cationic resin was employed and HC1 and HNO 3 acids as eluents. In the second step rare earths elements were separated into individual (La, Ce and Nd) and subgroups (Sm-Eu-Gd, Yb-Er-Dy) fractions using the same cationic resin and α-HIBA as eluent. Nine elements La, Ce, Nd, Sm, Eu, Gd, Dy, Er and Yb are determined by this method in the ''United States Geological Survey'' (USGS) standard samples GSP-1, AGV-1 and G-2, with an overall precision of +- 1 to 2% and an accuracy of 5%. The concentration of rare earth element determined in the standard sample PCC-1 showed that the total analytical blanks are in submicrogram levels. The concentration of rare earth elements in the same USGS standard samples were also determined by Instrumental neutron activation analysis, neutron activation analysis with chemical separation before irradiation and inductively coupled argon plasma spectroscopy. The chemical procedures employed for these methods are the same as that used for mass spectrometric isotope dilution. Based on the results obtained, each method was evaluated pointing out their merits and defects. The study clearly showed that the chemical procedure employed for all these techniques was satisfactory. (author) [pt

  2. Mass spectrometric analysis of electrophoretically separated allergens and proteases in grass pollen diffusates

    Directory of Open Access Journals (Sweden)

    Geczy Carolyn L

    2003-09-01

    Full Text Available Abstract Background Pollens are important triggers for allergic asthma and seasonal rhinitis, and proteases released by major allergenic pollens can injure airway epithelial cells in vitro. Disruption of mucosal epithelial integrity by proteases released by inhaled pollens could promote allergic sensitisation. Methods Pollen diffusates from Kentucky blue grass (Poa pratensis, rye grass (Lolium perenne and Bermuda grass (Cynodon dactylon were assessed for peptidase activity using a fluorogenic substrate, as well as by gelatin zymography. Following one- or two-dimensional gel electrophoresis, Coomassie-stained individual bands/spots were excised, subjected to tryptic digestion and analysed by mass spectrometry, either MALDI reflectron TOF or microcapillary liquid chromatography MS-MS. Database searches were used to identify allergens and other plant proteins in pollen diffusates. Results All pollen diffusates tested exhibited peptidase activity. Gelatin zymography revealed high Mr proteolytic activity at ~ 95,000 in all diffusates and additional proteolytic bands in rye and Bermuda grass diffusates, which appeared to be serine proteases on the basis of inhibition studies. A proteolytic band at Mr ~ 35,000 in Bermuda grass diffusate, which corresponded to an intense band detected by Western blotting using a monoclonal antibody to the timothy grass (Phleum pratense group 1 allergen Phl p 1, was identified by mass spectrometric analysis as the group 1 allergen Cyn d 1. Two-dimensional analysis similarly demonstrated proteolytic activity corresponding to protein spots identified as Cyn d 1. Conclusion One- and two-dimensional electrophoretic separation, combined with analysis by mass spectrometry, is useful for rapid determination of the identities of pollen proteins. A component of the proteolytic activity in Bermuda grass diffusate is likely to be related to the allergen Cyn d 1.

  3. Mature forms of the major seed storage albumins in sunflower: A mass spectrometric approach.

    Science.gov (United States)

    Franke, Bastian; Colgrave, Michelle L; Mylne, Joshua S; Rosengren, K Johan

    2016-09-16

    Seed storage albumins are abundant, water-soluble proteins that are degraded to provide critical nutrients for the germinating seedling. It has been established that the sunflower albumins encoded by SEED STORAGE ALBUMIN 2 (SESA2), SESA20 and SESA3 are the major components of the albumin-rich fraction of the common sunflower Helianthus annuus. To determine the structure of sunflowers most important albumins we performed a detailed chromatographic and mass spectrometric characterization to assess what post-translational processing they receive prior to deposition in the protein storage vacuole. We found that SESA2 and SESA20 each encode two albumins. The first of the two SESA2 albumins (SESA2-1) exists as a monomer of 116 or 117 residues, differing by a threonine at the C-terminus. The second of the two SESA2 albumins (SESA2-2) is a monomer of 128 residues. SESA20 encodes the albumin SESA20-2, which is a 127-residue monomer, whereas SESA20-1 was not abundant enough to be structurally described. SESA3, which has been partly characterized previously, was found in several forms with methylation of its asparagine residues. In contrast to other dicot albumins, which are generally matured into a heterodimer, all the dominant mature sunflower albumins SESA2, SESA20-2, SESA3 and its post-translationally modified analogue SESA3-a are monomeric. Sunflower plants have been bred to thrive in various climate zones making them favored crops to meet the growing worldwide demand by humans for protein. The abundance of seed storage proteins makes them an important source of protein for animal and human nutrition. This study explores the structures of the dominant sunflower napin-type seed storage albumins to understand what structures evolution has favored in the most abundant proteins in sunflower seed. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

  4. Determination of 21 trace impurities in UO2 with tributyl phosphate chromatographic separation-USN-inductively coupled/atomic emission spectrometric

    International Nuclear Information System (INIS)

    Hou Lieqi; Wang Shuan; Li Jie

    1996-03-01

    A method of tributyl phosphate chromatographic separation-USN-inductively coupled/atomic emission spectrometric was selected. And the parameters, interference of acid concentrations, interference of coexisting elements, selecting of flow for carrier gas, solution temperature were studied. When the sampling amount is 250 mg, the determination range for Al, Ag, Ba, Ca, Cd, Co, Cr, Cu, Fe, In, Li, Mg, Mn, Mo, Ni, Pb, Sn, Ti, V, Y and Zn are 0.2∼100 ng· -1 , recovery are 94%∼110%. The RSD (n 8) are 0.8%∼6.2%. (3 refs., 4 tabs.)

  5. Gamma-spectrometric surveys in differentiated granites. I: a review of the method and of the geochemical behavior of K, Th and U

    International Nuclear Information System (INIS)

    Ulbrich, Horstpeter Herberto Gustavo Jose; Ulbrich, Mabel Norma Costas; Guimaraes, Gilson Burigo

    2009-01-01

    This contribution is part of a research project on the Neo proterozoic Cunhaporanga Granitic Complex (CGC), cropping out in the Ponta Grossa Arch (Parana state, SE Brazil). An initial study used the gamma-spectrometric data of the Serra do Mar Sul Aero geophysical Project, performed during the 70's for CPRM. Later, terrestrial gamma-spectrometric surveys focused on the study of the differentiated Joaquim Murtinho Granite (JMG) in the NW corner of CGC, and the Serra do Carambei Granite, to the SW. In this paper, the results obtained for JMG are presented in two parts. The first deals with methodology and the presentation of several gamma-spectrometric 'color-scale' maps, indicating that results obtained in granites depend strongly on a climatic factor, given the mobility of K during weathering in subtropical climates with strong rainfalls, also favoring a greater mobility of U. Minerals that are U and Th hosts, documented in granites, are reviewed, together with the weathering processes that control the mobility of K, U and Th in soils. Strong K signals in granitic areas submitted to these climates document the presence of fresh rock and/or effects of hydrothermal alteration, while weak or nil signals are evidence of strong leaching of K during weathering. U and Th will be retained in the residual soils, in part leading to their selective enrichment, also coupled with soil migration to lower topographic levels by colluvial transport. The larger solubility of U (as uranyl ion) allows its liberation under oxidizing conditions, and its migration, limited by the possibility of absorption in newly formed mineral and organic soil phases. Th should be retained almost totally in resistant phases and, when liberated in solution, will mostly be fixed in organic and inorganic soil substances. (author)

  6. High-efficient method for spectrometric data real time processing with increased resolution of a measuring channel

    International Nuclear Information System (INIS)

    Ashkinaze, S.I.; Voronov, V.A.; Nechaev, Yu.I.

    1988-01-01

    Solution of reduction problem as a mean to increase spectrometric tract resolution when it is realized using the digit-by-digit modified method and special strategy, significantly reducing the time of processing, is considered. The results presented confirm that the complex measurement tract plus microcomputer is equivalent to the use of the tract with a higher resolution, and the use of the digit-by-digit modified method permits to process spectrometric information in real time scale

  7. New FORTRAN computer programs to acquire and process isotopic mass-spectrometric data

    International Nuclear Information System (INIS)

    Smith, D.H.

    1982-08-01

    The computer programs described in New Computer Programs to Acquire and Process Isotopic Mass Spectrometric Data have been revised. This report describes in some detail the operation of these programs, which acquire and process isotopic mass spectrometric data. Both functional and overall design aspects are addressed. The three basic program units - file manipulation, data acquisition, and data processing - are discussed in turn. Step-by-step instructions are included where appropriate, and each subsection is described in enough detail to give a clear picture of its function. Organization of file structure, which is central to the entire concept, is extensively discussed with the help of numerous tables. Appendices contain flow charts and outline file structure to help a programmer unfamiliar with the programs to alter them with a minimum of lost time

  8. Standard test methods for chemical, mass spectrometric, and spectrochemical analysis of nuclear-grade boron carbide

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2004-01-01

    1.1 These test methods cover procedures for the chemical, mass spectrometric, and spectrochemical analysis of nuclear-grade boron carbide powder and pellets to determine compliance with specifications. 1.2 The analytical procedures appear in the following order: Sections Total Carbon by Combustion and Gravimetry 7-17 Total Boron by Titrimetry 18-28 Isotopic Composition by Mass Spectrometry 29-38 Chloride and Fluoride Separation by Pyrohydrolysis 39-45 Chloride by Constant-Current Coulometry 46-54 Fluoride by Ion-Selective Electrode 55-63 Water by Constant-Voltage Coulometry 64-72 Impurities by Spectrochemical Analysis 73-81 Soluble Boron by Titrimetry 82-95 Soluble Carbon by a Manometric Measurement 96-105 Metallic Impurities by a Direct Reader Spectrometric Method 106-114

  9. The interlaboratory experiment IDA-72 on mass spectrometric isotope dilution analysis. Vol. 2

    International Nuclear Information System (INIS)

    Beyrich, W.; Drosselmeyer, E.

    1975-07-01

    Volume II of the report on the IDA-72 experiment contains papers written by different authors on a number of special topics connected with the preparation, performance and evaluation of the interlaboratory test. In detail the sampling procedures for active samples of the reprocessing plant and the preparation of inactive reference and spike solution from standard material are described as well as new methods of sample conditioning by evaporation. An extra chapter is devoted to the chemical sample treatment as a preparation for mass spectrometric analysis of the U and Pu content of the solutions. Special topics are also methods for mass discrimination corrections, α-spectrometer measurements as a supplement for the determination of Pu-238 and the comparison of concentration determinations by mass spectrometric isotope dilution analysis with those performed by X-ray fluorescence spectrometry. The last part of this volume contains papers connected with the computerized statistical evaluation of the high number of data. (orig.) [de

  10. [Determination of trace cobalt in human urine by graphite furnace atomic absorption spectrometr].

    Science.gov (United States)

    Zhong, L X; Ding, B M; Jiang, D; Liu, D Y; Yu, B; Zhu, B L; Ding, L

    2016-05-20

    To establish a method to determine cobalt in human urine by graphite furnace atomic absorption spectrometry. Urine with 2% nitric acid diluted two-fold, to quantify the curve, graphite furnace atomic absorption spectrometric detection. Co was linear within 2.5~40.0 ng/ml with r>0.999. Spike experiment showed that Co received good recovery rate, which was 90.8%~94.8%. Intra-assay precisions were 3.2%~5.1% for Co, inter-assay precisions were 4.4%~5.2% for Co. The method by using graphite furnace atomic absorption spectrometr to determine urine Co was fast, accurate and with low matrix effect. It could meet the requirement in GBZ/T 210.5-2008.

  11. The fast gamma spectrometric method of the Am-241 determination in Chernobyl restricted zone soils

    International Nuclear Information System (INIS)

    Gleisberg, B.; Lukachina, V.V.; Kirsenko, V.N.; Tepikin, V.E.; Rajevsky, V.S.; Libman, V.A.; Stoljarevsky, I.P.; Isajev, A.G.

    1997-01-01

    The known methods of the 241 Am contents determination in environmental objects, as a rule, is based on ion-chromatographic or extraction separation techniques. This approach reflects widespread opinion, that only the α-spectrometric analysis termination is suitable to ensure necessary sensitivity of the overall method of 241 Am actively determination. Really, the minimal detectable activity for such methods is about 0.05 Bq/kg (considering that Am is usually concentrated during separation procedure). However, because of α-spectrometry does not permit to separate the α-peaks of the 241 Am, and 238 Pu, but also in view of high requests to the α-spectrometric specimen purity, the multistage and laborious chemical procedures to separate 241 Am from plutonium radionuclides and other elements (with a thorough control of each separation stage) are needed

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

    International Nuclear Information System (INIS)

    Boisde, G.; Perez, J.J.

    1988-01-01

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

  13. Gamma-spectrometric examination of hot particles emitted during the Chernobyl accident

    International Nuclear Information System (INIS)

    Balashazy, I.; Szabadine-Szende, G.; Loerinc, M.; Zombori, P.

    1987-05-01

    Ge(Li) gamma-spectrometric examination of hot particles prepared from air filtered dust of Budapest air after the Chernobyl accident is presented. The method of separating hot particles is described and their concentration in the air is determined. The radioactive isotope composition of hot particles is discussed and compared with that of dust samples. Finally, the inhalation probability and radiation burden of hot particles are evaluated. (author)

  14. A method for exploring the distribution of radioelements at depth using gamma-ray spectrometric data

    International Nuclear Information System (INIS)

    Li Qingyang

    1997-01-01

    Based on the inherent relation between radioelements and terrestrial heat flow, theoretically shows the possibility of exploring the distribution of radioelements at depth using gamma-ray spectrometric data, and a data-processing and synthesizing method has been adopted to deduce the calculation formula. The practical application in the uranium mineralized area No. 2801 in Yunnan Province proves that this method is of practical value, and it has been successfully applied to the data processing and good results have been obtained

  15. Sensitive emission spectrometric method for the analysis of airborne particulate matter

    International Nuclear Information System (INIS)

    Sugimae, A.

    1975-01-01

    A rapid and sensitive emission spectrometric method for the routine analysis of airborne particulate matter collected on the glass fiber filter is reported. The method is a powder--dc arc technique involving no chemical pre-enrichment procedures. The elements--Ag, BA: Be, Bi, Cd, Co, Cr, Cu, Fe, Ga, La, Mn, Ni, Pb, Sn, V, Y, Yb, and Zn--were determined. (U.S.)

  16. Uncertainty assessment in gamma spectrometric measurements of plutonium isotope ratios and age

    Energy Technology Data Exchange (ETDEWEB)

    Ramebaeck, H., E-mail: henrik.ramebeck@foi.se [Swedish Defence Research Agency, FOI, Division of CBRN Defence and Security, SE-901 82 Umea (Sweden); Chalmers University of Technology, Department of Chemical and Biological Engineering, Nuclear Chemistry, SE-412 96 Goeteborg (Sweden); Nygren, U.; Tovedal, A. [Swedish Defence Research Agency, FOI, Division of CBRN Defence and Security, SE-901 82 Umea (Sweden); Ekberg, C.; Skarnemark, G. [Chalmers University of Technology, Department of Chemical and Biological Engineering, Nuclear Chemistry, SE-412 96 Goeteborg (Sweden)

    2012-09-15

    A method for the assessment of the combined uncertainty in gamma spectrometric measurements of plutonium composition and age was evaluated. Two materials were measured. Isotope dilution inductively coupled plasma sector field mass spectrometry (ID-ICP-SFMS) was used as a reference method for comparing the results obtained with the gamma spectrometric method for one of the materials. For this material (weapons grade plutonium) the measurement results were in agreement between the two methods for all measurands. Moreover, the combined uncertainty in all isotope ratios considered in this material (R{sub Pu238/Pu239}, R{sub Pu240/Pu239}, R{sub Pu241/Pu239}, and R{sub Am241/Pu241} for age determination) were limited by counting statistics. However, the combined uncertainty for the other material (fuel grade plutonium) were limited by the response fit, which shows that the uncertainty in the response function is important to include in the combined measurement uncertainty of gamma spectrometric measurements of plutonium.

  17. Maintenance of stability in γ spectrometric system of low active and environmental samples - a practical experience

    International Nuclear Information System (INIS)

    Ravishankar, R.; Bandyopadhyay, T.; Sarkar, P.K.

    2011-01-01

    Particle Accelerators are becoming part of the society with more and more medical and Industrial types are added every year in addition to research type of accelerators. The outflow of materials to the public domain from such accelerator facilities need to checked carefully and must be released after ensuring the activities of such materials should not exceed the regulatory limits. Health Physics Unit, VECC is involved in analyzing food product samples, seized samples which are suspected to contain Uranium etc and other environmental samples in addition to analyzing radioactive materials evolved from Operational Health Physics work. Most of these analyses involve γ Spectrometric Systems of high efficiency and high resolution types. The efficacy of the analysis and results depends on various parameters of the spectrometric system. The electrical noise from the power supply system and other noises picked up, even in the range of a few milli volts range, have been found to affect the stability of the system. These effects may not be present initially during installation but may creep in due course due to various reasons including weather conditions, wear and tear etc. Unless these problems are attended in regular intervals, the stability of the spectrometric systems and hence the results of analysis of the low active and environmental samples, will not be satisfactory. The work describes the practical problems faced by Health Physics Unit, the methods employed in identifying the problems, the necessary remedial measures taken, the final outcome in the stability and the procedures framed in order to avoid in future. (author)

  18. Spectrometric aerial survey as a new tool for geological survey and mining prospecting

    International Nuclear Information System (INIS)

    Cambon, R.

    1997-01-01

    Airborne survey for radioactive minerals started around 1945. The limited sensitivity of the tools used, the difficulties found for the topographic and training effect corrections, made difficult the evaluation of the results. The technical progresses realized in the recent past years in electronic and computer sciences allowed to overcome these difficulties and gave to the method all its potentialities. With the aerial spectrometric survey, a new step was made, because this method can be used for other topics than radioactive prospection such as geological survey and mining prospection for metallic and industrial minerals. The spectrometric method is based on the possibility to measure photopeak energies (gamma radiation) emitted by radioactive minerals and discriminate between them those emitted by U238, TI 208 and K40 respectively daughter products of uranium, thorium and potassium. For airborne survey, one consider that measuring instruments will allow to pick-up 80% of the radioactive emission concerning the first 15 to 30 centimetres of ground (1 metre maximum). The use of this method for geological and mineral exploration is based on the assumption that different rock types or ore bearing rock types are composed of certain amounts of rock forming minerals which comprise specific quantities of radioactive elements such as potassium, uranium and thorium (cf: Gabelman 77). To be able to evaluate the results of the spectrometric survey it will be necessary to know roughly the behaviour of the different radioactive elements through a complete geological cycle. (author)

  19. Mirion--a software package for automatic processing of mass spectrometric images.

    Science.gov (United States)

    Paschke, C; Leisner, A; Hester, A; Maass, K; Guenther, S; Bouschen, W; Spengler, B

    2013-08-01

    Mass spectrometric imaging (MSI) techniques are of growing interest for the Life Sciences. In recent years, the development of new instruments employing ion sources that are tailored for spatial scanning allowed the acquisition of large data sets. A subsequent data processing, however, is still a bottleneck in the analytical process, as a manual data interpretation is impossible within a reasonable time frame. The transformation of mass spectrometric data into spatial distribution images of detected compounds turned out to be the most appropriate method to visualize the results of such scans, as humans are able to interpret images faster and easier than plain numbers. Image generation, thus, is a time-consuming and complex yet very efficient task. The free software package "Mirion," presented in this paper, allows the handling and analysis of data sets acquired by mass spectrometry imaging. Mirion can be used for image processing of MSI data obtained from many different sources, as it uses the HUPO-PSI-based standard data format imzML, which is implemented in the proprietary software of most of the mass spectrometer companies. Different graphical representations of the recorded data are available. Furthermore, automatic calculation and overlay of mass spectrometric images promotes direct comparison of different analytes for data evaluation. The program also includes tools for image processing and image analysis.

  20. Car-borne multichannel gamma-ray spectrometric system model CZD-6

    International Nuclear Information System (INIS)

    Lu Shili; Zhai Yugui; Ma Yanfang; Jiao Cangwen; Zhang Biao

    1998-01-01

    The car-borne multichannel gamma-ray spectrometric system Mode CZD-6 is composed of a HDY-256 of portable multichannel gamma-ray spectrometer developed by the Beijing Research Institute of Uranium Geology and a large volume scintillation detector. the position for each measurement point is determined by the GPS instrument. Its latitude and longitude, as well as measured 256 channels of γ-spectrometric data are collected by a notebook computer, which can show the 256 channels of spectra for each point during measuring processes. The complete system can be loaded in a field car. This system has been used to environmental radioactive monitoring after calibration by airborne radiometric models in Shijiazhuang, Hebei province. A lot of data confirm that the system works stably and reliably, and is a fast and advanced approach for environmental γ-spectrometric monitoring. It can be used not only to determination of contents of natural radioactive elements in environments, but also to monitoring nuclear pollution and emergency treatment in nuclear accidents significantly

  1. The leakage problem in vacuum system. Realization of a mass spectrometer detecting leaks; Le probleme des fuites en technique du vide. Realisation d'un spectrometre de masse detecteur de fuite

    Energy Technology Data Exchange (ETDEWEB)

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

    1954-11-15

    In the first part of this paper we consider the problem of leaks in vacuum systems, and their detection. We consider in particular the method of detection by means of a helium spectrometer. The second part deals with the experimental set p. The analyser and the ion source have been studied in great detail, and we have also discussed the technological and mechanical aspects of the apparatus and its performances. (author) [French] Dans la premiere partie de ce travail, nous traitons le probleme des fuites en technique du vide et leur detection en general. La methode de detection par spectrometre a helium y est envisagee plus particulierement. La deuxieme partie de l'article est consacree a la realisation du spectrometre. Le tube analyseur et la source d'ions y sont etudies en detail. Nous exposons de meme les conceptions technologiques et mecaniques de l'appareil ainsi que ses performances. (auteur)

  2. Deuterium oxide as a tool for the study of amino acid metabolism

    International Nuclear Information System (INIS)

    Mitra, R.; Burton, J.; Varner, J.E.

    1976-01-01

    We have used deuterium oxide in nontoxic concentrations to study, in intact seedlings, the biosynthesis of amino acids. The extent and pattern of deuteration, as determined by a gas--liquid chromatograph--mass spectrometer system, permits conclusions about the biosynthesis of individual amino acids and also about their exposure to transaminases and other enzymes that might introduce deuterium into specific positions of the amino acid by exchange. This method could be used to study amino acid biogenesis in any organism that can tolerate 20 to 40 percent deuterium oxide for a period of a few hours to a few days

  3. Rapid in situ gamma spectrometric determination of fallout radioactivity in the environment. Progress report

    International Nuclear Information System (INIS)

    Zombori, Peter

    1995-01-01

    layers. Though fresh fallout is often assumed to be distributed completely on the ground surface recent studies revealed that a certain penetration of the radioactivity into the soil can occur already in the first instance. The improper estimation of the distribution parameter can result in a deviation of the determined activity concentration from the true value by a factor of 2 or more. This way the reliability of the method is limited due to the lack of information on the depth profile of the activity concentration. The main objective of our study is to find a method (or more, if possible) to estimate the penetration character of the fallout radioactivity by using only spectral information obtained by the in situ spectrometric measurement thus avoiding the need for a long and tiresome sampling and sample analysis procedure

  4. Exploring Blueberry Aroma Complexity by Chromatographic and Direct-Injection Spectrometric Techniques

    Science.gov (United States)

    Farneti, Brian; Khomenko, Iuliia; Grisenti, Marcella; Ajelli, Matteo; Betta, Emanuela; Algarra, Alberto Alarcon; Cappellin, Luca; Aprea, Eugenio; Gasperi, Flavia; Biasioli, Franco; Giongo, Lara

    2017-01-01

    , for the most aldehydes, alcohols, terpenoids, and esters that can be used as putative biomarkers to rapidly evaluate the blueberry aroma variations related to ripening and/or senescence as well as to genetic background differences. Moreover, the obtained results demonstrated the complementarity between chromatographic and direct-injection mass spectrometric techniques to study the blueberry aroma. PMID:28491071

  5. Exploring Blueberry Aroma Complexity by Chromatographic and Direct-Injection Spectrometric Techniques

    Directory of Open Access Journals (Sweden)

    Brian Farneti

    2017-04-01

    pull of VOCs, for the most aldehydes, alcohols, terpenoids, and esters that can be used as putative biomarkers to rapidly evaluate the blueberry aroma variations related to ripening and/or senescence as well as to genetic background differences. Moreover, the obtained results demonstrated the complementarity between chromatographic and direct-injection mass spectrometric techniques to study the blueberry aroma.

  6. Exploring Blueberry Aroma Complexity by Chromatographic and Direct-Injection Spectrometric Techniques.

    Science.gov (United States)

    Farneti, Brian; Khomenko, Iuliia; Grisenti, Marcella; Ajelli, Matteo; Betta, Emanuela; Algarra, Alberto Alarcon; Cappellin, Luca; Aprea, Eugenio; Gasperi, Flavia; Biasioli, Franco; Giongo, Lara

    2017-01-01

    , and esters that can be used as putative biomarkers to rapidly evaluate the blueberry aroma variations related to ripening and/or senescence as well as to genetic background differences. Moreover, the obtained results demonstrated the complementarity between chromatographic and direct-injection mass spectrometric techniques to study the blueberry aroma.

  7. Recognition of favorable zones for uranium and thorium accumulation, at Um Ara-Um Shilman granitic pluton, south eastern desert, Egypt, using airborne spectrometric and magnetic data

    International Nuclear Information System (INIS)

    Elkattan, E.M.

    1995-01-01

    The objective is aimed at identifying significant U and Th anomalies, the amount of re-mobilization of U and Th, the structural framework of the granite pluton and the distribution of spectrometric anomalies. The study revealed that the granite pluton could be represented as a single radio-lithologic unit excluding abnormal measurements exceeding Xban + 2S. It also revealed the existence of eight strong spectrometric anomalies. Observed values of eU correlate well with eTh, r=0.72 while the correlation between eU/eTh and eU is lacking, r=0.190. Meanwhile, there is a negative correlation between eU/eTh and eTh,r= -0.335. This deficiency in correlation suggests a limited or zero remobilization of uranium, which was partly governed by magmatic processes. Most of the radioactive anomalies were found within or near the major contact faults which may act as channels for mineralized fluids from the subsurface. These fluids possess increased concentrations of U and/or Th which could exist in appropriate chemical and/or structural traps. The U and Th anomalies were found to be associated with the northern and southern parts of the granite pluton respectively. The difference between the northern and southern parts of the granite pluton may be attributed to differences in radioelement content, the effect of partial and/or complete digestion of older rocks, or to different levels of erosion. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Karadjova, Irina B. [Faculty of Chemistry, University of Sofia, 1 James Bourchier Blvd., Sofia 1164 (Bulgaria); Lampugnani, Leonardo [C.N.R. Istituto per i processi chimico-fisici, Area della Ricerca di Pisa, Via Moruzzi 1, 56124 Pisa (Italy)]. E-mail: lampugnani@ipcf.cnr.it; Onor, Massimo [C.N.R. Istituto per i processi chimico-fisici, Area della Ricerca di Pisa, Via Moruzzi 1, 56124 Pisa (Italy); D' Ulivo, Alessandro [C.N.R. Istituto per i processi chimico-fisici, Area della Ricerca di Pisa, Via Moruzzi 1, 56124 Pisa (Italy); Tsalev, Dimiter L. [Faculty of Chemistry, University of Sofia, 1 James Bourchier Blvd., Sofia 1164 (Bulgaria)

    2005-07-15

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

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

    International Nuclear Information System (INIS)

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

    2005-01-01

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

  10. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT - FIELD PORTABLE GAS CHROMATOGRAPH/MASS SPECTROMETER - VIKING INSTRUMENTS CORPORATION

    Science.gov (United States)

    The performance evaluation of innovative and alternative environmental technologies is an integral part of the U.S. Environmental Protection Agency's (EPA) mission. Early efforts focused on evaluation technologies that supported the implementation of the Clean Air and Clean Wate...

  11. Miniature Gas Chromatograph Mass Spectrometer for In-Situ Resource Utilization, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — In situ resource utilization (ISRU) is essential for several of NASA's future flagship missions. Currently envisioned ISRU plants include production of oxygen from...

  12. Assays for chloramphenicol compared: radioenzymatic, gas chromatographic with electron capture, and gas chromatographic-mass specteometric

    International Nuclear Information System (INIS)

    Pickering, L.K.; Hoecker, J.L.; Kramer, W.G.; Liehr, J.G.; Caprioli, R.M.

    1979-01-01

    We compared these three techniques for measuring chloramphenicol in serum or urine. Although each has its particular advantages, any of them is shown to be satisfactory and may appropriately be used by clinical laboratories, according to the facilities available

  13. Spectrometric analyses in comparison to the physiological condition of heavy metal stressed floodplain vegetation in a standardised experiment

    Science.gov (United States)

    Götze, Christian; Jung, András; Merbach, Ines; Wennrich, Rainer; Gläßer, Cornelia

    2010-06-01

    Floodplain ecosystems are affected by flood dynamics, nutrient supply as well as anthropogenic activities. Heavy metal pollution poses a serious environmental challenge. Pollution transfer from the soil to vegetation is still present at the central location of Elbe River, Germany. The goal of this study was to assess and separate the current heavy metal contamination of the floodplain ecosystem, using spectrometric field and laboratory measurements. A standardized pot experiment with floodplain vegetation in differently contaminated soils provided the basis for the measurements. The dominant plant types of the floodplains are: Urtica dioica, Phalaris arundinacea and Alopecurus pratensis, these were also chemically analysed. Various vegetation indices and methods were used to estimate the red edge position, to normalise the spectral curve of the vegetation and to investigate the potential of different methods for separating plant stress in floodplain vegetation. The main task was to compare spectral bands during phenological phases to find a method to detect heavy metal stress in plants. A multi-level algorithm for the curve parameterisation was developed. Chemo-analytical and ecophysiological parameters of plants were considered in the results and correlated with spectral data. The results of this study show the influence of heavy metals on the spectral characteristics of the focal plants. The developed method (depth CR1730) showed significant relationship between the plants and the contamination.

  14. Certification of model spectrometric alpha sources (MSAS) and problems of the MSAS system improvement

    International Nuclear Information System (INIS)

    Belyatskij, A.F.; Gejdel'man, A.M.; Egorov, Yu.S.; Nedovesov, V.G.; Chechev, V.P.

    1984-01-01

    Results of certification of standard spectrometric alpha sources (SSAS) of industrial production are presented: methods for certification by main radiation physical parameters: proper halfwidth of α-lines, activity of radionuclides in the source, energies of α-particle emitting sources and relative intensity of different energy α-particle groups - are analysed. The advantage for the SSAS system improvement - a set of model measures for α-radiation, a collection of interconnected data units on physical, engineering and design characteristics of SSAS, methods for their obtaining and determination, on instruments used, is considered

  15. Sequential mass spectrometric analysis of uranium and plutonium employing resin bead technique

    International Nuclear Information System (INIS)

    Ramakumar, K.L.; Aggarwal, S.K.; Chitambar, S.A.; Jain, H.C.

    1985-01-01

    Sequential mass spectrometric analysis of uranium and plutonium employing anion exchange resin bead technique is reported using a high sensitive single stage magnetic analyser instrument, the routinely employed rhenium double filament assembly and 0.5M HNO 3 as a wetting agent for loading the resin beads. A precision of bettter than 0.3per cent (2sigma) is obtained on the isotopic ratio measurements. However, extreme care has to be exercised to carry the resin bead experiments under ultra clean conditions so as to avoid pick up of contamination. (author)

  16. Anomaly disentanglement on the basis of automatic processing of the aerial gamma-spectrometric survey data

    International Nuclear Information System (INIS)

    Perlovskij, V.A.; Zaika, S.D.; Lomtadze, V.V.

    1976-01-01

    Automated processing airborne gamma spectrometric data has been introduced with the use of the BESM-4 computer. Discrimination of anomalies is effected using a variable interval 200-300 m within which maximum values in the general counting channel and their coordinates are found; reference points are detected too against which one can determine the excess and amplitude of the anomalies. The discriminated anomalies are fixed on printer and charts of anomalies are constructed. The charts and tables characterizing the anomaly help in the identification of its potentialities and hence underlie a decision to start ground works

  17. A spectrometric approach in radiography for detection of materials by their effective atomic number

    CERN Document Server

    Ryzhikov, V D; Onyshchenko, G M; Lecoq, P; Smith, C F

    2009-01-01

    In this paper we report a spectrometric approach to dual-energy digital radiography that has been developed and applied to identify specific organic substances and discern small differences in their effective atomic number. An experimental setup has been designed, and a theoretical description proposed based on the experimental results obtained. The proposed method is based on the application of special reference samples made of materials with different effective atomic number and thickness parameters known to affect X-ray attenuation in the low-energy range. The results obtained can be used in the development of a new generation of multi-energy customs or medical X-ray scanners.

  18. Sideritis romana L. subsp. purpurea (Tal. ex Benth.) Heywood, a new chemotype from Montenegro.

    Science.gov (United States)

    Garzoli, Stefania; Božović, Mijat; Baldisserotto, Anna; Andreotti, Elisa; Pepi, Federico; Tadić, Vanja; Manfredini, Stefano; Ragno, Rino

    2018-05-01

    A study on essential oil fractions of the Western Balkan endemic Sideritis romana L. subsp. purpurea (Tal. ex Benth.) Heywood collected in Montenegro is reported. The 24-h systematic steam distillation extraction procedure was performed. The gas chromatographic/mass spectrometric (GC/MS) analysis of the fractions showed γ-elemene and spathulenol as two main constituents, revealing a new chemotype of this plant species. Although varying in the content of these two main compounds, which makes the fractions quite different between each other, evaluation of the anti-Candida activity showed the lack of any significant efficacy.

  19. Pharmacokinetic comparison of seven 8-methoxypsoralen brands

    DEFF Research Database (Denmark)

    Menne, T; Andersen, Klaus Ejner; Larsen, E

    1981-01-01

    The pharmacokinetics of seven 8-MOP brands were evaluated in 7 volunteers using an incomplete bloc design. After a single oral dose the 8-MOP plasma level was followed for 3 hours. The plasma concentration was measured with a gas chromatographic - mass spectrometric method, using an isotopic...... dilution technique. The different brands could be divided into three groups. Two gave a high maximum concentration, four a medium, and one a low concentration. The large interbrand variation observed in this study can explain the variations in the results of the treatment and the differing numbers...

  20. Quantitative mass fragmentographic determination of unlabeled and deuterium-labeled propoxyphene in plasma

    International Nuclear Information System (INIS)

    Sullivan, H.R.; McMahon, R.E.

    1977-01-01

    A quantitative gas chromatographic-mass spectrometric method for determination of plasma levels of d-propoxyphene has been developed by using d-propoxyphene-benzyl-d 7 as internal standard. Steady-state pharmacokinetics were studied in a dog by orally administering d-propoxyphene-d 0 for 19 days and d-propoxyphene-d 2 on the 20th day, and monitoring the plasma levels of both compounds and the ratio for 48 hours. It was established that the use of propoxyphene-d 2 did not lead to an isotope effect

  1. Mass-spectrometric exploration of proteome structure and function

    DEFF Research Database (Denmark)

    Aebersold, Ruedi; Mann, Matthias

    2016-01-01

    , the structures and functions of selected proteins have been studied using biochemical and biophysical methods. However, the properties and behaviour of the proteome as an integrated system have largely remained elusive. Powerful mass-spectrometry-based technologies now provide unprecedented insights...

  2. Gas Chromatography-Mass Spectrometric Analysis of Essential Oil ...

    African Journals Online (AJOL)

    Conclusion: The study indicates that the essential oil of G. parviflora aerial parts has a potential for development into a natural insecticide/nematicide for control of nematodes and grain storage insects. Keywords: Glycosmis parviflora, Essential oil, Meloidogyne incognita, Sitophilus zeamais, Triboliumcastaneum, Contact ...

  3. Classification of terverticillate Penicillia by electrospray mass spectrometric profiling

    DEFF Research Database (Denmark)

    Smedsgaard, Jørn; Hansen, Michael Edberg; Frisvad, Jens Christian

    2004-01-01

    429 isolates of 58 species belonging to Penicillium subgenus Penicillium are classified from direct infusion electrospray mass spectrometry (diMS) analysis of crude extracts by automated data processing. The study shows that about 70% of the species can be classified correctly into species using...

  4. A Multifaceted Mass Spectrometric Method to Probe Feeding Related Neuropeptide Changes in Callinectes sapidus and Carcinus maenas

    Science.gov (United States)

    Zhang, Yuzhuo; DeLaney, Kellen; Hui, Limei; Wang, Junhua; Sturm, Robert M.; Li, Lingjun

    2018-05-01

    Food intake is regulated by various neuromodulators, including numerous neuropeptides. However, it remains elusive at the molecular and cellular level as to how these important chemicals regulate internal processes and which regions of the neuronal organs are responsible for regulating the behavior. Here we report a comparative neuropeptidomic analysis of the brain and pericardial organ (PO) in response to feeding in two well-studied crustacean physiology model organisms, Callinectes sapidus and Carcinus maenas, using mass spectrometry (MS) techniques. A multifaceted MS-based approach has been developed to obtain complementary information on the expression changes of a large array of neuropeptides in the brain and PO. The method employs stable isotope labeling of brain and PO extracts for relative MS quantitation, capillary electrophoresis (CE)-MS for fractionation and high-specificity analysis, and mass spectrometric imaging (MSI) for in-situ molecular mapping of peptides. A number of neuropeptides, including RFamides, B-type allatostatins (AST-B), RYamides, and orcokinins exhibit significant changes in abundance after feeding in this investigation. Peptides from the AST-B family found in PO tissue were shown to have both altered expression and localization changes after feeding, indicating that they may be a class of vital neuropeptide regulators involved in feeding behavior. [Figure not available: see fulltext.

  5. Mass spectrometric characterization of circulating and functional antigens derived from piperacillin in patients with cystic fibrosis1

    Science.gov (United States)

    Whitaker, Paul; Meng, Xiaoli; Lavergne, Sidonie N.; El-Ghaiesh, Sabah; Monshi, Manal; Earnshaw, Caroline; Peckham, Daniel; Gooi, Jimmy; Conway, Steve; Pirmohamed, Munir; Jenkins, Rosalind E.; Naisbitt, Dean J.; Park, B. Kevin

    2011-01-01

    A mechanistic understanding of the relationship between the chemistry of drug antigen formation and immune function is lacking. Thus, mass spectrometric methods were employed to detect and fully characterize circulating antigens derived from piperacillin in patients undergoing therapy and the nature of the drug derived-epitopes on protein which can function as an antigen to stimulate T-cells. Albumin modification with piperacillin in vitro resulted in the formation of two distinct haptens, one formed directly from piperacillin and a second in which the dioxopiperazine ring had undergone hydrolysis. Modification was time- and concentration-dependent, with selective modification of Lys541 observed at low concentrations, whereas at higher concentrations up to 13/59 lysine residues were modified, four of which (Lys190, 195, 432 and 541) were detected in patients’ plasma. Piperacillin-specific T-lymphocyte responses (proliferation, cytokines and granzyme-B release) were detected ex vivo with cells from hypersensitive patients, and analysis of incubation medium showed that modification of the same lysine residues in albumin occurred in situ. The antigenicity of piperacillin-modified albumin was confirmed by stimulation of T-cells with characterized synthetic conjugates. Analysis of minimally-modified T-cell stimulatory albumin conjugates revealed peptide sequences incorporating Lys190, 432 and 541 as principal functional epitopes for T-cells. This study has characterized the multiple haptenic structures on albumin in patients, and showed that they constitute functional antigenic determinants for T-cells. PMID:21606251

  6. A Multifaceted Mass Spectrometric Method to Probe Feeding Related Neuropeptide Changes in Callinectes sapidus and Carcinus maenas

    Science.gov (United States)

    Zhang, Yuzhuo; DeLaney, Kellen; Hui, Limei; Wang, Junhua; Sturm, Robert M.; Li, Lingjun

    2018-02-01

    Food intake is regulated by various neuromodulators, including numerous neuropeptides. However, it remains elusive at the molecular and cellular level as to how these important chemicals regulate internal processes and which regions of the neuronal organs are responsible for regulating the behavior. Here we report a comparative neuropeptidomic analysis of the brain and pericardial organ (PO) in response to feeding in two well-studied crustacean physiology model organisms, Callinectes sapidus and Carcinus maenas, using mass spectrometry (MS) techniques. A multifaceted MS-based approach has been developed to obtain complementary information on the expression changes of a large array of neuropeptides in the brain and PO. The method employs stable isotope labeling of brain and PO extracts for relative MS quantitation, capillary electrophoresis (CE)-MS for fractionation and high-specificity analysis, and mass spectrometric imaging (MSI) for in-situ molecular mapping of peptides. A number of neuropeptides, including RFamides, B-type allatostatins (AST-B), RYamides, and orcokinins exhibit significant changes in abundance after feeding in this investigation. Peptides from the AST-B family found in PO tissue were shown to have both altered expression and localization changes after feeding, indicating that they may be a class of vital neuropeptide regulators involved in feeding behavior. [Figure not available: see fulltext.

  7. Mass spectrometric detection of 27-hydroxycholesterol in breast cancer exosomes.

    Science.gov (United States)

    Roberg-Larsen, Hanne; Lund, Kaja; Seterdal, Kristina Erikstad; Solheim, Stian; Vehus, Tore; Solberg, Nina; Krauss, Stefan; Lundanes, Elsa; Wilson, Steven Ray

    2017-05-01

    Exosomes from cancer cells are rich sources of biomarkers and may contain elevated levels of lipids of diagnostic value. 27-Hydroxycholesterol (27-OHC) is associated with proliferation and metastasis in estrogen receptor positive (ER+) breast cancer. In this study, we investigated the levels of 27-OHC, and other sidechain-hydroxylated oxysterols in exosomes. To study both cytoplasmic and exosomal oxysterol samples of limited size, we have developed a capillary liquid chromatography-mass spectrometry platform that outperforms our previously published systems regarding chromatographic resolution, analysis time and sensitivity. In the analyzed samples, the quantified level of cytoplasmic 27-OHC using this platform fitted with mRNA levels of 27-OHC's corresponding enzyme, CYP27A1. We find clearly increased levels of 27-OHC in exosomes (i.e., enrichment) from an ER+ breast cancer cell line (MCF-7) compared to exosomes derived from an estrogen receptor (ER-) breast cancer cell line (MDA-MB-231) and other control exosomes (non-cancerous cell line (HEK293) and human pooled serum). The exosomal oxysterol profile did not reflect cytoplasmic oxysterol profiles in the cells of origin; cytoplasmic 27-OHC was low in ER+ MCF-7 cells while high in MDA-MB-231 cells. Other control cancer cells showed varied cytoplasmic oxysterol levels. Hence, exosome profiling in cancer cells might provide complementary information with the possibility of diagnostic value. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Assessment of current mass spectrometric workflows for the quantification of low abundant proteins and phosphorylation sites

    Directory of Open Access Journals (Sweden)

    Manuel Bauer

    2015-12-01

    Full Text Available The data described here provide a systematic performance evaluation of popular data-dependent (DDA and independent (DIA mass spectrometric (MS workflows currently used in quantitative proteomics. We assessed the limits of identification, quantification and detection for each method by analyzing a dilution series of 20 unmodified and 10 phosphorylated synthetic heavy labeled reference peptides, respectively, covering six orders of magnitude in peptide concentration with and without a complex human cell digest background. We found that all methods performed very similarly in the absence of background proteins, however, when analyzing whole cell lysates, targeted methods were at least 5–10 times more sensitive than directed or DDA methods. In particular, higher stage fragmentation (MS3 of the neutral loss peak using a linear ion trap increased dynamic quantification range of some phosphopeptides up to 100-fold. We illustrate the power of this targeted MS3 approach for phosphopeptide monitoring by successfully quantifying 9 phosphorylation sites of the kinetochore and spindle assembly checkpoint component Mad1 over different cell cycle states from non-enriched pull-down samples. The data are associated to the research article ‘Evaluation of data-dependent and data-independent mass spectrometric workflows for sensitive quantification of proteins and phosphorylation sites׳ (Bauer et al., 2014 [1]. The mass spectrometry and the analysis dataset have been deposited to the ProteomeXchange Consortium (http://proteomecentral.proteomexchange.org via the PRIDE partner repository with the dataset identifier PXD000964.

  9. Determination of plutonium-241 half-life by mass spectrometric measurement

    International Nuclear Information System (INIS)

    Hiyama, Takashi; Wada, Yukio; Onishi, Koichi

    1982-01-01

    Much data for Pu-241 half-life have been reported, but these values range from 13.8 years to 15.1 years depending on investigators. In order to define the half-life of Pu-241, the half-life was calculated by analyzing the mass spectrometry data obtained in the author's laboratory over the past six years on Plutonium Isotopic Standard Reference Materials prepared at the National Bureau of Standards (NBS). The sample used for this work consisted of SRM-947 and SRM-948 prepared at NBS. Before mass spectrometric analysis, the plutonium aliquot was separated from its Am-241 daughter by anion exchange chromatography, since Am-241 is not distinguished from Pu-241 in the mass spectrometer. 241 Pu/ 239 Pu and 241 Pu/ 240 Pu ratios were calculated from the values of mass spectrometric measurement. From the relation of log N to time, the half-life of Pu-241 was determined, based on the slope using a least squares fit. The half-life of Pu-241 was estimated to be 14.29+-0.15 years. (Yoshitake, I.)

  10. Measurement of spectrometric magnet field of EXCHARM setup

    International Nuclear Information System (INIS)

    Aleev, A.N.; Balandin, V.P.; Bordyukov, A.A.

    1998-01-01

    The EXCHARM spectrometer is used for studying charm, strange and exotic hadrons. It is located at the neutron 5N channel of U-70 accelerator (Protvino). The EXCHARM dipole magnet has external size 4.486 x 3.196 x 3.058 m 3 with aperture 2.74 x 0.489 m 2 . The field measurement was made by three-component Hall magnetometer on-line computer in measurement region 2.40 x 0.32 x 3.78 m 3 . The apparatus and methods of the field measuring are described. The results of the measurements of the magnetic field are presented. The estimation of the measurement precision is given. (author)

  11. Mass spectrometric diagnosis of an atmospheric pressure helium microplasma jet

    International Nuclear Information System (INIS)

    McKay, K; Oh, J-S; Walsh, J L; Bradley, J W

    2013-01-01

    Ambient molecular beam mass spectrometry (MBMS) has been used to study how different capillary widths (530 µm and 2.4 mm) and excitation waveforms (continuous wave kHz and pulsed dc) affect the ionic composition of atmospheric pressure plasma jets. It is shown from time-averaged ion intensities that reducing the width of the jet capillary results in a significant increase in the variety of both positive and negative ions detected within the discharge. We discuss this in terms of changes in flow velocity and the onset of turbulence within the plasma plume. Changing the mode of excitation had little effect on the ionic species detected from the microplasma jet; however, there was a notable shift in dominance towards higher mass ions when operated in a continuous wave kHz mode. The temporal evolution of the ions within the microplasma jet was observed for both excitation sources, operated at 5 and 15 kHz. Positive ions were created during periods correlated with the positive and negative peaks in discharge current, while negative ions were predominantly created at times when the discharge current peak was negative. This phenomenon was independent of the driving waveform. For pulsed dc excitation, considerably fewer positive ions were created in periods related to the negative current peaks, especially at higher frequencies. We propose a simple explanation for these processes based on ideas of streamer propagation and the influence of self-induced electric fields in the plasma plume. (paper)

  12. Tandem mass spectrometric analysis of cyclophosphamide, ifosfamide and their metabolites.

    Science.gov (United States)

    Liu, Zhongfa; Chan, Kenneth K; Wang, Jeffrey J

    2005-01-01

    A detailed multi-stage (MSn) fragmentation study of cyclophosphamide (CP), ifosfamide (IF) and their major metabolites, using an ion-trap mass spectrometer and a Q-TOF mass spectrometer, was performed with the aid of specifically deuterium-labeled analogs. The analytes showed good responses in positive-ion electrospray mass spectrometry as [MH]+ ions. Tandem mass spectra revealed a wealth of structurally specific ions, allowing characterization of the fragmentation pathways of these analytes. The major fragmentation pathways of the protonated CP and IF are elimination of ethylene from C5 and C6 of 1,3,2-oxazaphosphorine-2-oxide via a McLafferty rearrangement, and cleavage of the P-N bond. However, their activated 4-OOH and 4-OH metabolites primarily underwent hydrogen peroxide elimination and dehydration, respectively, followed by fragmentation pathways similar to those of CP and IF. These results should prove useful in structural elucidation of future analogs of CP and IF, and/or of their metabolites. Copyright (c) 2005 John Wiley & Sons, Ltd.

  13. Mass spectrometric investigation of evaporation of lithium-vanadium bronze

    International Nuclear Information System (INIS)

    Kudin, L.S.; Pogrebnoj, A.M.

    1996-01-01

    The composition of ionic and neutral components of vapour above lithium-vanadium bronze Li 0.2 VO 2.6 has been studied. It is ascertained that molecules of LiVO 3 and O 2 and Li + ions (2.2±0.2); Li + ·LiVO 3 (2.4±0.3); Li + ·(LiVO 3 ) 2 (2.4±0.9); Li + ·V 2 O 5 (2.3±0.9); Cs + (2.1±0.3); Cs + ·LiVO 3 (2.6±1.0) are basic components of saturated vapour, the values of ionic work functions in eV are given in parentheses. Sublimation enthalpy of lithium metavanadate Δ S H 0 (LiVO 3 , 298 K)=457±30 kJ/mol and its formation enthalpy Δ f H 0 (LiVO 3 , gas, 298 k)=-704±30 kJ/mol. have been defined. Using law 2 of thermodynamics the enthalpies of ion-molecular reactions have been defined. ion formation enthalpies being calculated on their basis. 18 refs., 3 figs., 3 tabs

  14. Improved spectrometric characteristics of thallium bromide nuclear radiation detectors

    CERN Document Server

    Hitomi, K; Shoji, T; Suehiro, T; Hiratate, Y

    1999-01-01

    Thallium bromide (TlBr) is a compound semiconductor with a high atomic number and wide band gap. In this study, nuclear radiation detectors have been fabricated from the TlBr crystals. The TlBr crystals were grown by the horizontal travelling molten zone (TMZ) method using the materials purified by many pass zone refining. The crystals were characterized by measuring the resistivity, the mobility-lifetime (mu tau) product and the energy required to create an electron-hole pair (the epsilon value). Improved energy resolution has been obtained by the TlBr radiation detectors. At room temperature the full-width at half-maximum (FWHM) for the 59.5, 122 and 662 keV gamma-ray photo peak obtained from the detectors were 3.3, 8.8 and 29.5 keV, respectively. By comparing the saturated peak position of the TlBr detector with that of the CdTe detector, the epsilon value has been estimated to be about 5.85 eV for the TlBr crystal.

  15. Quantitative mass spectrometric analysis of glycoproteins combined with enrichment methods.

    Science.gov (United States)

    Ahn, Yeong Hee; Kim, Jin Young; Yoo, Jong Shin

    2015-01-01

    Mass spectrometry (MS) has been a core technology for high sensitive and high-throughput analysis of the enriched glycoproteome in aspects of quantitative assays as well as qualitative profiling of glycoproteins. Because it has been widely recognized that aberrant glycosylation in a glycoprotein may involve in progression of a certain disease, the development of efficient analysis tool for the aberrant glycoproteins is very important for deep understanding about pathological function of the glycoprotein and new biomarker development. This review first describes the protein glycosylation-targeting enrichment technologies mainly employing solid-phase extraction methods such as hydrizide-capturing, lectin-specific capturing, and affinity separation techniques based on porous graphitized carbon, hydrophilic interaction chromatography, or immobilized boronic acid. Second, MS-based quantitative analysis strategies coupled with the protein glycosylation-targeting enrichment technologies, by using a label-free MS, stable isotope-labeling, or targeted multiple reaction monitoring (MRM) MS, are summarized with recent published studies. © 2014 The Authors. Mass Spectrometry Reviews Published by Wiley Periodicals, Inc.

  16. Sample handling for mass spectrometric proteomic investigations of human urine.

    Science.gov (United States)

    Petri, Anette Lykke; Høgdall, Claus; Christensen, Ib Jarle; Simonsen, Anja Hviid; T'jampens, Davy; Hellmann, Marja-Leena; Kjaer, Susanne Krüger; Fung, Eric T; Høgdall, Estrid

    2008-09-01

    Because of its non-invasive sample collection method, human urine is an attractive biological material both for discovering biomarkers and for use in future screening trials for different diseases. Before urine can be used for these applications, standardized protocols for sample handling that optimize protein stability are required. In this explorative study, we examine the influence of different urine collection methods, storage temperatures, storage times, and repetitive freeze-thaw procedures on the protein profiles obtained by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS). Prospectively collected urine samples from 11 women were collected as either morning or midday specimens. The effects of storage temperature, time to freezing, and freeze-thaw cycles were assessed by calculating the number, intensity, and reproducibility of peaks visualized by SELDI-TOF-MS. On the CM10 array, 122 peaks were detected and 28 peaks were found to be significantly different between urine types, storage temperature and time to freezing. On the IMAC-Cu array, 65 peaks were detected and 1 peak was found to be significantly different according to time to freezing. No significant differences were demonstrated for freeze-thaw cycles. Optimal handling and storage conditions are necessary in clinical urine proteomic investigations. Collection of urine with a single and consistently performed protocol is needed to reduce analytical bias. Collecting only one urine type, which is stored for a limited period at 4°C until freezing at -80°C prior to analysis will provide the most stable profiles. Copyright © 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Mass spectrometric based approaches in urine metabolomics and biomarker discovery.

    Science.gov (United States)

    Khamis, Mona M; Adamko, Darryl J; El-Aneed, Anas

    2017-03-01

    Urine metabolomics has recently emerged as a prominent field for the discovery of non-invasive biomarkers that can detect subtle metabolic discrepancies in response to a specific disease or therapeutic intervention. Urine, compared to other biofluids, is characterized by its ease of collection, richness in metabolites and its ability to reflect imbalances of all biochemical pathways within the body. Following urine collection for metabolomic analysis, samples must be immediately frozen to quench any biogenic and/or non-biogenic chemical reactions. According to the aim of the experiment; sample preparation can vary from simple procedures such as filtration to more specific extraction protocols such as liquid-liquid extraction. Due to the lack of comprehensive studies on urine metabolome stability, higher storage temperatures (i.e. 4°C) and repetitive freeze-thaw cycles should be avoided. To date, among all analytical techniques, mass spectrometry (MS) provides the best sensitivity, selectivity and identification capabilities to analyze the majority of the metabolite composition in the urine. Combined with the qualitative and quantitative capabilities of MS, and due to the continuous improvements in its related technologies (i.e. ultra high-performance liquid chromatography [UPLC] and hydrophilic interaction liquid chromatography [HILIC]), liquid chromatography (LC)-MS is unequivocally the most utilized and the most informative analytical tool employed in urine metabolomics. Furthermore, differential isotope tagging techniques has provided a solution to ion suppression from urine matrix thus allowing for quantitative analysis. In addition to LC-MS, other MS-based technologies have been utilized in urine metabolomics. These include direct injection (infusion)-MS, capillary electrophoresis-MS and gas chromatography-MS. In this article, the current progresses of different MS-based techniques in exploring the urine metabolome as well as the recent findings in providing

  18. A Caenorhabditis elegans Mass Spectrometric Resource for Neuropeptidomics

    Science.gov (United States)

    Van Bael, Sven; Zels, Sven; Boonen, Kurt; Beets, Isabel; Schoofs, Liliane; Temmerman, Liesbet

    2018-01-01

    Neuropeptides are important signaling molecules used by nervous systems to mediate and fine-tune neuronal communication. They can function as neurotransmitters or neuromodulators in neural circuits, or they can be released as neurohormones to target distant cells and tissues. Neuropeptides are typically cleaved from larger precursor proteins by the action of proteases and can be the subject of post-translational modifications. The short, mature neuropeptide sequences often entail the only evolutionarily reasonably conserved regions in these precursor proteins. Therefore, it is particularly challenging to predict all putative bioactive peptides through in silico mining of neuropeptide precursor sequences. Peptidomics is an approach that allows de novo characterization of peptides extracted from body fluids, cells, tissues, organs, or whole-body preparations. Mass spectrometry, often combined with on-line liquid chromatography, is a hallmark technique used in peptidomics research. Here, we used an acidified methanol extraction procedure and a quadrupole-Orbitrap LC-MS/MS pipeline to analyze the neuropeptidome of Caenorhabditis elegans. We identified an unprecedented number of 203 mature neuropeptides from C. elegans whole-body extracts, including 35 peptides from known, hypothetical, as well as from completely novel neuropeptide precursor proteins that have not been predicted in silico. This set of biochemically verified peptide sequences provides the most elaborate C. elegans reference neurpeptidome so far. To exploit this resource to the fullest, we make our in-house database of known and predicted neuropeptides available to the community as a valuable resource. We are providing these collective data to help the community progress, amongst others, by supporting future differential and/or functional studies.

  19. A Caenorhabditis elegans Mass Spectrometric Resource for Neuropeptidomics

    Science.gov (United States)

    Van Bael, Sven; Zels, Sven; Boonen, Kurt; Beets, Isabel; Schoofs, Liliane; Temmerman, Liesbet

    2018-05-01

    Neuropeptides are important signaling molecules used by nervous systems to mediate and fine-tune neuronal communication. They can function as neurotransmitters or neuromodulators in neural circuits, or they can be released as neurohormones to target distant cells and tissues. Neuropeptides are typically cleaved from larger precursor proteins by the action of proteases and can be the subject of post-translational modifications. The short, mature neuropeptide sequences often entail the only evolutionarily reasonably conserved regions in these precursor proteins. Therefore, it is particularly challenging to predict all putative bioactive peptides through in silico mining of neuropeptide precursor sequences. Peptidomics is an approach that allows de novo characterization of peptides extracted from body fluids, cells, tissues, organs, or whole-body preparations. Mass spectrometry, often combined with on-line liquid chromatography, is a hallmark technique used in peptidomics research. Here, we used an acidified methanol extraction procedure and a quadrupole-Orbitrap LC-MS/MS pipeline to analyze the neuropeptidome of Caenorhabditis elegans. We identified an unprecedented number of 203 mature neuropeptides from C. elegans whole-body extracts, including 35 peptides from known, hypothetical, as well as from completely novel neuropeptide precursor proteins that have not been predicted in silico. This set of biochemically verified peptide sequences provides the most elaborate C. elegans reference neurpeptidome so far. To exploit this resource to the fullest, we make our in-house database of known and predicted neuropeptides available to the community as a valuable resource. We are providing these collective data to help the community progress, amongst others, by supporting future differential and/or functional studies. [Figure not available: see fulltext.

  20. Characterization of organic and conventional sweet basil leaves using chromatographic and flow-injection mass spectrometric (FIMS) fingerprints combined with principal component analysis

    Science.gov (United States)

    Lu, Yingjian; Gao, Boyan; Chen, Pei; Charles, Denys; Yu, Liangli (Lucy)

    2014-01-01

    Sweet basil, Ocimum basilicum., is one of the most important and wildly used spices and has been shown to have antioxidant, antibacterial, and anti-diarrheal activities. In this study, high performance liquid chromatographic (HPLC) and flow-injection mass spectrometric (FIMS) fingerprinting techniques were used to differentiate organic and conventional sweet basil leaf samples. Principal component analysis (PCA) of the fingerprints indicated that both HPLC and FIMS fingerprints could effectively detect the chemical differences in the organic and conventional sweet basil leaf samples. This study suggested that the organic basil sample contained greater concentrations of almost all the major compounds than its conventional counterpart on a per same botanical weight basis. The FIMS method was able to rapidly differentiate the organic and conventional sweet basil leaf samples (1 min analysis time), whereas the HPLC fingerprints provided more information about the chemical composition of the basil samples with a longer analytical time. PMID:24518341

  1. Characterization of used lubricating oil by spectrometric techniques

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Andressa Moreira de, E-mail: andressa@ctaa.embrapa.br [Embrapa Agroindustria de Alimentos, Guaratiba, Rio de Janeiro, RJ (Brazil); Correa, Sergio Machado [Faculdade de Engenharia. Universidade do Estado do Rio de Janeiro (UERJ), Resende, RJ (Brazil); Silva, Glauco Correa da [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2011-07-01

    Full text: The engine lubricating oil drags all kinds of impurities generated by wear of internal components. Thus, it is necessary to monitor the physical and chemical properties and concentration of metals in lubricants used to determine the appropriate time to replace them. Moreover, one can monitor the wear of the engines through the levels of metals in oils. To achieve these goals, some detection techniques such as Flame atomic absorption spectrometry (FAAS), Inductively coupled plasma optical emission spectrometry (ICP-OES) and X-ray fluorescence (XRF), have been widely used to determine metals in lubricating oils and also in other oil derivatives. Thus, some of these techniques were used in this study. Also the technique used was Gas chromatography mass spectrometry (GC / MS) for characterization of chromatographic profile of the engine lubricating oil after use. Through the technique of ICP-OES for method of United States Environmental Protection Agency (USEPA) METHOD 6010B - Inductively coupled plasma optical emission spectrometry was performed to characterize metals in lubricating oil motor, using equipment from ICP-OES Perkin-Elmer{sup R} OPTIMA 3000 ICP-Winlab and software, obtaining the following identification of metals: barium (Ba), calcium (Ca), lead (Pb), copper (Cu), Chromium (Cr), iron (Fe), magnesium (Mg), molybdenum (Mo) and zinc (Zn). Using the XRF technique, through the equipment EDFRX Shimadzu{sup R} model 800HS EDX, Rh tube, applied voltage of 50kV, amperage 100{mu}A, detector Si (Li) cooled with liquid nitrogen and collimator 10mm, we analyzed all the components comprised in the range of Ti to U and Na to SC, identified the following metals: calcium (Ca), zinc (Zn), iron (Fe), copper (Cu), molybdenum (Mo) and nickel (Ni). The characterization was performed by chromatographic methods: USEPA METHOD 5021A - Volatile organic compounds in various sample matrices using equilibrium headspace analysis, USEPA METHOD 8015B - Nonhalogenated Organics

  2. Characterization of used lubricating oil by spectrometric techniques

    International Nuclear Information System (INIS)

    Souza, Andressa Moreira de; Correa, Sergio Machado; Silva, Glauco Correa da

    2011-01-01

    Full text: The engine lubricating oil drags all kinds of impurities generated by wear of internal components. Thus, it is necessary to monitor the physical and chemical properties and concentration of metals in lubricants used to determine the appropriate time to replace them. Moreover, one can monitor the wear of the engines through the levels of metals in oils. To achieve these goals, some detection techniques such as Flame atomic absorption spectrometry (FAAS), Inductively coupled plasma optical emission spectrometry (ICP-OES) and X-ray fluorescence (XRF), have been widely used to determine metals in lubricating oils and also in other oil derivatives. Thus, some of these techniques were used in this study. Also the technique used was Gas chromatography mass spectrometry (GC / MS) for characterization of chromatographic profile of the engine lubricating oil after use. Through the technique of ICP-OES for method of United States Environmental Protection Agency (USEPA) METHOD 6010B - Inductively coupled plasma optical emission spectrometry was performed to characterize metals in lubricating oil motor, using equipment from ICP-OES Perkin-Elmer R OPTIMA 3000 ICP-Winlab and software, obtaining the following identification of metals: barium (Ba), calcium (Ca), lead (Pb), copper (Cu), Chromium (Cr), iron (Fe), magnesium (Mg), molybdenum (Mo) and zinc (Zn). Using the XRF technique, through the equipment EDFRX Shimadzu R model 800HS EDX, Rh tube, applied voltage of 50kV, amperage 100μA, detector Si (Li) cooled with liquid nitrogen and collimator 10mm, we analyzed all the components comprised in the range of Ti to U and Na to SC, identified the following metals: calcium (Ca), zinc (Zn), iron (Fe), copper (Cu), molybdenum (Mo) and nickel (Ni). The characterization was performed by chromatographic methods: USEPA METHOD 5021A - Volatile organic compounds in various sample matrices using equilibrium headspace analysis, USEPA METHOD 8015B - Nonhalogenated Organics Using GC

  3. Study of disulfide reduction and alkyl chloroformate derivatization of plasma sulfur amino acids using gas chromatography-mass spectrometry.

    Science.gov (United States)

    Svagera, Zdeněk; Hanzlíková, Dagmar; Simek, Petr; Hušek, Petr

    2012-03-01

    Four disulfide-reducing agents, dithiothreitol (DTT), 2,3-dimercaptopropanesulfonate (DMPS), and the newly tested 2-mercaptoethanesulfonate (MESNA) and Tris(hydroxypropyl)phosphine (THP), were investigated in detail for release of sulfur amino acids in human plasma. After protein precipitation with trichloroacetic acid (TCA), the plasma supernatant was treated with methyl, ethyl, or propyl chloroformate via the well-proven derivatization-extraction technique and the products were subjected to gas chromatographic-mass spectrometric (GC-MS) analysis. All the tested agents proved to be rapid and effective reducing agents for the assay of plasma thiols. When compared with DTT, the novel reducing agents DMPS, MESNA, and THP provided much cleaner extracts and improved analytical performance. Quantification of homocysteine, cysteine, and methionine was performed using their deuterated analogues, whereas other analytes were quantified by means of 4-chlorophenylalanine. Precise and reliable assay of all examined analytes was achieved, irrespective of the chloroformate reagent used. Average relative standard deviations at each analyte level were ≤6%, quantification limits were 0.1-0.2 μmol L(-1), recoveries were 94-121%, and linearity was over three orders of magnitude (r(2) equal to 0.997-0.998). Validation performed with the THP agent and propyl chloroformate derivatization demonstrated the robustness and reliability of this simple sample-preparation methodology.

  4. Mass spectrometric confirmation criterion for product-ion spectra generated in flow-injection analysis. Environmental application

    NARCIS (Netherlands)

    Geerdink, R.B.; Niessen, W.M.A.; Brinkman, U.A.T.

    2001-01-01

    The suitability of a confirmation criterion recently recommended in the Netherlands for gas chromatography with mass spectrometric detection (GC-MS), was evaluated for flow-injection analysis (FIA) with atmospheric pressure chemical ionisation MS-MS detection. The main feature of the criterion is

  5. A liquid chromatography-mass spectrometric method for the determination of oak moss allergens atranol and chloroatranol in perfumes

    DEFF Research Database (Denmark)

    Bossi, Rossana; Rastogi, Suresh Chandra; Bernard, Guillaume

    2004-01-01

    This paper describes a validated liquid chromatographic-tandem mass spectrometric method for quantitative analysis of the potential oak moss allergens atranol and chloroatranol in perfumes and similar products. The method employs LC-MS-MS with electrospray ionization (ESI) in negative mode...

  6. Determination of isotope fractionation effect using a double spike (242Pu+240Pu) during the mass spectrometric analysis of plutonium

    International Nuclear Information System (INIS)

    Chitambar, S.A.; Parab, A.R.; Khodade, P.S.; Jain, H.C.

    1986-01-01

    Isotope fractionation effect during the mass spectrometric analysis of plutonium has been investigated using a double spike ( 242 Pu+ 240 Pu) and the determination of concentration of plutonium in dissolver solution of irradiated fuel is reported. (author). 6 refs., 2 tables

  7. Research of Spectrometric and Exploitation Characteristics of BGO-PMP-165 Scintiblock in Temperature Interval from +25 to -140$^{o}$C

    CERN Document Server

    Ainbund, M R; Gundorin, N A; Matveev, D V; Serov, D G

    2001-01-01

    Photomultipliers based on microchannel plates are used for fast systems which form time marks of physical setups as well as in special technical areas. It is not uncommon when they substitute traditional dynode system photomultipliers. The possibility of compatible work of the PMP-165 photomultiplier with BGO crystal which were cooled down to temperature necessary for appropriate functioning of a semiconductor Ge detector with taking into account of temperature dependencies of own PMP characteristics is investigated during experiment. Cooling down of the system from room temperature down to v140^{o}C during 8 hours is done. Lower limit of temperature which allows PMP to function properly is registered. Changes of spectrometric characteristics caused by temperature are studied.

  8. Separation of silver ions and starch modified silver nanoparticles using high performance liquid chromatography with ultraviolet and inductively coupled mass spectrometric detection

    International Nuclear Information System (INIS)

    Hanley, Traci A.; Saadawi, Ryan; Zhang, Peng; Caruso, Joseph A.; Landero-Figueroa, Julio

    2014-01-01

    The production of commercially available products marketed to contain silver nanoparticles is rapidly increasing. Species-specific toxicity is a phenomenon associated with many elements, including silver, making it imperative to develop a method to identify and quantify the various forms of silver (namely, silver ions vs. silver nanoparticles) possibly present in these products. In this study a method was developed using high performance liquid chromatography (HPLC) with ultraviolet (UV–VIS) and inductively coupled mass spectrometric (ICP-MS) detection to separate starch stabilized silver nanoparticles (AgNPs) and silver ions (Ag + ) by cation exchange chromatography with 0.5 M nitric acid mobile phase. The silver nanoparticles and ions were baseline resolved with an ICP-MS response linear over four orders of magnitude, 0.04 mg kg −1 detection limit, and 90% chromatographic recovery for silver solutions containing ions and starch stabilized silver nanoparticles smaller than 100 nm

  9. Separation of silver ions and starch modified silver nanoparticles using high performance liquid chromatography with ultraviolet and inductively coupled mass spectrometric detection

    Energy Technology Data Exchange (ETDEWEB)

    Hanley, Traci A.; Saadawi, Ryan; Zhang, Peng; Caruso, Joseph A., E-mail: joseph.caruso@uc.edu; Landero-Figueroa, Julio

    2014-10-01

    The production of commercially available products marketed to contain silver nanoparticles is rapidly increasing. Species-specific toxicity is a phenomenon associated with many elements, including silver, making it imperative to develop a method to identify and quantify the various forms of silver (namely, silver ions vs. silver nanoparticles) possibly present in these products. In this study a method was developed using high performance liquid chromatography (HPLC) with ultraviolet (UV–VIS) and inductively coupled mass spectrometric (ICP-MS) detection to separate starch stabilized silver nanoparticles (AgNPs) and silver ions (Ag{sup +}) by cation exchange chromatography with 0.5 M nitric acid mobile phase. The silver nanoparticles and ions were baseline resolved with an ICP-MS response linear over four orders of magnitude, 0.04 mg kg{sup −1} detection limit, and 90% chromatographic recovery for silver solutions containing ions and starch stabilized silver nanoparticles smaller than 100 nm.

  10. Vis-NIR spectrometric determination of Brix and sucrose in sugar production samples using kernel partial least squares with interval selection based on the successive projections algorithm.

    Science.gov (United States)

    de Almeida, Valber Elias; de Araújo Gomes, Adriano; de Sousa Fernandes, David Douglas; Goicoechea, Héctor Casimiro; Galvão, Roberto Kawakami Harrop; Araújo, Mario Cesar Ugulino

    2018-05-01

    This paper proposes a new variable selection method for nonlinear multivariate calibration, combining the Successive Projections Algorithm for interval selection (iSPA) with the Kernel Partial Least Squares (Kernel-PLS) modelling technique. The proposed iSPA-Kernel-PLS algorithm is employed in a case study involving a Vis-NIR spectrometric dataset with complex nonlinear features. The analytical problem consists of determining Brix and sucrose content in samples from a sugar production system, on the basis of transflectance spectra. As compared to full-spectrum Kernel-PLS, the iSPA-Kernel-PLS models involve a smaller number of variables and display statistically significant superiority in terms of accuracy and/or bias in the predictions. Published by Elsevier B.V.

  11. Mass Spectrometric Calibration of Controlled Fluoroform Leak Rate Devices Technique and Uncertainty Analysis

    CERN Document Server

    Balsley, S D; Laduca, C A

    2003-01-01

    Controlled leak rate devices of fluoroform on the order of 10 sup - sup 8 atm centre dot cc sec sup - sup 1 at 25 C are used to calibrate QC-1 War Reserve neutron tube exhaust stations for leak detection sensitivity. Close-out calibration of these tritium-contaminated devices is provided by the Gas Dynamics and Mass Spectrometry Laboratory, Organization 14406, which is a tritium analytical facility. The mass spectrometric technique used for the measurement is discussed, as is the first principals calculation (pressure, volume, temperature and time). The uncertainty of the measurement is largely driven by contributing factors in the determination of P, V and T. The expanded uncertainty of the leak rate measurement is shown to be 4.42%, with a coverage factor of 3 (k=3).

  12. Separation Techniques for Uranium and Plutonium at Trace Levels for the Thermal Ionization Mass Spectrometric Determination

    International Nuclear Information System (INIS)

    Suh, M. Y.; Han, S. H.; Kim, J. G.; Park, Y. J.; Kim, W. H.

    2005-12-01

    This report describes the state of the art and the progress of the chemical separation and purification techniques required for the thermal ionization mass spectrometric determination of uranium and plutonium in environmental samples at trace or ultratrace levels. Various techniques, such as precipitation, solvent extraction, extraction chromatography, and ion exchange chromatography, for separation of uranium and plutonium were evaluated. Sample preparation methods and dissolution techniques for environmental samples were also discussed. Especially, both extraction chromatographic and anion exchange chromatographic procedures for uranium and plutonium in environmental samples, such as soil, sediment, plant, seawater, urine, and bone ash were reviewed in detail in order to propose some suitable methods for the separation and purification of uranium and plutonium from the safeguards environmental or swipe samples. A survey of the IAEA strengthened safeguards system, the clean room facility of IAEA's NWAL(Network of Analytical Laboratories), and the analytical techniques for safeguards environmental samples was also discussed here

  13. Identification of volatiles by headspace gas chromatography with simultaneous flame ionization and mass spectrometric detection.

    Science.gov (United States)

    Tiscione, Nicholas B; Yeatman, Dustin Tate; Shan, Xiaoqin; Kahl, Joseph H

    2013-10-01

    Volatiles are frequently abused as inhalants. The methods used for identification are generally nonspecific if analyzed concurrently with ethanol or require an additional analytical procedure that employs mass spectrometry. A previously published technique utilizing a capillary flow technology splitter to simultaneously quantitate and confirm ethyl alcohol by flame ionization and mass spectrometric detection after headspace sampling and gas chromatographic separation was evaluated for the detection of inhalants. Methanol, isopropanol, acetone, acetaldehyde, toluene, methyl ethyl ketone, isoamyl alcohol, isobutyl alcohol, n-butyl alcohol, 1,1-difluoroethane, 1,1,1-trifluoroethane, 1,1,1,2-tetrafluoroethane (Norflurane, HFC-134a), chloroethane, trichlorofluoromethane (Freon®-11), dichlorodifluoromethane (Freon®-12), dichlorofluoromethane (Freon®-21), chlorodifluoromethane (Freon®-22) and 1,2-dichlorotetrafluoroethane (Freon®-114) were validated for qualitative identification by this method. The validation for qualitative identification included evaluation of matrix effects, sensitivity, carryover, specificity, repeatability and ruggedness/robustness.

  14. Mass spectrometric isotope dilution analyses of palladium, silver, cadmium and tellurium in carbonaceous chondrites

    International Nuclear Information System (INIS)

    Loss, R.D.; Rosman, K.J.R.; De Laeter, J.

    1984-01-01

    The mass spectrometric isotope dilution technique was used to measure the elemental abundances of Pd, Ag, Cd and Te in Orgueil (C1), Ivuna (C1), Murray (C2) and Allende (C3) chondrites. The Pd abundance of 554 ppb for the Cl chondrites is almost identical to the recommended value of Anders and Ebihara (1982); that for Cd (712 ppb) is approximately 5% higher, whereas that for Ag (198 ppb) is approximately 10% lower than the recommended values. A smooth distribution for the abundances of the odd-A nuclides between 65 128 Te and 130 Te to lie approximately 30% above the r-process peak at A = 130, whereas the new value fits smoothly into the general trend. (author)

  15. Spectrometric gamma radiation of shale cores applied to sweet spot discrimination in Eastern Pomerania, Poland

    Science.gov (United States)

    Skupio, Rafal; de Alemar Barberes, Gabriel

    2017-12-01

    This paper describes the application and calculation of hydrocarbon anomalies in two different boreholes located in Eastern Pomerania (northern Poland). Spectrometric data from borehole geophysical probe (borehole 1) and portable gamma logger (borehole 2) were used to analyze shale formations. The results from borehole 1 presented a statistically significant, moderate correlation between calculated hydrocarbon anomalies and hydrocarbon saturation data obtained from well log interpretation. Borehole 2 has been analyzed focusing on the gamma radiation of the core samples, and the positive results of borehole 1. Hydrocarbon anomalies calculated from spectral gamma radiation are reliable indicators of sweet spots, based solely on a cursory evaluation of core measurements. These preliminary information acquired from gamma-ray measurements could help increase sampling precision of further geochemical analysis.

  16. A superheterodyne spectrometer for electronic paramagnetic. Resonance; Spectrometre superheterodyne de resonance paramagnetique electronique

    Energy Technology Data Exchange (ETDEWEB)

    Laffon, J L [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1963-12-15

    After a few generalities about electron paramagnetic resonance, a consideration of different experimental techniques authorises the choice of a particular type of apparatus. An EPR superheterodyne spectrometer built in the laboratory and having a novel circuit is described in detail. With this apparatus, many experimental results have been obtained and some of these are described as example. (author) [French] Apres quelques generalites sur le phenomene de resonance paramagnetique electronique, une synthese des differentes techniques experimentales, permet de fixer le choix d'un type d'appareillage. Un spectrometre de RPE superheterodyne realise en laboratoire et comportant un circuit original est expose dans le detail. Cet appareil a permis de nombreux resultats experimentaux dont quelques-uns sont decrits a titre d'exemple. (auteur)

  17. Levelling Airborne and Ground Gamma-Ray Spectrometric Data to Assist Uranium Exploration

    Energy Technology Data Exchange (ETDEWEB)

    Matolin, M., E-mail: matolin@natur.cuni.cz [Charles University, Prague (Czech Republic); Minty, B. [Geoscience Australia, Canberra (Australia)

    2014-05-15

    Geophysical methods can be used for mapping in both 2 and 3 dimensions, as well as the direct detection of ore bodies. The gamma-ray spectrometric method is an efficient method for the regional assessment of uranium potential and the detection of surface mineralization. However, the full potential of the method can only be realized when the data are adequately standardized. Examples of this standardization at both regional and local scales are dealt in this paper. At a regional scale, it is shown how the levelling of airborne gamma-ray spectrometry data over Australia increases the value of the resulting data, and on a local scale a geometrical correction for ground gamma-ray spectrometry in shallow holes that improves the accuracy of measurements is introduced. (author)

  18. Standard test methods for chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of uranium hexafluoride

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    1.1 These test methods cover procedures for subsampling and for chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of uranium hexafluoride UF6. Most of these test methods are in routine use to determine conformance to UF6 specifications in the Enrichment and Conversion Facilities. 1.2 The analytical procedures in this document appear in the following order: Note 1—Subcommittee C26.05 will confer with C26.02 concerning the renumbered section in Test Methods C761 to determine how concerns with renumbering these sections, as analytical methods are replaced with stand-alone analytical methods, are best addressed in subsequent publications. Sections Subsampling of Uranium Hexafluoride 7 - 10 Gravimetric Determination of Uranium 11 - 19 Titrimetric Determination of Uranium 20 Preparation of High-Purity U3O 8 21 Isotopic Analysis 22 Isotopic Analysis by Double-Standard Mass-Spectrometer Method 23 - 29 Determination of Hydrocarbons, Chlorocarbons, and Partially Substitut...

  19. Characterisation of radioactive contaminated materials by combined radiometric and spectrometric methods

    International Nuclear Information System (INIS)

    Dulama, C.; Toma, A.; Dobrin, R.; Ciocîrlan, C.; Stoica, S.; Valeca, M.; Popescu, I. I.

    2013-01-01

    In the present paper, a combined analytical methodology is described, for characterization of radioactive contaminated materials. The subject of testing activities was a set of solutions provided by the Cernavoda NPP, which are originating from processes of radiological survey of workplaces in the plant. In the introduction section, a theoretical approach was given to the origin and nature of main radionuclides occurring in the primary cooling system of the nuclear power plant, with the aim to establish selection criteria and performance requirements for the analytical methods to be used in the development of the characterization methodology. A combination of radiometric and spectrometric methods was selected, based on gross beta counting, high resolution gamma-ray spectrometry and liquid scintillation counting. (authors)

  20. Mass spectrometric 230Th-234U-238U dating of the Devils Hole calcite vein

    International Nuclear Information System (INIS)

    Ludwig, K.R.; Simmons, K.R.; Szabo, B.J.; Riggs, A.C.; Winograd, I.J.; Landwehr, J.M.; Hoffman, R.J.

    1992-01-01

    The Devils Hole calcite vein contains a long-term climatic record, but requires accurate chronologic control for its interpretation. Mass-spectrometric U-series ages for samples from core DH-11 yielding 230 Th ages with precisions ranging from less than 1,000 years (2σ) for samples younger than ∼140 ka (thousands of years ago) to less than 50,000 years for the oldest samples (∼566 ka). The 234 U/ 238 U ages could be determined to a precision of ∼20,000 years for all ages. Calcite accumulated continuously from 566 ka until ∼60 ka at an average rate of 0.7 millimeter per 10 3 years. The precise agreement between replicate analyses and the concordance of the 230 Th/ 238 U and 234 U/ 238 U ages for the oldest samples indicate that the DH-11 samples were closed systems and validate the dating technique in general

  1. Separation Techniques for Uranium and Plutonium at Trace Levels for the Thermal Ionization Mass Spectrometric Determination

    Energy Technology Data Exchange (ETDEWEB)

    Suh, M. Y.; Han, S. H.; Kim, J. G.; Park, Y. J.; Kim, W. H

    2005-12-15

    This report describes the state of the art and the progress of the chemical separation and purification techniques required for the thermal ionization mass spectrometric determination of uranium and plutonium in environmental samples at trace or ultratrace levels. Various techniques, such as precipitation, solvent extraction, extraction chromatography, and ion exchange chromatography, for separation of uranium and plutonium were evaluated. Sample preparation methods and dissolution techniques for environmental samples were also discussed. Especially, both extraction chromatographic and anion exchange chromatographic procedures for uranium and plutonium in environmental samples, such as soil, sediment, plant, seawater, urine, and bone ash were reviewed in detail in order to propose some suitable methods for the separation and purification of uranium and plutonium from the safeguards environmental or swipe samples. A survey of the IAEA strengthened safeguards system, the clean room facility of IAEA's NWAL(Network of Analytical Laboratories), and the analytical techniques for safeguards environmental samples was also discussed here.

  2. A contribution of airborne magnetic, gamma ray spectrometric data in understanding the structure of the Central Jebilet Hercynian massif and implications for mining

    Science.gov (United States)

    Maacha, Lhou; Jaffal, Mohammed; Jarni, Abdelmajid; Kchikach, Azzouz; Mouguina, El Mostafa; Zouhair, Mohamed; Ennaciri, Aomar; Saddiqi, Omar

    2017-10-01

    The Central Jebilet massif, well-known for its mining potential, has been explored for several years by the Managem Group, in collaboration with the National Office of Hydrocarbons and Mines (ONHYM), Morocco. This massif was surveyed by high-resolution magnetic and gamma-ray spectrometric methods in 1997 as part of a broader exploration program. In order to better exploit the results of this survey in understanding the structure of the Central Jebilet massif, we performed a series of processing of the collected data. The qualitative interpretation of this data highlighted the various magnetic domains, structures (e.g., lineaments and faults), and mafic intrusions. Euler deconvolution calculations provided estimates of the spatial location and depth of the magnetic sources, and spectral analysis of the magnetic data allowed further refinement of these depth estimates. Quantitative interpretation of some anomalies associated with exposed gossans allowed the characterization of their causative bodies, inferred to be sulfide deposits. The magnetic character of both the potential massive-sulfide bodies and the basic magmatic rocks (gabbro) were determined by the aeromagnetic data. Gamma ray spectrometric data has helped facilitate lithological discrimination and alteration zones, based on the radio-elemental distribution in the area. For example, the Thorium to Potassium ratio (Th/K) was used to highlight potassic alteration zones associated with massive-sulfide deposits in the Central Jebilet. The combined magnetic and radiometric study reveals the magnetic character of the Central Jebilet gossans, due to the content of pyrrhotite, which along with potassic alterations, has been recognized in all the known deposits of the Marrakech region. The results of this geophysical campaign supplement the existing geological and structural maps of Central Jebilet massif.

  3. GNU polyxmass: a software framework for mass spectrometric simulations of linear (bio-polymeric analytes

    Directory of Open Access Journals (Sweden)

    Rusconi Filippo

    2006-04-01

    Full Text Available Abstract Background Nowadays, a variety of (bio-polymers can be analyzed by mass spectrometry. The detailed interpretation of the spectra requires a huge number of "hypothesis cycles", comprising the following three actions 1 put forth a structural hypothesis, 2 test it, 3 (invalidate it. This time-consuming and painstaking data scrutiny is alleviated by using specialized software tools. However, all the software tools available to date are polymer chemistry-specific. This imposes a heavy overhead to researchers who do mass spectrometry on a variety of (bio-polymers, as each polymer type will require a different software tool to perform data simulations and analyses. We developed a software to address the lack of an integrated software framework able to deal with different polymer chemistries. Results The GNU polyxmass software framework performs common (bio-chemical simulations–along with simultaneous mass spectrometric calculations–for any kind of linear bio-polymeric analyte (DNA, RNA, saccharides or proteins. The framework is organized into three modules, all accessible from one single binary program. The modules let the user to 1 define brand new polymer chemistries, 2 perform quick mass calculations using a desktop calculator paradigm, 3 graphically edit polymer sequences and perform (bio-chemical/mass spectrometric simulations. Any aspect of the mass calculations, polymer chemistry reactions or graphical polymer sequence editing is configurable. Conclusion The scientist who uses mass spectrometry to characterize (bio-polymeric analytes of different chemistries is provided with a single software framework for his data prediction/analysis needs, whatever the polymer chemistry being involved.

  4. Increased Protein Structural Resolution from Diethylpyrocarbonate-based Covalent Labeling and Mass Spectrometric Detection

    Science.gov (United States)

    Zhou, Yuping; Vachet, Richard W.

    2012-04-01

    Covalent labeling and mass spectrometry are seeing increased use together as a way to obtain insight into the 3-dimensional structure of proteins and protein complexes. Several amino acid specific (e.g., diethylpyrocarbonate) and non-specific (e.g., hydroxyl radicals) labeling reagents are available for this purpose. Diethylpyrocarbonate (DEPC) is a promising labeling reagent because it can potentially probe up to 30% of the residues in the average protein and gives only one reaction product, thereby facilitating mass spectrometric analysis. It was recently reported, though, that DEPC modifications are labile for some amino acids. Here, we show that label loss is more significant and widespread than previously thought, especially for Ser, Thr, Tyr, and His residues, when relatively long protein digestion times are used. Such label loss ultimately decreases the amount of protein structural information that is obtainable with this reagent. We find, however, that the number of DEPC modified residues and, thus, protein structural information, can be significantly increased by decreasing the time between the covalent labeling reaction and the mass spectrometric analysis. This is most effectively accomplished using short (e.g., 2 h) proteolytic digestions with enzymes such as immobilized chymotrypsin or Glu-C rather than using methods (e.g., microwave or ultrasonic irradiation) that accelerate proteolysis in other ways. Using short digestion times, we show that the percentage of solvent accessible residues that can be modified by DEPC increases from 44% to 67% for cytochrome c, 35% to 81% for myoglobin, and 76% to 95% for β-2-microglobulin. In effect, these increased numbers of modified residues improve the protein structural resolution available from this covalent labeling method. Compared with typical overnight digestion conditions, the short digestion times decrease the average distance between modified residues from 11 to 7 Å for myoglobin, 13 to 10 Å for

  5. Comparative Analysis of Volatile Defensive Secretions of Three Species of Pyrrhocoridae (Insecta: Heteroptera by Gas Chromatography-Mass Spectrometric Method.

    Directory of Open Access Journals (Sweden)

    Jan Krajicek

    Full Text Available The true bugs (Hemiptera: Heteroptera have evolved a system of well-developed scent glands that produce diverse and frequently strongly odorous compounds that act mainly as chemical protection against predators. A new method of non-lethal sampling with subsequent separation using gas chromatography with mass spectrometric detection was proposed for analysis of these volatile defensive secretions. Separation was performed on Rtx-200 column containing fluorinated polysiloxane stationary phase. Various mechanical irritation methods (ultrasonics, shaking, pressing bugs with plunger of syringe were tested for secretion sampling with a special focus on non-lethal irritation. The preconcentration step was performed by sorption on solid phase microextraction (SPME fibers with different polarity. For optimization of sampling procedure, Pyrrhocoris apterus was selected. The entire multi-parameter optimization procedure of secretion sampling was performed using response surface methodology. The irritation of bugs by pressing them with a plunger of syringe was shown to be the most suitable. The developed method was applied to analysis of secretions produced by adult males and females of Pyrrhocoris apterus, Pyrrhocoris tibialis and Scantius aegyptius (all Heteroptera: Pyrrhocoridae. The chemical composition of secretion, particularly that of alcohols, aldehydes and esters, is species-specific in all three pyrrhocorid species studied. The sexual dimorphism in occurrence of particular compounds is largely limited to alcohols and suggests their epigamic intraspecific function. The phenetic overall similarities in composition of secretion do not reflect either relationship of species or similarities in antipredatory color pattern. The similarities of secretions may be linked with antipredatory strategies. The proposed method requires only a few individuals which remain alive after the procedure. Thus secretions of a number of species including even the rare

  6. Determination of suvorexant in human plasma using 96-well liquid-liquid extraction and HPLC with tandem mass spectrometric detection.

    Science.gov (United States)

    Breidinger, S A; Simpson, R C; Mangin, E; Woolf, E J

    2015-10-01

    A method, using liquid chromatography with tandem mass spectrometric detection (LC-MS/MS), was developed for the determination of suvorexant (MK-4305, Belsomra(®)), a selective dual orexin receptor antagonist for the treatment insomnia, in human plasma over the concentration range of 1-1000ng/mL. Stable isotope labeled (13)C(2)H3-suvorexant was used as an internal standard. The sample preparation procedure utilized liquid-liquid extraction, in the 96-well format, of a 100μL plasma sample with methyl t-butyl ether. The compounds were chromatographed under isocratic conditions on a Waters dC18 (50×2.1mm, 3μm) column with a mobile phase consisting of 30/70 (v/v %) 10mM ammonium formate, pH3/acetonitrile at a flow rate of 0.3mL/min. Multiple reaction monitoring of the precursor-to-product ion pairs for suvorexant (m/z 451→186) and (13)C(2)H3-suvorexant (m/z 455→190) on an Applied Biosystems API 4000 tandem mass spectrometer was used for quantitation. Intraday assay precision, assessed in six different lots of control plasma, was within 10% CV at all concentrations, while assay accuracy ranged from 95.6 to 105.0% of nominal. Quality control (QC) samples in plasma were stored at -20°C. Initial within day analysis of QCs after one freeze-thaw cycle showed accuracy within 9.5% of nominal with precision (CV) of 6.7% or less. The plasma QC samples were demonstrated to be stable for up to 25 months at -20°C. The method described has been used to support clinical studies during Phase I through III of clinical development. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. A comparison of semiconductor gamma spectrometric analysis using the peak net area calculations and the whole spectrum processing

    International Nuclear Information System (INIS)

    Krnac, S.; Koskelo, M.; Venkatamaran, R.

    1998-01-01

    This study was conducted to compare the results of gamma spectrometric analysis using the Scaling Confirmatory Factor Analysis (SCFA) method to that of Genie2K, which uses a more traditional method. Gamma ray spectra had had been acquired for several gamma standard sources, all of which except Co-57 and Eu-152 being single gamma ray emitting nuclides. These standard sources spanned the energy range from 60 keV (Am-241) to 1116 keV (Zn-65). The standard sources were counted at 3 different geometries at 3 different geometries, with source-detector distances of 0, 5, and 15 cm. Using single gamma ray spectra collected at a given counting geometry, and the certificate file, an efficiency calibration was created for that geometry. Three different test spectra, one for each counting geometry, had been created by combining several of the standard source spectra. The efficiency calibrations created for the 3 geometries were loaded into the respective spectrum files. Each test spectrum was analyzed using the standard Genie2K engines; Peak locate, Peak search, Interactive peak fit, Background subs-traction, Efficiency correction, and Nuclide Identification with interference analysis. The results of the various calculation steps were reported. In all 3 test cases, the SCFA method identified all the nuclides correctly. The K-40 activities calculated by the SCFA method were reasonably close to that from Genie2K analysis. In general, the quantitative results of the SCFA method were impressive in all 3 cases. On a positive note, the SCFA method did identify low yield gamma lines in Eu-152, which were not identified by the Genie2K analysis. This substantiates claim that the SCFA is more sensitive than the traditional method of spectrum analysis. (authors)

  8. Non-Destructive X-ray Spectrometric and Chromatographic Analysis of Metal Containers and Their Contents, from Ancient Macedonia

    Directory of Open Access Journals (Sweden)

    Christos S. Katsifas

    2018-06-01

    Full Text Available This work describes a holistic archaeometric approach to ancient Macedonian specimens. In the region of the ancient city Lete, the deceased members of a rich and important family were interred in a cluster of seven tombs (4th century BC. Among the numerous grave goods, there was also a set of metal containers preserving their original content. The physico-chemical analysis of the containers and their contents was performed in order to understand the purpose of their use. For the containers, Energy Dispersive micro-X-Ray Fluorescence (EDμXRF spectroscopy was implemented taking advantage of its non-invasive character. The case (B35 and the small pyxis (B37 were made of a binary Cu-Sn alloy accompanied by a slight amount of impurities (Fe, Pb, As and the two miniature bowls were made of almost pure Cu. For the study of the contents, a combination of EDμXRF, X-Ray Diffraction (XRD, and Gas Chromatography—Mass Spectrometry (GC-MS was carried out. Especially for the extraction of the volatile compounds, the Solid Phase Micro-Extraction (SPME technique was used in the headspace mode. Because of the detection of Br, High Pressure Liquid Chromatography coupled to a Diode-Array-Detector (HPLC-DAD was implemented, confirming the existence of the ancient dye shellfish purple (porphyra in Greek. The analytical results of the combined implementation of spectrometric and chromatographic analytical techniques of the metal containers and their contents expand our knowledge about the pharmaceutical practices in Macedonia during the 4th century BC.

  9. Laser-induced spectrometric techniques to investigate the speciation of Eu in organic media

    International Nuclear Information System (INIS)

    Couston, L.; Roudil, D.; Charbonnel, M.Ch.; Delage, J.; Flandin, J.L.; Mesmin, C.; Rivasseau, C.

    2000-01-01

    Laser-induced spectrometric techniques provide both selectivity and sensitivity. The extremely low detection limits are ideal for assessing the extraction mechanisms involved in enhanced reprocessing applications through detailed speciation studies. Although time-resolved laser-induced fluorescence spectroscopy (TRLIF) is one of the most sensitive spectroscopy techniques, with the optical spectrum and its lifetime constituting two sources of data, it is limited to a few fluorescing actinides and lanthanides. This drawback warrants the development of an additional, complementary spectroscopic system with greater sensitivity than UV-Visible-near IR absorptiometry, based on measuring the pressure wave caused by the deexcitation of non-fluorescing species. Laser-induced photoacoustic spectroscopy (LIPAS) is based on measuring the characteristics of the pressure wave emitted during non-radiative relaxation of the absorbed energy. This speciation technique should allow investigation of compounds that absorb in the UV-visible range and are present at low concentrations in solution. It provides data on the nature and concentration of the species, including its oxidation, complexation and even colloidal states. The two techniques with a common laser source OPO were recently installed at Marcoule. TRLIF speciation studies are generally based on analyzing modifications in the fluorescence spectrum following a short laser pulse. They are related to the characteristic spectral pattern and relaxation rate of each species in solution. In the particular case of fluorescent decay of trivalent Am, Cm, Sm, Eu, Tb and Dy ions, the metallic cation deexcitation constant is closely related to the number of water molecules in the primary coordination sphere. This property helps to obtain more information on the structure around the metal ion. The first study was an investigation of the complexation of Eu(III) by TEMA (N, N'-tetra-ethyl-malonamide (C 2 H 5 ) 2 NCO-CH 2 CON(C 2 H 5 ) 2 ) in

  10. Study and construction of a {beta}-spectrometer of uniform axial magnetic field fitted with a {beta}-{gamma} coincidence selector. Study of the {beta} spectra of {sup 32}P, {sup 203}Hg, {sup 198}Au. Measurement of the conversion coefficients of {sup 203}Ti and of {sup 198}Hg; Etude et realisation d'un spectrometre-{beta} a champ magnetique axial uniforme, muni d'un selecteur de coincidence {beta}-{gamma}. Etude des spectres {beta} du {sup 32}p, {sup 203}Hg, {sup 198}Au. Mesure des coefficients de conversion du {sup 203}Ti et du {sup 198}Hg

    Energy Technology Data Exchange (ETDEWEB)

    Parsignault, D [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-06-01

    In the first part is given the principle of the beta spectrometer with uniform axial field using systematically the idea of caustics. The apparatus is described and its properties compared to those deduced from trajectory calculations. The {beta}-ray and {gamma}-ray detectors and the device for selecting coincidences with a 2 {tau} resolution of 5 nanoseconds are also presented. In the second part, the spectrometer is used for studying reference elements and the most accurate results are confirmed. The {beta} spectrum of {sup 60}Co has a statistical form with an accuracy of 1 per cent; the maximum energy E{sub 0} is 316.5 {+-} 1.5 keV. That of the 7/2 + {yields} 11/2 transition for {sup 137}Cs has a unique form, once forbidden. E{sub 0}= 522 {+-} 3 keV. Conversion coefficients {alpha}{sub k} = 96 {+-} 1 X 10{sup -3} {alpha}L + M + N = 20.9 {+-} 0.5 X 10{sup -3}. The two {beta} spectra of {sup 59}Fe, separated by coincidence with the gamma, have the statistical form E{sub 0} = 462 {+-} 2 keV (55.1 + 0,3 per cent) and E{sub 1} = 275 {+-} 4 keV (44.9 {+-} 0.3 per cent). It is then verified whether the l selection rule is apparent in the shape of the phosphorus 32 beta spectrum. It is found in fact that it is not of statistical shape and its shape coefficient is determined. For a theoretical interpretation it is necessary to have better approximations than those generally used and this interpretation will not be unique. This work has also made it possible to show that the source contains a small proportion of {sup 33}P. The study of the {sup 203}Hg {beta} spectrum followed by the 279 keV gamma spectrum is designed to determine the conversion coefficients. The interior spectrum of gold 198 is not of statistical shape either. The form coefficient is determined together with the conversion coefficients which are in slight disagreement with those calculated by Rose or Sliv. An interpretation of the spectrum is put forward which proposes an imperfect compensation for the

  11. Study and construction of a {beta}-spectrometer of uniform axial magnetic field fitted with a {beta}-{gamma} coincidence selector. Study of the {beta} spectra of {sup 32}P, {sup 203}Hg, {sup 198}Au. Measurement of the conversion coefficients of {sup 203}Ti and of {sup 198}Hg; Etude et realisation d'un spectrometre-{beta} a champ magnetique axial uniforme, muni d'un selecteur de coincidence {beta}-{gamma}. Etude des spectres {beta} du {sup 32}p, {sup 203}Hg, {sup 198}Au. Mesure des coefficients de conversion du {sup 203}Ti et du {sup 198}Hg

    Energy Technology Data Exchange (ETDEWEB)

    Parsignault, D. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-06-01

    In the first part is given the principle of the beta spectrometer with uniform axial field using systematically the idea of caustics. The apparatus is described and its properties compared to those deduced from trajectory calculations. The {beta}-ray and {gamma}-ray detectors and the device for selecting coincidences with a 2 {tau} resolution of 5 nanoseconds are also presented. In the second part, the spectrometer is used for studying reference elements and the most accurate results are confirmed. The {beta} spectrum of {sup 60}Co has a statistical form with an accuracy of 1 per cent; the maximum energy E{sub 0} is 316.5 {+-} 1.5 keV. That of the 7/2 + {yields} 11/2 transition for {sup 137}Cs has a unique form, once forbidden. E{sub 0}= 522 {+-} 3 keV. Conversion coefficients {alpha}{sub k} = 96 {+-} 1 X 10{sup -3} {alpha}L + M + N = 20.9 {+-} 0.5 X 10{sup -3}. The two {beta} spectra of {sup 59}Fe, separated by coincidence with the gamma, have the statistical form E{sub 0} = 462 {+-} 2 keV (55.1 + 0,3 per cent) and E{sub 1} = 275 {+-} 4 keV (44.9 {+-} 0.3 per cent). It is then verified whether the l selection rule is apparent in the shape of the phosphorus 32 beta spectrum. It is found in fact that it is not of statistical shape and its shape coefficient is determined. For a theoretical interpretation it is necessary to have better approximations than those generally used and this interpretation will not be unique. This work has also made it possible to show that the source contains a small proportion of {sup 33}P. The study of the {sup 203}Hg {beta} spectrum followed by the 279 keV gamma spectrum is designed to determine the conversion coefficients. The interior spectrum of gold 198 is not of statistical shape either. The form coefficient is determined together with the conversion coefficients which are in slight disagreement with those calculated by Rose or Sliv. An interpretation of the spectrum is put forward which proposes an imperfect compensation for the

  12. In situ gamma-ray spectrometric analysis of radionuclide distributions at a commercial shallow land burial site

    International Nuclear Information System (INIS)

    Kirby, L.J.; Campbell, R.M.

    1984-10-01

    Gamma-ray spectrometric analysis conducted at the Maxey Flats, Kentucky (USA) shallow land burial site confirmed that the waste radionuclides have been retained largely within the restricted area of the burial site. Concentrations of 137 Cs and 60 Co were comparable with those originating from global fallout and lower than concentrations measured in several other areas having similar rainfall. In-situ spectrometric analyses, corroborated by soil sample and vegetation analyses, indicate that the site has influenced 60 Co levels slightly in the west drainage channel, but 137 Cs did not originate from the site. Concentrations of 60 Co, 90 Sr and 137 Cs determined in subsurface soils by well logging techniques confirmed that subsurface migration of waste-derived radionuclides to points outside the restricted area has not been a significant source of contamination of the environs adjacent to the site. 8 references, 8 figures

  13. Standard test methods for chemical and mass spectrometric analysis of nuclear-grade gadolinium oxide (Gd2O3) powder

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2006-01-01

    1.1 These test methods cover procedures for the chemical and mass spectrometric analysis of nuclear-grade gadolinium oxide powders to determine compliance with specifications. 1.2 The analytical procedures appear in the following order: Sections Carbon by Direct CombustionThermal Conductivity C1408 Test Method for Carbon (Total) in Uranium Oxide Powders and Pellets By Direct Combustion-Infrared Detection Method Total Chlorine and Fluorine by Pyrohydrolysis Ion Selective Electrode C1502 Test Method for Determination of Total Chlorine and Fluorine in Uranium Dioxide and Gadolinium Oxide Loss of Weight on Ignition 7-13 Sulfur by CombustionIodometric Titration Impurity Elements by a Spark-Source Mass Spectrographic C761 Test Methods for Chemical, Mass Spectrometric, Spectrochemical,Nuclear, and Radiochemical Analysis of Uranium Hexafluoride C1287 Test Method for Determination of Impurities In Uranium Dioxide By Inductively Coupled Plasma Mass Spectrometry Gadolinium Content in Gadolinium Oxid...

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

    International Nuclear Information System (INIS)

    Gil, Raúl A.; Pacheco, Pablo H.; Cerutti, Soledad; Martinez, Luis D.

    2015-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-05-22

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

  16. Targeted selected reaction monitoring mass spectrometric immunoassay for insulin-like growth factor 1.

    Directory of Open Access Journals (Sweden)

    Eric E Niederkofler

    Full Text Available Insulin-like growth factor 1 (IGF1 is an important biomarker of human growth disorders that is routinely analyzed in clinical laboratories. Mass spectrometry-based workflows offer a viable alternative to standard IGF1 immunoassays, which utilize various pre-analytical preparation strategies. In this work we developed an assay that incorporates a novel sample preparation method for dissociating IGF1 from its binding proteins. The workflow also includes an immunoaffinity step using antibody-derivatized pipette tips, followed by elution, trypsin digestion, and LC-MS/MS separation and detection of the signature peptides in a selected reaction monitoring (SRM mode. The resulting quantitative mass spectrometric immunoassay (MSIA exhibited good linearity in the range of 1 to 1,500 ng/mL IGF1, intra- and inter-assay precision with CVs of less than 10%, and lowest limits of detection of 1 ng/mL. The linearity and recovery characteristics of the assay were also established, and the new method compared to a commercially available immunoassay using a large cohort of human serum samples. The IGF1 SRM MSIA is well suited for use in clinical laboratories.

  17. A spectrometrical method to measure the deuterium content in 2H-enriched water

    International Nuclear Information System (INIS)

    Dumke, I.

    1980-04-01

    A test method and spectrometer has been developed for emission-spectrometrical measurement of the deuterium content in water enriched with deuterium. The water sample is melted into a previously evacuated glas tube and a gas discharge is excited in vapour over the cooled sample to adjust to a low vapour pressure with high frequency. The intensities of the H(α) and D(α) lines appearing in the spectrum determine the D-content. Both lines were resolved by a Fabry-Perot interferometer and geometrically separated fed to two photodetectors. The remaining spectrum is filtered off. Following electronic calculation of the signals, the measured value is indicated which has to be corrected by a standard curve. The relative measuring accuracy is about +-1% for enrichments of over 1% D and less than +-5% in the region of 0.3-1% D. The detection limit is about 0.03% D (sample amount: 50 μl, average of 5 samples). (orig./HP) [de

  18. Atomic absorption spectrometric determination of copper, zinc, and lead in geological materials

    Science.gov (United States)

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

    1976-01-01

    An atomic absorption spectrometric method is described for the determination of copper, zinc, and lead in geological materials. The sample is digested with HF-HCl-H2O2; the final solution for analysis is in 10 % (v/v) HCl. Copper and zinc are determined directly by aspirating the solution into an air-acetylene flame. A separate aliquot of the solution is used for determination of lead; lead is extracted into TOPO-MIBK from the acidic solution in the presence of iodide and ascorbic acid. For a 0.50-g sample, the limits of determination are 10-2000 p.p.m. for Cu and Zn, and 5-5000 p.p.m. for Pb. As much as 40 % Fe or Ca. and 10 % Al, Mg, or Mn in the sample do not interfere. The proposed method can be applied to the determination of copper, zinc, and lead in a wide range of geological materials including iron- and manganese-rich, calcareous and carbonate samples. ?? 1976.

  19. Liquid chromatography/mass spectrometric determination of patulin in apple juice using atmospheric pressure photoionization.

    Science.gov (United States)

    Takino, Masahiko; Daishima, Shigeki; Nakahara, Taketoshi

    2003-01-01

    This paper describes a comparison between atmospheric pressure chemical ionization (APCI) and the recently introduced atmospheric pressure photoionization (APPI) technique for the liquid chromatography/mass spectrometric (LC/MS) determination of patulin in clear apple juice. A column switching technique for on-line extraction of clear apple juice was developed. The parameters investigated for the optimization of APPI were the ion source parameters fragmentor voltage, capillary voltage, and vaporizer temperature, and also mobile phase composition and flow rate. Furthermore, chemical noise and signal suppression of analyte signals due to sample matrix interference were investigated for both APCI and APPI. The results indicated that APPI provides lower chemical noise and signal suppression in comparison with APCI. The linear range for patulin in apple juice (correlation coefficient >0.999) was 0.2-100 ng mL(-1). Mean recoveries of patulin in three apple juices ranged from 94.5 to 103.2%, and the limit of detection (S/N = 3), repeatability and reproducibility were 1.03-1.50 ng mL(-1), 3.9-5.1% and 7.3-8.2%, respectively. The total analysis time was 10.0 min. Copyright 2003 John Wiley & Sons, Ltd.

  20. Quantum dots assisted laser desorption/ionization mass spectrometric detection of carbohydrates: qualitative and quantitative analysis.

    Science.gov (United States)

    Bibi, Aisha; Ju, Huangxian

    2016-04-01

    A quantum dots (QDs) assisted laser desorption/ionization mass spectrometric (QDA-LDI-MS) strategy was proposed for qualitative and quantitative analysis of a series of carbohydrates. The adsorption of carbohydrates on the modified surface of different QDs as the matrices depended mainly on the formation of hydrogen bonding, which led to higher MS intensity than those with conventional organic matrix. The effects of QDs concentration and sample preparation method were explored for improving the selective ionization process and the detection sensitivity. The proposed approach offered a new dimension to the application of QDs as matrices for MALDI-MS research of carbohydrates. It could be used for quantitative measurement of glucose concentration in human serum with good performance. The QDs served as a matrix showed the advantages of low background, higher sensitivity, convenient sample preparation and excellent stability under vacuum. The QDs assisted LDI-MS approach has promising application to the analysis of carbohydrates in complex biological samples. Copyright © 2016 John Wiley & Sons, Ltd.

  1. Radiometric and spectrometric analysis of boron-containing rocks in boreholes

    International Nuclear Information System (INIS)

    Vakhtin, B.S.; Ivanov, V.S.; Semenov, V.I.

    1973-01-01

    Gamma-logging, neutron-gamma logging and neutron-resonance logging were carried out when exploring the boron-containing wells. Spectrometry of natural and capture gamma-radiation, of the induced radioactivity was performed in particular points of the wells. Continuous measurements were done with the PRKS-2 logging radiometer, spectrometric measurements - with a simulator of a well rig of 130 mm outer dia. (NaI crystal, 63x63 mm) and the AI-128 pulse analyzer. The time of getting gamma-logging spectra is 16 min, that of neutron-gamma logging is 8 min. When measuring the induced radioactivity, the time of activation is 35 min., the time-out - 1 min., the time of measurement measurement - 32 min.; the neutron gamma- logging probe is 35 cm long, the probe used in activation measurements is 2 cm long. It has been observed that porphyrites and garnetiferous rocks are distinguished by elevated readings on the gamma-logging and neutron-resonance logging curves, whereas boron-containing rocks - by lowered readings in neutron-gamma logging and neutron-resonance logging. In the gamma-logging spectra the lines of uranium-radium, potassium and thorium are observed, in neutron-gamma logging spectra - the lines of silicon, calcium and hydrogen, in the induced radioactivity spectra - Al 28 and Mn 56

  2. Vaporization of niobium dioxide by mass-effusion and mass-spectrometric methods

    International Nuclear Information System (INIS)

    Kamegashira, N.; Matsui, T.; Harada, M.; Naito, K.

    1981-01-01

    The congruence of the vaporization process of NbO, NbO 2 , Nb 12 O 29 and Nb 2 O 5 in the niobium-oxygen system was investigated from the phase change of the solid residue after vaporization, and it was observed that only the NbO 2 phase vaporizes congruently. The vapor pressures over NbO 2 (s) were measured by means of a combination of mass-effusion (weight loss measurement) and mass-spectrometric methods in the temperature range 1953-2323 K. By applying the second and the third law treatments of thermodynamics to the partial pressures of the gaseous species NbO 2 (g), NbO(g) and O(g), the enthalpies of vaporization for the reactions NbO 2 (s,1)=NbO 2 (g) and NbO 2 (s,1)=NbO(g)+O(g), were calculated. From these data the enthalpies of formation and the dissociation energies of NbO 2 (g) and NbO(g) were also determined. The uncertainties included in the third law treatment were discussed, and the results calculated by the third law treatment using the most reliable data available at present were presented. (orig.)

  3. Standard methods for chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of uranium hexafluoride

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    All methods described for subsampling and analysis of UF 6 are in routine use at United States Atomic Energy Commission installations. A gravimetric method is included for U and titrimetric methods, for Cl 2 and U. Mass spectrometric methods are given for both double and single standard procedures for U-isotopic content and for semiquantitative determination of hydrocarbons, chlorocarbons, and partially substituted halohydrocarbons. Spectroscopic methods are described for 232 U, fission products, Pu, and Np. In some instances an ion exchange- or extraction-separation is specified prior to the spectroscopic determination. Mass spectroscopic procedures for 31 trace elements are included, as are spectrophotometric methods for Br 2 , Si, P, Ti, V, W, Th, and Mo. Following a preliminary separation for some elements, emission spectroscopic procedures are described for B, Si, Ru, Hf, Mo, Nb, Ta, Ti, W, Zr, V, Th, rare earths, and other elements. Procedures for the determination of Sb, Ru, Al, Cd, Co, Ca, Cr, Fe, Pb, Mg, Mn, Ni, K, Na, and Zn by atomic absorption methods are included. The preparation of high-purity U 3 O 8 by the hydrolysis of UF 6 to UO 2 F 2 which upon drying and pyrohydrolysis yields U 3 O 8 is described

  4. Column preconcentration and electrothermal atomic absorption spectrometric determination of rhodium in some food and standard samples.

    Science.gov (United States)

    Taher, Mohammad Ali; Pourmohammad, Fatemeh; Fazelirad, Hamid

    2015-12-01

    In the present work, an electrothermal atomic absorption spectrometric method has been developed for the determination of ultra-trace amounts of rhodium after adsorption of its 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol/tetraphenylborate ion associated complex at the surface of alumina. Several factors affecting the extraction efficiency such as the pH, type of eluent, sample and eluent flow rates, sorption capacity of alumina and sample volume were investigated and optimized. The relative standard deviation for eight measurements of 0.1 ng/mL of rhodium was ±6.3%. In this method, the detection limit was 0.003 ng/mL in the original solution. The sorption capacity of alumina and the linear range for Rh(III) were evaluated as 0.8 mg/g and 0.015-0.45 ng/mL in the original solution, respectively. The proposed method was successfully applied for the extraction and determination of rhodium content in some food and standard samples with high recovery values. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Synoptic view of the different domains of application of airborne radiometric and spectrometric surveys in egypt

    International Nuclear Information System (INIS)

    Fouad, K.M.

    1998-01-01

    Airborne radiometric survey has been applied for more than three decades in egypt. Experience gained from the acquired data over different geological environments has revealed the importance of this geophysical tool in: 1. disclosure of anomalies of potential uranium deposits, 2. geological mapping, 3. environmental monitoring of natural radiometric background around nuclear facilities, as well as the detection of nuclear fallout resulting from local or foreign nuclear activities. The advent of recording of the discriminated gamma ray energies in the airborne 256-channel spectrometer has eventually resulted in the quantitative detection of uranium, thorium, and potassium and their elemental ratios in the rocks. This has greatly widened the scope of geophysical and geochemical application. When this type is coupled with airborne magnetometry, the geological and structural configuration is appreciably revealed in three dimensions. The important role played by the statistical method of analysis is also shown. Case histories from the eastern desert, and sinai peninsula, are exhibited to help manifest the wide variety of applications of radiometric and spectrometric surveys

  6. Analysis of Endocrine Disrupting Pesticides by Capillary GC with Mass Spectrometric Detection

    Directory of Open Access Journals (Sweden)

    Svetlana Hrouzková

    2012-09-01

    Full Text Available Endocrine disrupting chemicals, among them many pesticides, alter the normal functioning of the endocrine system of both wildlife and humans at very low concentration levels. Therefore, the importance of method development for their analysis in food and the environment is increasing. This also covers contributions in the field of ultra-trace analysis of multicomponent mixtures of organic pollutants in complex matrices. With this fact conventional capillary gas chromatography (CGC and fast CGC with mass spectrometric detection (MS has acquired a real importance in the analysis of endocrine disrupting pesticide (EDP residues. This paper provides an overview of GC methods, including sample preparation steps, for analysis of EDPs in a variety of matrices at ultra-trace concentration levels. Emphasis is put on separation method, mode of MS detection and ionization and obtained limits of detection and quantification. Analysis time is one of the most important aspects that should be considered in the choice of analytical methods for routine analysis. Therefore, the benefits of developed fast GC methods are important.

  7. Mass Spectrometric Identification and Differentiation of Botulinum Neurotoxins through Toxin Proteomics.

    Science.gov (United States)

    Kalb, Suzanne R; Barr, John R

    2013-08-01

    Botulinum neurotoxins (BoNTs) cause the disease botulism, which can be lethal if untreated. There are seven known serotypes of BoNT, A-G, defined by their response to antisera. Many serotypes are distinguished into differing subtypes based on amino acid sequence and immunogenic properties, and some subtypes are further differentiated into toxin variants. Toxin characterization is important as different types of BoNT can respond differently to medical countermeasures for botulism, and characterization of the toxin can aid in epidemiologic and forensic investigations. Proteomic techniques have been established to determine the serotype, subtype, or toxin variant of BoNT. These techniques involve digestion of the toxin into peptides, tandem mass spectrometric (MS/MS) analysis of the peptides, and database searching to identify the BoNT protein. These techniques demonstrate the capability to detect BoNT and its neurotoxin-associated proteins, and differentiate the toxin from other toxins which are up to 99.9% identical in some cases. This differentiation can be accomplished from toxins present in a complex matrix such as stool, food, or bacterial cultures and no DNA is required.

  8. A mass spectrometric study of the neutral and ionic vapor components of ytterbium chlorides; formation enthalpies of YbCl2 and YbCl3 molecules, and YbCl3- and YbCl4- ions in the gas phase

    International Nuclear Information System (INIS)

    Kuznetsov, F.Yh.; Kudin, L.S.; Pogrebnoj, A.M.; Butman, M.F.; Burdukovskaya, G.G.

    1997-01-01

    Ionic and neutral components of saturated vapour over the ytterbium di-and trichloride is studied through the Knudsen effusive method with mass-spectromic registration of evaporated products within the temperature range of 1000-1300 K. It is found that ytterbium trichloride is subjected to thermal decomposition with formation of ytterbium dichloride and molecular chloride. Sublimation enthalpy and enthalpy of YbCl 2 and YbCl 3 molecules formation in a gaseous phase at 298 K, comprising 356±6, 293±8, -425±6 and -667±6 kJ/mole correspondingly, are determined with application of 2 and 3 thermodynamical laws. Enthalpies of YbCl 3 - and YbCl 4 - negative ions formation in a gaseous phase at 298 K equal to -895 and -1211±30 kJ/mole correspondingly are calculated by measured equilibrium constants ion-molecular reaction. 30 refs., 3 figs., 3 tabs

  9. Optimisation of the muon spectrometer from the detector ALICE used for the study of the quark and gluon plasma at LHC; Optimisation du spectrometre a muons du detecteur ALICE pour l'etude du plasma de quarks et de gluons au LHC

    Energy Technology Data Exchange (ETDEWEB)

    Guernane, R

    2001-01-01

    The ALICE experiment performed at the LHC will establish and study the phase transition from hadronic matter to a matter to a state of deconfined partons called Quark Gluon Plasma (QGP). The suppression of heavy flavour resonances (J{phi},{gamma}) is the most promising probe for diagnosing the formation and early stages of the QGP in ultrarelativistic heavy ion collisions. The complete spectrum of heavy quarkonia resonances, i.e. J/{phi}, {phi}', {gamma}, {gamma}' and {phi}' will be measured via their muonic decay in a forward spectrometer with a mass resolution sufficient to separate all states. It is composed of five tracking stations, each consisting of two Cathode Pad Chambers (CPC). In this work, we developed a prototype of CPC having the original feature of parallel charge read out from one segmented cathode. The geometry and operating parameters have been optimized for station 3. The expected multi-hit rate and multi-hit deconvolution have been evaluated with a complete detailed simulation and an efficient method to disentangle close hits has been proposed. The magnetic field effect on the intrinsic spatial resolution of the chambers has also been estimated. The simulated performance of the CPC's is confirmed by beam-test results obtained at CERN with prototypes. The measurement of dimuons is expected to be contaminated by beam-related background. The rate of beam-gas interactions is several orders of magnitude larger than the signal rate for p-p collisions which is the reference for further studies of p-A and A-A collisions. The ALICE Collaboration decided to equip the muon spectrometer with a level 0 trigger counter (V0) in order to validate the dimuon trigger signal in p-p mode. The various steps involved in designing the V0 scintillator hodoscope are presented in this thesis. (author)

  10. Gamow-Teller decay and nuclear deformation: implementing of a new total absorption spectrometer, study of isotopes N {approx_equal} Z krypton and strontium; Decroissance Gamow-Teller et deformation nucleaire: mise en oeuvre d'un nouveau spectrometre a absorption totale, etude d'isotopes N {approx_equal} Z de krypton et strontium

    Energy Technology Data Exchange (ETDEWEB)

    Poirier, E

    2002-12-01

    Nuclei with A {approx} 70 along the N=Z line are known to be the scene of phenomena closely related to the nuclear deformation and are of particular interest since theoretical mean field calculations predict that a large part of the Gamow-Teller resonance might be located below the ground state of the mother nucleus and then be accessible through {beta}-decay studies. These results have shown the effect of the shape of the ground state on the intensity of the Gamow-Teller strength. Thus, the experimental determination, through {delta}-decay, of the Gamow-Teller strength distribution and the comparison to the theoretical predictions allow to pin down the quadrupolar deformation parameter of the ground state of the parent nucleus. In order to study the neutron deficient isotopes of krypton (A=72,73,74,75) and strontium (A=76,77,78) and to establish the {beta}-strength on the full energy range, a new total absorption spectrometer (TAgS) has been built in the frame of an international collaboration and installed at the (SOLDE/CERN mass separator. For the data analysis, the response function R of the spectrometer has been calculated by means of Monte-Carlo simulations, based on the GEANT4 code, and of a statistical description of the level scheme in the daughter nucleus. The {beta}-feeding distribution has been obtained from experimental spectra through a method based on Bayes theorem and then converted into Gamow-Teller strength. The results coming from the {sup 74}Kr decay analysis allow to describe the ground state of such a nucleus as the coexistence of an oblate shape and of a prolate shape. In the case of {sup 76}Sr, the experimental Gamow-Teller strength distribution strongly indicates a prolate deformation. (author)

  11. Novel concepts and strategies in anticancer metallodrug development : towards oral activity, peptide conjugation and mass spectrometric applications

    Energy Technology Data Exchange (ETDEWEB)

    Meier, S.

    2013-07-01

    Some ruthenium and osmium complexes are promising anticancer drug candidates and the preparation of organometallic RuII and OsII complexes, stabilized by a η6-coordinating arene, represents the latest strategy for obtaining anticancer active metallodrugs with an intriguing activity profile. This PhD thesis reports on the discovery of novel tumour-inhibiting RuII– and OsII–arene metallodrugs and on studies aimed at understanding the molecular interactions of established anticancer agents and drug candidates with biomolecules. Although this field of research is intensely investigated, S,N-bidentate ligand-containing RuII and OsII metallodrugs are reported for the first time. The ligands are based on 2-pyridinecarbothioamides, which show activity as gastric mucosal protectants and are largely non-toxic in vivo (J. Med. Chem., 1990, 33, 327–336). Complexation to the organometallic moiety, however, yields highly cytotoxic metallodrugs in the chemoresistant colon carcinoma and multidrug-resistant non-small lung cancer cell lines. Their aqueous behaviour and drug-likeness properties suggest that this novel family of organometallic anticancer agents may be suitable for oral administration. Additionally, studies with the nucleosome core particle showed that these metallodrugs bind exclusively to the histone proteins at histone dimer–dimer and dimer–tetramer interfaces and therefore, may interfere with chromatin dynamics as a possible mode of action. Organometallic RuII–arene metallodrugs based on O,O-bidentate pyronato ligands typically show low antiproliferative activity. Intriguingly, triazolyl-modified pyrones coordinated to RuII–p-cymene yield highly cytotoxic agents in vitro. The strategy of triazolyl modification was followed to prepare the first organometallic Ru–peptide bioconjugate with cytotoxic activity in the low micromolar range in an ovarian cancer cell line. The metal–peptide bioconjugate was thoroughly characterized by different methods

  12. Photoionization mass spectrometric studies of selected compounds in a molecular beam

    Energy Technology Data Exchange (ETDEWEB)

    Trott, W.M.

    1979-03-01

    Photoionization efficiency curves have been measured at moderate to high resolution for several species produced in supersonic molecular beams of acetone, acetone-d/sub 6/ and CS/sub 2/. The molecular beam photoionization mass spectrometer which has been assembled for this work is described. The performance of this instrument has been characterized by a number of experiments and calculations.

  13. Mass spectrometric study of selected precursors and degradation products of chemical warfare agents

    Czech Academy of Sciences Publication Activity Database

    Papoušková, B.; Bednář, P.; Fryšová, I.; Stýskala, J.; Hlaváč, J.; Barták, P.; Ulrichová, J.; Jirkovský, Jaromír; Lemr, K.

    2007-01-01

    Roč. 42, č. 12 (2007), s. 1550-1561 ISSN 1076-5174 Grant - others:The Organization for the Prohibition of Chemical Weapons (NL) L/ICA/ICB/84322/04 Institutional research plan: CEZ:AV0Z40400503 Source of funding: V - iné verejné zdroje Keywords : mass spectrometry * chemical warfare agent * high performance liquid chromatography * LC/MS Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.062, year: 2007

  14. Threshold photoelectron--photonion coincidence mass spectrometric study of ethylene and ethylene-d4

    International Nuclear Information System (INIS)

    Stockbauer, R.; Inghram, M.G.

    1975-01-01

    Experimental curves have been obtained for the fragmentation of ethylene and ethylene-d 4 ions as a function of the internal energy of those ions using threshold photoelectron--photoion coincidence mass spectrometry. The results are compared with the previous results of photoionization mass spectrometry, He I photoelectron--photoion coicidence, charge exchange experiments, and with quasiequilibrium theory (QET) calculations. The discrepancies between results of these previous experiments and QET calculations do not appear in the present data. It is suggested that ion--molecule reactions competing with charge exchange has led to erroneous conclusions in the interpretation of the charge exchange data. It is concluded that QET does describe the fragmentation of ethylene and ethylene-d 4 within the limits of the data and calculations available. The secondary ion fragmentation C 2 H 4 + → C 2 H 3 + +H → C 2 H 2 + +2H is discussed in detail with regard to the C 2 H 3 + fragment ion internal energy distribution

  15. X-ray spectrometric determination of glass content of melts incorporating radioactive waste: a feasibility study

    International Nuclear Information System (INIS)

    Slates, R.V.

    1978-09-01

    X-ray fluorescence spectrometry was evaluated for the determination of glass content and homogeneity of glass incorporating high-level radioactive waste. Accuracy and precision were determined for analyses of Al 2 O 3 , SiO 2 , CaO, TiO 2 , MnO, Fe 2 O 3 , and NiO in specimens of known composition. These specimens were prepared by fusing powdered glass with nonradioactive synthetic waste. Matrix effects of sodium on these analyses were specifically evaluated. X-ray fluorescence spectrometry was shown to be applicable to the proposed determinations by comparing the known glass contents of 14 glass waste compositions with those calculated from experimentally determined concentrations of SiO or TiO 2

  16. High-precision mass spectrometric analysis using stable isotopes in studies of children

    NARCIS (Netherlands)

    Schierbeek, Henk; van den Akker, Chris H. P.; Fay, Laurent B.; van Goudoever, Johannes B.

    2012-01-01

    The use of stable isotopes combined with mass spectrometry (MS) provides insight into metabolic processes within the body. Herein, an overview on the relevance of stable isotope methodology in pediatric research is presented. Applications for the use of stable isotopes with MS cover carbohydrate,

  17. Mass spectrometric studies of stable isotope-labelled carboxylic acid derivatives

    International Nuclear Information System (INIS)

    Andersson, B.Aa.; Dinger, F.; Dinh-Nguyen, N.

    1975-01-01

    Low resolution mass spectra of deuterium and carbon-13 labelled fatty acid pyrrolidides are discussed. The simple fragmentation pattern of pyrrolidides makes them superior to other derivatives, regarding location of isotopes. Deuteriation of ethylenic fatty acid pyrrolidides therefore seems to be an improved method to locate carbon-carbon double bonds by mass spectrometry. (author)

  18. [Mass spectrometric and quantum chemical study of dimeric associates of nucleosides].

    Science.gov (United States)

    Sukhodub, L F; Aksenov, S A; Boldeskul, A I

    1995-01-01

    Deoxyribonucleosides H-bonded pairs were investigated using fast atom bombardment mass spectrometry and MNDO/H quantum chemistry method. It was shown that "rare" (enol or imin) forms of the nitrogen bases could form pairs with energy comparable with "canonical" base pair energy. It was shown that pair stability rows, which are measured using different experimental techniques, were in conformity each with other.

  19. A VUV photoionization organic aerosol mass spectrometric study with synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Fang Wenzheng; Lei Gong; Shan Xiaobin; Liu Fuyi [School of Nuclear Science and Technology, National Synchrotron Radiation Laboratory, University of Science and Technology of China, Anhui, Hefei 230029 (China); Wang Zhenya [Laboratory of Environmental Spectroscopy, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031 (China); Sheng Liusi, E-mail: lssheng@ustc.edu.cn [School of Nuclear Science and Technology, National Synchrotron Radiation Laboratory, University of Science and Technology of China, Anhui, Hefei 230029 (China)

    2011-04-15

    Research highlights: {yields} A photoionization aerosol time-of-flight mass spectrometer (ATOFMS) has been developed for on-line analysis of organic compounds in aerosol particles using tunable vacuum ultraviolet (VUV) synchrotron radiation. {yields} The degree of fragmentation of molecule can be controlled either by the heater temperature or by the photon energy. {yields} The direct determination of the IEs of benzopheneone (9.07 eV), salicylic acid (8.72 eV), and urea (9.85 eV) are measured from the photoionization efficiency spectra. {yields} The species can be identified by their molecular and fragment ions weights as well as by the comparisions between their theoretical and experimental ionization energies. - Abstract: A photoionization aerosol time-of-flight mass spectrometer (ATOFMS) has been developed for on-line analysis of organic compounds in aerosol particles using tunable vacuum ultraviolet (VUV) synchrotron radiation. Aerosol particles can be sampled directly from atmospheric pressure and are focused through an aerodynamic lens assembly into the mass spectrometer. The particles are vaporized when they impact on a heater, and then the nascent vapor is softly photoionized by synchrotron radiation. The degree of fragmentation of molecule can be controlled either by the heater temperature or by the photon energy. Thus, fragment-free tunable VUV mass spectra are obtained by tuning the photon energy close to the ionization energies (IEs) of the sample molecules. The direct determination of the IEs of benzophenone (9.07 eV), salicylic acid (8.72 eV), and urea (9.85 eV) are measured from the photoionization efficiency spectra with uncertainties of {+-}50 meV. Ab initio calculations have been employed to predict the theoretical ionization energy.

  20. Mass-spectrometric study of boron derivatives of fluorinated β-diketones

    International Nuclear Information System (INIS)

    Lozinskij, M.O.; Fialkov, Yu.A.; Khomenko, V.S.; Rasshinina, T.A.

    1986-01-01

    A series of complexes of fluorinated β-diketones with boron difluoride is synthesized. Ways of their fragmentation and stability at electron collision are determined. Specific decay of perfluorinated and adamantane groups followed by formation of new β-diketonate ions of linear or cyclic structure is characteristic of the investigated complexes in a gas phase. Possibility of trapping of hydrogen atoms by β-diketonate ions in a gaseous phase is detected

  1. The Mass Spectrometric Ortho Effect Studied for All 209 PCB Congeners

    Science.gov (United States)

    A method for the determination of polychlorinated biphenyls (PCBs) in caulk was developed; with application to a set of caulk and window glazing material samples. This method was evaluated by analyzing a combination of 47 samples of caulk, glazing materials, and including quality...

  2. Photoionization mass spectrometric studies of selected compounds in a molecular beam

    International Nuclear Information System (INIS)

    Trott, W.M.

    1979-03-01

    Photoionization efficiency curves have been measured at moderate to high resolution for several species produced in supersonic molecular beams of acetone, acetone-d 6 and CS 2 . The molecular beam photoionization mass spectrometer which has been assembled for this work is described. The performance of this instrument has been characterized by a number of experiments and calculations

  3. Mass Spectrometric Studies of Reductive Elimination from Pd(IV) Complexes

    Czech Academy of Sciences Publication Activity Database

    Hývl, Jakub; Roithová, J.

    2014-01-01

    Roč. 16, č. 1 (2014), s. 200-203 ISSN 1523-7060 Grant - others:GA ČR(CZ) GAP207/11/0338 Institutional support: RVO:61388963 Keywords : cross - coupling reactions * oxidative addition * palladium(IV) Subject RIV: CC - Organic Chemistry Impact factor: 6.364, year: 2014

  4. Ion chemistry in germane/fluorocompounds gaseous mixtures: a mass spectrometric and theoretical study.

    Science.gov (United States)

    Antoniotti, Paola; Rabezzana, Roberto; Turco, Francesca; Borocci, Stefano; Giordani, Maria; Grandinetti, Felice

    2008-10-01

    The ion-molecule reactions occurring in GeH(4)/NF(3), GeH(4)/SF(6), and GeH(4)/SiF(4) gaseous mixtures have been investigated by ion trap mass spectrometry and ab initio calculations. While the NF(x)(+) (x=1-3) react with GeH(4) mainly by the exothermic charge transfer, the open-shell Ge(+) and GeH(2)(+) undergo the efficient F-atom abstraction from NF(3) and form GeF(+) and F-GeH(2)(+) as the only ionic products. The mechanisms of these two processes are quite similar and involve the formation of the fluorine-coordinated complexes Ge-F-NF(2)(+) and H(2)Ge-F-NF(2)(+), their subsequent crossing to the significantly more stable isomers FGe-NF(2)(+) and F-GeH(2)-NF(2)(+), and the eventual dissociation of these ions into GeF(+) (or F-GeH(2)(+)) and NF(2). The closed-shell GeH(+) and GeH(3)(+) are instead much less reactive towards NF(3), and the only observed process is the less efficient formation of GeF(+) from GeH(+). The theoretical investigation of this unusual H/F exchange reaction suggests the involvement of vibrationally-hot GeH(+). Passing from NF(3) to SF(6) and SiF(4), the average strength of the M-F bond increases from 70 to 79 and 142 kcal mol(-1), and in fact the only process observed by reacting GeH(n)(+) (n=0-3) with SF(6) and SiF(4) is the little efficient F-atom abstraction from SF(6) by Ge(+). Irrespective of the experimental conditions, we did not observe any ionic product of Ge-N, Ge-S, or Ge-Si connectivity. This is in line with the previously observed exclusive formation of GeF(+) from the reaction between Ge(+) and C-F compounds such as CH(3)F. Additionally observed processes include in particular the conceivable formation of the elusive thiohypofluorous acid FSH from the reaction between SF(+) and GeH(4).

  5. Mass spectrometric studies of the complexing behaviour of actinide ions in solution

    International Nuclear Information System (INIS)

    Steppert, Michael

    2012-01-01

    As the long-term radiotoxicity of spent nuclear fuel is governed by Plutonium and the Minor Actinides, these elements are focussed on for investigations in the framework of safety assessment for nuclear waste repositories. To shed more light on the selectivity of the partitioning ligands BTP and BTBP towards the extraction of trivalent actinides, the complexes these ligands form with lanthanides in octanolic solution were characterized. The differences in the extraction efficiencies among the different lanthanides were traced back to the varying preferential formation of Ln(BTP)3 complexes, depending on the ionic radius of the lanthanides. Additionally it was shown that depending on the sterical demand of BTBP ligands nitrate anions coordinate in the first coordination shell of Eu(BTBP)2-complexes. As the behavior of Plutonium under geochemical conditions is of particular interest for the safety assessment of potential nuclear waste repositories, the second part of the thesis focuses on the hydrolysis and colloid formation behavior of aqueous Plutonium solutions. The solution species of Zirconium(IV) as analogue for Plutonium(IV) as well as of Uranium(VI) and Plutonium(VI) were characterized and quantified by means of electrospray ionization mass spectrometry. Moreover the colloid-induced reduction of Pu(V) to Pu(IV) and the subsequent formation of colloidal species was investigated. [de

  6. Terverticillate penicillia studied by direct electrospray mass spectrometric profiling of crude extracts II. Database and identification

    DEFF Research Database (Denmark)

    Smedsgaard, Jørn

    1997-01-01

    A mass spectral database was built using standard instrument software from 678 electrospray mass spectra (mass profiles) from crude fungal extracts of terverticillate taxa within the genus Penicillium. The match factors calculated from searching all the mass profiles stored in the database were...

  7. Rapid Mass Spectrometric Analysis of a Novel Fucoidan, Extracted from the Brown Alga Coccophora langsdorfii

    Directory of Open Access Journals (Sweden)

    Stanislav D. Anastyuk

    2014-01-01

    Full Text Available The novel highly sulfated (35% fucoidan fraction Cf2 , which contained, along with fucose, galactose and traces of xylose and uronic acids was purified from the brown alga Coccophora langsdorfii. Its structural features were predominantly determined (in comparison with fragments of known structure by a rapid mass spectrometric investigation of the low-molecular-weight fragments, obtained by “mild” (5 mg/mL and “exhaustive” (maximal concentration autohydrolysis. Tandem matrix-assisted laser desorption/ionization mass spectra (MALDI-TOF/TOFMS of fucooligosaccharides with even degree of polymerization (DP, obtained by “mild” autohydrolysis, were the same as that observed for fucoidan from Fucus evanescens, which have a backbone of alternating (1 → 3- and (1 → 4 linked sulfated at C-2 and sometimes at C-4 of 3-linked α-L-Fucp residues. Fragmentation patterns of oligosaccharides with odd DP indicated sulfation at C-2 and at C-4 of (1 → 3 linked α-L-Fucp residues on the reducing terminus. Minor sulfation at C-3 was also suggested. The “exhaustive” autohydrolysis allowed us to observe the “mixed” oligosaccharides, built up of fucose/xylose and fucose/galactose. Xylose residues were found to occupy both the reducing and nonreducing termini of FucXyl disaccharides. Nonreducing galactose residues as part of GalFuc disaccharides were found to be linked, possibly, by 2-type of linkage to fucose residues and were found to be sulfated, most likely, at position C-2.

  8. Mass spectrometric identification of phospholipids in human tears and tear lipocalin.

    Science.gov (United States)

    Dean, Austin W; Glasgow, Ben J

    2012-04-02

    The purpose of this article was to identify by mass spectrometry phosphocholine lipids in stimulated human tears and determine the molecules bound to tear lipocalin or other proteins. Tear proteins were separated isocratically from pooled stimulated human tears by gel filtration fast performance liquid chromatography. Separation of tear lipocalin was confirmed by SDS tricine gradient PAGE. Protein fractions were extracted with chloroform/methanol and analyzed with electrospray ionization MS/MS triple quadrupole mass spectrometry in precursor ion scan mode for select leaving groups. For quantification, integrated ion counts were derived from standard curves of authentic compounds of phosphatidylcholine (PC) and phosphatidylserine. Linear approximation was possible from integration of the mass spectrometrically obtained ion peaks at 760 Da for the PC standard. Tears contained 194 ng/mL of the major intact PC (34:2), m/z 758.6. Ten other monoisotopic phosphocholines were found in tears. A peak at 703.3 Da was assigned as a sphingomyelin. Four lysophosphatidylcholines (m/z 490-540) accounted for about 80% of the total integrated ion count. The [M+H](+) compound, m/z 496.3, accounted for 60% of the signal intensity. Only the tear lipocalin-bearing fractions showed phosphocholines (104 ng/mL). Although the intact phospholipids bound to tear lipocalin corresponded precisely in mass and relative signal intensity to that found in tears, we did not identify phosphocholines between m/z 490 and 540 in any of the gel-filtration fractions. Phospholipids, predominantly lysophospholipids, are present in tears. The higher mass intact PCs in tears are native ligands of tear lipocalin.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-10-24

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

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

    International Nuclear Information System (INIS)

    Herrero Latorre, C.; Álvarez Méndez, J.; Barciela García, J.; García Martín, S.; Peña Crecente, R.M.

    2012-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Jian [State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University, Xiamen 361102 (China); Department of Chemistry and Biochemistry, University of Texas, 700 Planetarium Place, Arlington, TX 76019 (United States); Sengupta, Mrinal K. [Department of Chemistry and Biochemistry, University of Texas, 700 Planetarium Place, Arlington, TX 76019 (United States); Thermo Fisher Scientific, Dionex Products, 445 Lakeside Drive, Sunnyvale, CA, 94085 (United States); Yuan, Dongxing [State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University, Xiamen 361102 (China); Dasgupta, Purnendu K., E-mail: Dasgupta@uta.edu [Department of Chemistry and Biochemistry, University of Texas, 700 Planetarium Place, Arlington, TX 76019 (United States)

    2014-06-01

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

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

    International Nuclear Information System (INIS)

    Ma, Jian; Sengupta, Mrinal K.; Yuan, Dongxing; Dasgupta, Purnendu K.

    2014-01-01

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

  13. Evaluation of mass spectrometric data using principal component analysis for determination of the effects of organic lakes on protein binder identification.

    Science.gov (United States)

    Hrdlickova Kuckova, Stepanka; Rambouskova, Gabriela; Hynek, Radovan; Cejnar, Pavel; Oltrogge, Doris; Fuchs, Robert

    2015-11-01

    Matrix-assisted laser desorption/ionisation-time of flight (MALDI-TOF) mass spectrometry is commonly used for the identification of proteinaceous binders and their mixtures in artworks. The determination of protein binders is based on a comparison between the m/z values of tryptic peptides in the unknown sample and a reference one (egg, casein, animal glues etc.), but this method has greater potential to study changes due to ageing and the influence of organic/inorganic components on protein identification. However, it is necessary to then carry out statistical evaluation on the obtained data. Before now, it has been complicated to routinely convert the mass spectrometric data into a statistical programme, to extract and match the appropriate peaks. Only several 'homemade' computer programmes without user-friendly interfaces are available for these purposes. In this paper, we would like to present our completely new, publically available, non-commercial software, ms-alone and multiMS-toolbox, for principal component analyses of MALDI-TOF MS data for R software, and their application to the study of the influence of heterogeneous matrices (organic lakes) for protein identification. Using this new software, we determined the main factors that influence the protein analyses of artificially aged model mixtures of organic lakes and fish glue, prepared according to historical recipes that were used for book illumination, using MALDI-TOF peptide mass mapping. Copyright © 2015 John Wiley & Sons, Ltd.

  14. Concurrent Label-Free Mass Spectrometric Analysis of Dystrophin Isoform Dp427 and the Myofibrosis Marker Collagen in Crude Extracts from mdx-4cv Skeletal Muscles

    Science.gov (United States)

    Murphy, Sandra; Zweyer, Margit; Mundegar, Rustam R.; Henry, Michael; Meleady, Paula; Swandulla, Dieter; Ohlendieck, Kay

    2015-01-01

    The full-length dystrophin protein isoform of 427 kDa (Dp427), the absence of which represents the principal abnormality in X-linked muscular dystrophy, is difficult to identify and characterize by routine proteomic screening approaches of crude tissue extracts. This is probably related to its large molecular size, its close association with the sarcolemmal membrane, and its existence within a heterogeneous glycoprotein complex. Here, we used a careful extraction procedure to isolate the total protein repertoire from normal versus dystrophic mdx-4cv skeletal muscles, in conjunction with label-free mass spectrometry, and successfully identified Dp427 by proteomic means. In contrast to a considerable number of previous comparative studies of the total skeletal muscle proteome, using whole tissue proteomics we show here for the first time that the reduced expression of this membrane cytoskeletal protein is the most significant alteration in dystrophinopathy. This agrees with the pathobiochemical concept that the almost complete absence of dystrophin is the main defect in Duchenne muscular dystrophy and that the mdx-4cv mouse model of dystrophinopathy exhibits only very few revertant fibers. Significant increases in collagens and associated fibrotic marker proteins, such as fibronectin, biglycan, asporin, decorin, prolargin, mimecan, and lumican were identified in dystrophin-deficient muscles. The up-regulation of collagen in mdx-4cv muscles was confirmed by immunofluorescence microscopy and immunoblotting. Thus, this is the first mass spectrometric study of crude tissue extracts that puts the proteomic identification of dystrophin in its proper pathophysiological context. PMID:28248273

  15. A rapid method for α-spectrometric analysis of radium isotopes in natural waters using ion-selective membrane technology

    International Nuclear Information System (INIS)

    Purkl, Stefan; Eisenhauer, Anton

    2003-01-01

    An α-spectrometric method for the rapid determination of radium isotopes ( 223 Ra, 224 Ra and 226 Ra) in environmental samples is presented. Using Empore TM Radium Rad Disks complete separation of the target radionuclides is achieved. The high selectivity of these Rad Disks allows the straightforward use of 225 Ra as yield tracer. Chemical yield is up to 92±9%. The chemical procedure can be accomplished within 5 h. α-Sources show energy resolution in the range of typically 26-40 keV (FWHM). Despite minimal thickness of the sources no significant radon (Rn) losses can be observed

  16. Characterization of HPGe gamma spectrometric detectors systems for Instrumental Neutron Activation Analysis (INAA) at the Colombian Geological Survey

    Energy Technology Data Exchange (ETDEWEB)

    Sierra, O., E-mail: osierra@sgc.gov.co; Parrado, G., E-mail: gparrado@sgc.gov.co; Cañón, Y.; Porras, A.; Alonso, D.; Herrera, D. C.; Peña, M., E-mail: mlpena@sgc.gov.co; Orozco, J. [Colombian Geological Survey, Nuclear Affairs Technical Division, Neutron Activation Analysis Laboratory, Bogota D. C. (Colombia)

    2016-07-07

    This paper presents the progress made by the Neutron Activation Analysis (NAA) laboratory at the Colombian Geological Survey (SGC in its Spanish acronym), towards the characterization of its gamma spectrometric systems for Instrumental Neutron Activation Analysis (INAA), with the aim of introducing corrections to the measurements by variations in sample geometry. Characterization includes the empirical determination of the interaction point of gamma radiation inside the Germanium crystal, through the application of a linear model and the use of a fast Monte Carlo N-Particle (MCNP) software to estimate correction factors for differences in counting efficiency that arise from variations in sample density between samples and standards.

  17. A Chemical Eight Group Separation Method for Routine Use in Gamma Spectrometric Analysis. II. Detailed analytical schema

    Energy Technology Data Exchange (ETDEWEB)

    Samsahl, K

    1961-06-15

    A detailed ion-exchange procedure for the separation of chemical elements in eight groups suitable for subsequent gamma spectrometric analysis is described. The method has been in use for gamma spectrometry of some inorganic - but mostly organic - samples for one year. The separation time for inorganic samples, is usually about 1.5 hours and for organic samples as least 2 hours. One man can separate and count three samples per day. In comparative measurements of short-lived isotopes in biological material 10-12 elements can be analysed thus making possible 30 - 35 determinations per day for one man.

  18. Units for designing multidetector system for spectrometric data storage on the base of the 16Kx24 bit memory device

    International Nuclear Information System (INIS)

    Vagov, V.A.; Korobchenko, M.L.; Sirotin, A.P.

    1985-01-01

    Main units of the system for spectrometric data accumulation on the base of the 16Kx24 bit memory device are considered. Input units: counter unit and unit for organization of analysis are described. The applied method for multiplexing data removed into the counter unit permits to essentially reduce hardware loading. Application of some special functions in the unit for analysis organization simplifies data accumulation control to a large extent. The unit for analysis organization allows application of the memory with an address field up to 64K

  19. Recent progress in the development of CsI(Tl) crystal-Si-photodiode spectrometric detection assemblies

    International Nuclear Information System (INIS)

    Semynozhenko, V.P.; Grinyov, B.V.; Nekrasov, V.V.; Borodenko, Yu.A.

    2005-01-01

    Highly sensitive spectrometric γ-detection assemblies are developed using a comprehensive approach (optimization of crystal growth conditions as well as of treatment and packing of scintillators, creation of low-noise charge-sensitive preamplifiers and shapers). The detection assemblies with CsI(Tl)≤100 cm 3 have a sensitivity of about 20 pulse/s(mcR/h), their energy resolution with respect to 137 Cs γ-line being ≤8.5%. The assemblies with lesser scintillator volumes (1-5 cm 3 ) provide a resolution lower than 6% with respect to 137 Cs and ≤40% with respect to 241 Am

  20. Radioactive and geological analysis of airborne gamma spectrometric data for locating favorable traps for uranium prospecting in the Syrian desert (Area-1), Syria

    International Nuclear Information System (INIS)

    Asfahani, J.; Al-Hent, R.; Aissa, M.

    2012-01-01

    Statistical analysis has been applied to the airborne spectrometric data for the Syrian desert (Area-1), Syria in order to characterize and isolate the anomalous uranium radioactive zones. Equivalent uranium eU values vary between a minimum of 0.01 and a maximum of 32.74 ppm. Uranium prospecting methodology recently proposed is successfully applied in order to explain the origin of the radioactive anomalies related to Area-1. The dominant geological conditions effectively contributing to the uranium radioactive anomalies in the study area have been determined through the analysis of five radioactive-geological profiles. Different favorable traps have been identified and localized for uranium prospecting. Those uranium traps merit further detailed exploration for determining their uranium potential with depth. - Highlights: ► Determine the radioactive characteristics of Area-1. ► Apply a uranium prospecting methodology for guiding uranium exploration activities in Area-1. ► Explain the origin of the radioactive anomalies in Area-1. ► Relate the structural and geological conditions with the anomalous radioactive occurrences.

  1. Identification of Polish cochineal (Porphyrophora polonica L.) in historical textiles by high-performance liquid chromatography coupled with spectrophotometric and tandem mass spectrometric detection.

    Science.gov (United States)

    Lech, Katarzyna; Jarosz, Maciej

    2016-05-01

    The present work reports a method for identification of Polish cochineal (Porphyrophora polonica L.) in historical fabrics by the use of high-performance liquid chromatography coupled with diode array and tandem mass spectrometric detection with electrospray ionization (HPLC-DAD-ESI MS/MS). This hyphened technique allows detection and identification of 16 new minor colorants present in the discussed scale insect (including two previously observed by Wouters and Verhecken (Ann Soc Entomol Fr. 1989;25:393-410), but specified only as compounds of unknown structures) that do not occur (e.g., in American cochineal). The MS/MS experiments, complemented with UV-VIS data, enable identification of mono- and di-, C- and O-hexosides of kermesic and flavokermesic acids or their derivatives. The present paper introduces a fingerprint of color compounds present in Polish cochineal and defines them, particularly pp6 (ppI, O-hexoside of flavokermesic acid), as its markers allow distinguishing of Polish-cochineal reds from the American ones. Usefulness of the selected set of markers for identification of Polish cochineal has been demonstrated in the examination of textiles from the collection of the National Museum in Warsaw using the multiple reaction monitoring (MRM) method, originally elaborated on the basis of this study.

  2. Basis material decomposition method for material discrimination with a new spectrometric X-ray imaging detector

    Science.gov (United States)

    Brambilla, A.; Gorecki, A.; Potop, A.; Paulus, C.; Verger, L.

    2017-08-01

    Energy sensitive photon counting X-ray detectors provide energy dependent information which can be exploited for material identification. The attenuation of an X-ray beam as a function of energy depends on the effective atomic number Zeff and the density. However, the measured attenuation is degraded by the imperfections of the detector response such as charge sharing or pile-up. These imperfections lead to non-linearities that limit the benefits of energy resolved imaging. This work aims to implement a basis material decomposition method which overcomes these problems. Basis material decomposition is based on the fact that the attenuation of any material or complex object can be accurately reproduced by a combination of equivalent thicknesses of basis materials. Our method is based on a calibration phase to learn the response of the detector for different combinations of thicknesses of the basis materials. The decomposition algorithm finds the thicknesses of basis material whose spectrum is closest to the measurement, using a maximum likelihood criterion assuming a Poisson law distribution of photon counts for each energy bin. The method was used with a ME100 linear array spectrometric X-ray imager to decompose different plastic materials on a Polyethylene and Polyvinyl Chloride base. The resulting equivalent thicknesses were used to estimate the effective atomic number Zeff. The results are in good agreement with the theoretical Zeff, regardless of the plastic sample thickness. The linear behaviour of the equivalent lengths makes it possible to process overlapped materials. Moreover, the method was tested with a 3 materials base by adding gadolinium, whose K-edge is not taken into account by the other two materials. The proposed method has the advantage that it can be used with any number of energy channels, taking full advantage of the high energy resolution of the ME100 detector. Although in principle two channels are sufficient, experimental measurements show

  3. In situ monitoring of molecular changes during cell differentiation processes in marine macroalgae through mass spectrometric imaging.

    Science.gov (United States)

    Kessler, Ralf W; Crecelius, Anna C; Schubert, Ulrich S; Wichard, Thomas

    2017-08-01

    Matrix-assisted laser desorption/ionization mass spectrometric imaging (MALDI-MSI) was employed to discriminate between cell differentiation processes in macroalgae. One of the key developmental processes in the algal life cycle is the production of germ cells (gametes and zoids). The gametogenesis of the marine green macroalga Ulva mutabilis (Chlorophyta) was monitored by metabolomic snapshots of the surface, when blade cells differentiate synchronously into gametangia and giving rise to gametes. To establish MSI for macroalgae, dimethylsulfoniopropionate (DMSP), a known algal osmolyte, was determined. MSI of the surface of U. mutabilis followed by chemometric data analysis revealed dynamic metabolomic changes during cell differentiation. DMSP and a total of 55 specific molecular biomarkers, which could be assigned to important stages of the gametogenesis, were detected. Our research contributes to the understanding of molecular mechanisms underlying macroalgal cell differentiation. Graphical abstract Molecular changes during cell differentiation of the marine macroalga Ulva were visualized by matrix assisted laser desorption/ionization mass spectrometric imaging (MALDI-MSI).

  4. Method Validation for the Gamma-ray Spectrometric Determination of Natural Radioactive Nuclides in NORM Samples - Method Validation for the Gamma-ray Spectrometric Determination of Natural Radionuclides in raw materials and by-products

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Young-Yong; Lim, Jong-Myoung; Jang, Mee; Kim, Chang-Jong; Chung, Kun Ho; Kang, Mun Ja; Choi, Geun-Sik [Environmental Radioactivity Assessment Team, Korea Atomic Energy Research Institute, 111, Daedeok-daero 989, Yuseong, Daejeon, 305-353 (Korea, Republic of)

    2014-07-01

    It has established the 'Act on safety control of radioactive rays around living environment' in Korea, since 2011, to protect the public from natural occurring radioactive materials (NORM) and their by-products. The increasing concerns regarding the radioactivity of those materials therefore dictate many demands for the radioactive analysis for them. There are several methods to determine the concentration of natural radionuclides, such as {sup 235}U, {sup 238}U, {sup 226}Ra, {sup 232}Th, and so on, through a radiochemical analysis using an alpha spectrometer, mass spectrometer and liquid scintillation counter. However, gamma-ray spectroscopy still has an effect on the assessment of radioactive concentration for these nuclides and their progenies. To adapt a gamma spectrometer to the determination of natural radionuclides, the feasibility of their analysis methods should be first verified and validated with respect to accuracy and time and cost constraints. In general, one of the well-known processes in analyzing uranium with a gamma spectrometer is an indirect measurement using the secular equilibrium state with their progenies in a sample. This method, however, demands the time elapsed about 3 weeks to reach the equilibrium state between {sup 226}Ra and {sup 222}Rn and the sufficient integrity of a sample bottle to prevent the leakage of radon isotopes which is a form of noble gas. The simple and quick method is to directly measure a full energy absorption peak of 186.2 keV from {sup 226}Ra without the secular equilibrium state between {sup 226}Ra and {sup 222}Rn in the common sample bottle. However, this direct measurement also has difficulties about the interference with a full energy absorption peak of 185.7 keV from {sup 235}U. In this study, direct measurement with the interference correction technique, which uses several reference peaks for gamma-rays from {sup 235}U and {sup 234}Th, and indirect measurement, which means the identification of {sup

  5. Stabilization of spectra provided by a gamma-ray spectrometer. Application to the construction of a stabilizer; Stabilisation des spectres fournis par un spectrometre a rayons gamma. Application a la realisation d'un stabilisateur

    Energy Technology Data Exchange (ETDEWEB)

    Detourne, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-06-15

    This research is concerned with the stabilization of spectra provided by a gamma-ray spectrometer. It is required to hold the calibration straight line of the spectrometer in a position which is fixed initially to better than 5x10{sup -5} channel. A prototype numerical stabilizer has been constructed : the SPECTROSTAB; it is made up of two independent control loops; one of these makes the spectrometer gain depend on the derivatives of a reference peak at high energies; the other makes the origin of the energy scale depend on the derivatives of a second reference peak at low energies A theoretical study of the behaviour of a control loop shows that a direct action stabilizer gives the most accurate stabilization; the loss in resolving power on the theoretical peaks of the spectra attains about 1 % with a scintillation detector, and 10 % with a semi-conductor detector. Various tests show that the expected results are obtained and that the displacement of the spectral peaks produced by the derivatives are hidden by errors in the calculation of the peak abscissae. (author) [French] Cette etude a pour objet la stabilisation des spectres fournis par un spectrometre a rayons gamma. On veut maintenir la droite d'etalonnage du spectrometre dans une position fixee initialement a mieux de 6.10{sup -5} canal pres. On realise un prototype de stabilisateur numerique, le SPECTROSTAB; il comprend deux boucles d'asservissement independantes; l'une d'elles asservit le gain du spectrometre aux derives d'un pic de reference aux hautes energies; l'autre asservit l'origine de l'echelle des energies aux derives d'un second pic de reference aux basses energies. Une etude theorique du comportement d'une boucle d'asservissement montre qu'un stabilisateur a action directe permet la stabilisation la plus precise; la perte en resolution sur les pics theoriques des spectres atteint environ 1 % avec un detecteur a scintillateur et 10 % avec un detecteur a semi-conducteur. Divers essais montrent

  6. Alkylation of human serum albumin by sulfur mustard in vitro and in vivo : Mass spectrometric analysis of a cysteine adduct as a sensitive biomarker of exposure

    NARCIS (Netherlands)

    Noort, D.; Hulst, A.G.; Jong, L.P.A. de; Benschop, H.P.

    1999-01-01

    To develop a mass spectrometric assay for the detection of sulfur mustard adducts with human serum albumin, the following steps were performed: quantitation of the binding of the agent to the protein by using [14C] sulfur mustard and analysis of acidic and tryptic digests of albumin from blood after

  7. Liquid chromatography-tandem mass spectrometric assay for the tyrosine kinase inhibitor afatinib in mouse plasma using salting-out liquid-liquid extraction

    NARCIS (Netherlands)

    Sparidans, Rolf W; van Hoppe, Stephanie; Rood, Johannes J M; Schinkel, Alfred H; Schellens, Jan H M; Beijnen, Jos H

    2016-01-01

    A quantitative bioanalytical liquid chromatography-tandem mass spectrometric (LC-MS/MS) assay for afatinib, an irreversible inhibitor of the ErbB (erythroblastic leukemia viral oncogene homolog) tyrosine kinase family, was developed and validated. Plasma samples were pre-treated using salting-out

  8. Electronic states and nature of bonding in the molecule YC by all electron ab initio multiconfiguration self-consistent-field calculations and mass spectrometric equilibrium experiments

    DEFF Research Database (Denmark)

    Shim, Irene; Pelino, Mario; Gingerich, Karl A.

    1992-01-01

    , and they hardly contribute to the bonding. The chemical bond in the YC molecule is polar with charge transfer from Y to C giving rise to a dipole moment of 3.90 D at 3.9 a.u. in the 4PI ground state. Mass spectrometric equilibrium investigations in the temperature range 2365-2792 K have resulted...

  9. Environmental Technology Verification Report. Field Portable Gas Chromatograph/Mass Spectrometer. Viking Instruments Corporation SpectraTrak (Trademark) 672

    National Research Council Canada - National Science Library

    Enfield, Wayne

    1997-01-01

    .... This self-contained, field transportable system, whose design has been adapted from laboratory technology, uses a contained, chromatographic column and accompanying mass spectrometer to provide...

  10. Determination of antimycin-A in water by liquid chromatographic/mass spectrometry: single-laboratory validation.

    Science.gov (United States)

    Bernardy, Jeffry A; Hubert, Terrance D; Ogorek, Jacob M; Schmidt, Larry J

    2013-01-01

    An LC/MS method was developed and validated for the quantitative determination and confirmation of antimycin-A (ANT-A) in water from lakes or streams. Three different water sample volumes (25, 50, and 250 mL) were evaluated. ANT-A was stabilized in the field by immediately extracting it from water into anhydrous acetone using SPE. The stabilized concentrated samples were then transported to a laboratory and analyzed by LC/MS using negative electrospray ionization. The method was determined to have adequate accuracy (78 to 113% recovery), precision (0.77 to 7.5% RSD with samples > or = 500 ng/L and 4.8 to 17% RSD with samples < or = 100 ng/L), linearity, and robustness over an LOQ range from 8 to 51 600 ng/L.

  11. Determination of trihalomethanes in waters by ionic liquid-based single drop microextraction/gas chromatographic/mass spectrometry.

    Science.gov (United States)

    Aguilera-Herrador, Eva; Lucena, Rafael; Cárdenas, Soledad; Valcárcel, Miguel

    2008-10-31

    A simple, rapid, solventless method for the determination of trihalomethanes (THMs) (chloroform, bromodichloromethane, dibromochloromethane and bromoform) in water samples is presented. The analytes are extracted from the headspace of the aqueous matrix into a 2 microL drop of the ionic liquid 1-octyl-3-methyl-imidazolium hexafluorophosphate working at 30 degrees C for 30 min. The separation and detection of the target compounds is accomplished by gas chromatography/mass spectrometry owing to the use of an interface that efficiently transfers the analytes extracted in the ionic liquid drop to the gas chromatograph while preventing the ionic liquid from entering the column. The detection limits obtained are below the values compelled by the legislation, ranging from 0.5 microg L(-1) for chloroform and bromodichloromethane to 0.9 microg L(-1) for dibromochloromethane. The use of ionic liquid in the extraction procedure avoids the use of organic solvents and leads to relative standard deviations that range from 3.1% to 4.8%.

  12. Field-portable Gas Chromatograph Mass Spectrometer (GC-MS) Unit for Semi-volatile Compound Analysis in Groundwater

    Science.gov (United States)

    2011-09-01

    the need for a convective oven, greatly reducing the size and power consumption compared to standard GC systems. These modifications to the...spectrometer. In Harsh Environment Mass Spectrometry (HEMS) Conference; September 2007; Cocoa Beach, FL. Science Applications International Corporation

  13. Characterization of phenolic and other polar compounds in peel and flesh of pink guava (Psidium guajava L. cv. 'Criolla') by ultra-high performance liquid chromatography with diode array and mass spectrometric detection.

    Science.gov (United States)

    Rojas-Garbanzo, Carolina; Zimmermann, Benno F; Schulze-Kaysers, Nadine; Schieber, Andreas

    2017-10-01

    Pink guava (Psidium guajava L.) is a highly consumed fruit in tropical countries. Despite of interesting research on health effects of this fruit, investigations into the profile of secondary plant metabolites are scarce. In this study, the phenolic compounds in the peel and flesh of pink guava were characterized by ultra-high performance liquid chromatography with diode array and mass spectrometric detection. Sixty phenolic compounds were characterized by MS 2 and classified as ellagitannins, flavones, flavonols, flavanols, proanthocyanidins, dihydrochalcones, and anthocyanidins, and non-flavonoids such as phenolic acid derivatives, stilbenes, acetophenones, and benzophenones. Forty-two polyphenols are reported for the first time in both peel and flesh, and twenty-four compounds were detected for the first time in P. guajava, e.g., phlorizin, nothofagin, astringin, chrysin-C-glucoside, valoneic acid bilactone, cinnamoyl-glucoside, and two dimethoxycinnamoyl-hexosides. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. 2DB: a Proteomics database for storage, analysis, presentation, and retrieval of information from mass spectrometric experiments.

    Science.gov (United States)

    Allmer, Jens; Kuhlgert, Sebastian; Hippler, Michael

    2008-07-07

    The amount of information stemming from proteomics experiments involving (multi dimensional) separation techniques, mass spectrometric analysis, and computational analysis is ever-increasing. Data from such an experimental workflow needs to be captured, related and analyzed. Biological experiments within this scope produce heterogenic data ranging from pictures of one or two-dimensional protein maps and spectra recorded by tandem mass spectrometry to text-based identifications made by algorithms which analyze these spectra. Additionally, peptide and corresponding protein information needs to be displayed. In order to handle the large amount of data from computational processing of mass spectrometric experiments, automatic import scripts are available and the necessity for manual input to the database has been minimized. Information is in a generic format which abstracts from specific software tools typically used in such an experimental workflow. The software is therefore capable of storing and cross analysing results from many algorithms. A novel feature and a focus of this database is to facilitate protein identification by using peptides identified from mass spectrometry and link this information directly to respective protein maps. Additionally, our application employs spectral counting for quantitative presentation of the data. All information can be linked to hot spots on images to place the results into an experimental context. A summary of identified proteins, containing all relevant information per hot spot, is automatically generated, usually upon either a change in the underlying protein models or due to newly imported identifications. The supporting information for this report can be accessed in multiple ways using the user interface provided by the application. We present a proteomics database which aims to greatly reduce evaluation time of results from mass spectrometric experiments and enhance result quality by allowing consistent data handling

  15. 2DB: a Proteomics database for storage, analysis, presentation, and retrieval of information from mass spectrometric experiments

    Directory of Open Access Journals (Sweden)

    Hippler Michael

    2008-07-01

    Full Text Available Abstract Background The amount of information stemming from proteomics experiments involving (multi dimensional separation techniques, mass spectrometric analysis, and computational analysis is ever-increasing. Data from such an experimental workflow needs to be captured, related and analyzed. Biological experiments within this scope produce heterogenic data ranging from pictures of one or two-dimensional protein maps and spectra recorded by tandem mass spectrometry to text-based identifications made by algorithms which analyze these spectra. Additionally, peptide and corresponding protein information needs to be displayed. Results In order to handle the large amount of data from computational processing of mass spectrometric experiments, automatic import scripts are available and the necessity for manual input to the database has been minimized. Information is in a generic format which abstracts from specific software tools typically used in such an experimental workflow. The software is therefore capable of storing and cross analysing results from many algorithms. A novel feature and a focus of this database is to facilitate protein identification by using peptides identified from mass spectrometry and link this information directly to respective protein maps. Additionally, our application employs spectral counting for quantitative presentation of the data. All information can be linked to hot spots on images to place the results into an experimental context. A summary of identified proteins, containing all relevant information per hot spot, is automatically generated, usually upon either a change in the underlying protein models or due to newly imported identifications. The supporting information for this report can be accessed in multiple ways using the user interface provided by the application. Conclusion We present a proteomics database which aims to greatly reduce evaluation time of results from mass spectrometric experiments and enhance

  16. A study on chemical composition of spices irradiated by electron beam

    International Nuclear Information System (INIS)

    Ding Lianzhong; Ding Shiyue; Zhu Yan; Li Yixu; Zhu Songmei

    1998-01-01

    Quantitative changes in common organic acids and inorganic acids from spices irradiated by electron beam were studied by Dionex-4000i ion chromatograph. The results showed that the acids content of either chilli or the five-spice powder irradiated with a dose of 9.94 kGy did not undergo significant changes in comparison with the control samples. The flavour composition in the five-spice powder irradiated by electron beam was also determined by Finnigan MAT-8230B gas chromatograph-mass spectrometer, and compared to the results by heating treatment (120 deg. C, 30min). The comparison indicated that the effect of electron beam treatment on flavour composition was less than that of heating

  17. A study on chemical composition of spices irradiated by electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Lianzhong, Ding [Inst. of Applied Technical Physics of Zhejiang Province (China); Shiyue, Ding; Yan, Zhu; Yixu, Li [Testing Technology Inst. of Zhejiang Province (China)

    1992-02-01

    Quantitative changes in common organic acids and inorganic acids from spices irradiated by electron beam were studied by Dionex-4000 ion Chromatograph. The results showed that the acids content of either achilli or the five-spice powder irradiated with a dose of 9.94 kGy did not undergo significant changes in comparison with the control samples. The flavour composition in the five-spice powder irradiated by electron beam was also determined by Finnigan MAT-8230B gas chromatograph-mass spectrometer, and compared to the results by heating treatment (120 C, 30 min). The comparison indicated that the effect of electron beam treatment on flavour composition was less than that of heating.

  18. Nonane as a radiolytic product in irradiated bacon

    International Nuclear Information System (INIS)

    Singh, H.; Guerrero, A.; Kremers, W.

    1993-01-01

    Formation of nonane in irradiated bacon has been confirmed by gas chromatographic/mass spectrometric (GC/MS) analysis of irradiated nitrogen-flushed homogenized bacon in scaled glass vials. Unirradiated bacon did not show the presence of nonane under similar conditions

  19. Simultaneous analysis of plasma free fatty acids and their 3-hydroxy analogs in fatty acid beta-oxidation disorders

    NARCIS (Netherlands)

    Costa, C. G.; Dorland, L.; Holwerda, U.; de Almeida, I. T.; Poll-The, B. T.; Jakobs, C.; Duran, M.

    1998-01-01

    We present a new derivatization procedure for the simultaneous gas chromatographic-mass spectrometric analysis of free fatty acids and 3-hydroxyfatty acids in plasma. Derivatization of target compounds involved trifluoroacetylation of hydroxyl groups and tert-butyldimethylsilylation of the carboxyl

  20. Identification and quantification of flavonoids in human urine samples by column switching liquid chromatography coupled to atmospheric pressure chemical ionization mass spectrometry

    DEFF Research Database (Denmark)

    Nielsen, Salka E.; Freese, R.; Cornett, C.

    2000-01-01

    A rapid and sensitive high-performance liquid chromatographic mass spectrometric (HPLC-MS) method is described for the determination and quantification of 12 dietary flavonoid glycosides and aglycons in human urine samples. Chromatographic separation of the analytes of interest was achieved...

  1. A new, simple assay for long-chain acyl-CoA dehydrogenase in cultured skin fibroblasts using stable isotopes and GC-MS

    NARCIS (Netherlands)

    Niezen-Koning, K. E.; Wanders, R. J.; Nagel, G. T.; IJlst, L.; Heymans, H. S.

    1992-01-01

    In this paper, we present a new method for measurement of long-chain acyl-CoA dehydrogenase (LCAD) activities in cultured skin fibroblasts. The method is based upon gas chromatographic/mass spectrometric determination of 3-OH-hexadecanoic acid formed during incubation of fibroblasts in a medium

  2. Multi-element determination in environmental samples by mass spectrometric isotope dilution analysis using thermal ionization. Pt. 2

    International Nuclear Information System (INIS)

    Hilpert, K.; Waidmann, E.

    1988-01-01

    An analytical procedure for the multi-element analysis of the elements Fe, Ni, Cu, Zn, Ga, Rb, Sr, Cd, Ba, Tl, and Pb in pine needles by mass spectrometric isotope dilution analysis using thermal ionization has been reported in Part I of this paper. This procedure is now transferred to the non-vegetable material 'Oyster Tissue' (Standard Reference Material 1566, National Bureau of Standards, USA). By a modification of the analytical procedure, it was possible to determine Cr in this material in addition to the aforementioned elements. No concentrations are certified for the elements Ga, Ba and Tl analyzed in this work. The concentrations of the remaining elements obtained by the multi-element analysis agree well with those certified. (orig.)

  3. Gamma-spectrometric and total alpha-beta counting methods for radioactivity analysis of deuterium depleted water

    International Nuclear Information System (INIS)

    Ferdes, Ov. S.; Mladin, C.; Vladu, Mihaela; Bulubasa, G.; Bidica, N.

    2008-01-01

    According to national regulations, as well as to the EU directive on the quality of drinking water, the radionuclide concentrations represent some of the drinking water quality parameters. Among the most important radioactivity content parameters are: the total alpha and total beta concentration (Bq/l); K-40 content, and the gamma-nuclides volume activities. The paper presents the measuring methods for low-level total alpha and/or beta counting of volume samples, as well as the high-resolution gamma-ray spectrometric method used to measure the volume activity of nuclides in drinking water. These methods are applied to monitor the radioactivity content and quality of the QLARIVIA brand of Deuterium depleted water (DDW). There are discussed the performances of these applied methods as well as some preliminary results. (authors)

  4. Standard test methods for chemical, mass spectrometric, and spectrochemical analysis of nuclear-grade plutonium dioxide powders and pellets

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 These test methods cover procedures for the chemical, mass spectrometric, and spectrochemical analysis of nuclear-grade plutonium dioxide powders and pellets to determine compliance with specifications. 1.2 The analytical procedures appear in the following order: Sections Plutonium Sample Handling 8 to 10 Plutonium by Controlled-Potential Coulometry Plutonium by Ceric Sulfate Titration Plutonium by Amperometric Titration with Iron(II) Plutonium by Diode Array Spectrophotometry Nitrogen by Distillation Spectrophotometry Using Nessler Reagent 11 to 18 Carbon (Total) by Direct Combustion–Thermal Conductivity 19 to 30 Total Chlorine and Fluorine by Pyrohydrolysis 31 to 38 Sulfur by Distillation Spectrophotometry 39 to 47 Plutonium Isotopic Analysis by Mass Spectrometry Rare Earth Elements by Spectroscopy 48 to 55 Trace Elements by Carrier–Distillation Spectroscopy 56 to 63 Impurities by ICP-AES Impurity Elements by Spark-Source Mass Spectrography 64 to 70 Moisture by the Coulomet...

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

    International Nuclear Information System (INIS)

    Chandola, L.C.; Khanna, P.P.

    1984-01-01

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

  6. A Double Slow Neutron Spectrometer; Spectrometre double pour neutrons lents; Dvojnoj spektrometr medlennykh nejtronov; Espectrometro doble para neutrones lentos

    Energy Technology Data Exchange (ETDEWEB)

    Bondarenko, I I; Liforov, V G; Nikolaev, M N; Orlov, V V; Parfenov, V A; Semenov, V A; Smirnov, V I; Turchin, V F [Fehi, Moscow, SSSR (Russian Federation)

    1963-01-15

    The neutron spectrometer described in the paper is intended for measurements of the angular and energy distribution of monochromatic slow neutrons, inelasticaily scattered by liquid and solid bodies. Experiments of this type permit detailed information to be obtained concerning the dynamics of the atoms in various aggregate states of a substance. The spectromeeter is based on the time-of-flight method. The pulse source of neutrons is the IBR (1) reactor. A mechanical interrupter, rotating synchronously with the disc of the IBR and having a prescribed phase shift, serves as the monochromator. A special phasing system ensures a phasee stability better than 0.5{sup o}. The neutrons scattered by the sample are recorded by a scintillation detector set at a given angle to the neutron beam. The resolving power of the spectrometer is - 15 {mu}s/m. The paper gives a detailed description of the construction of the spectroscope and its characteristics. (author) [French] Le spectrometre neutronique decrit dans le memoire est destine a mesurer la distribution en energie, la distribution angulaire et la diffusion inelastique des neutrons lents monochromatiques dans des liquides et des solides. Les experiences de ce genre permettent d'obtenir des renseignements detailles sur la dynamique des atomes dans de divers etats de la matiere. Le spectrometre est fonde sur la mesure du temps de vol. Comme source puisee de neutrons on a utilise le reacteur IBR-1. Le systeme monochromateur etait constitue par un interrupteur mecanique en rotation synchronisee avec celle du disque du reacteur IBR, avec un dephasage determine. Un dispositif special de dephasage assure la stabilite de la phase a 0,5{sup o} pres. La diffusion des neutrons par l'echantillon est enregistree a l'aide d'un detecteur a scintillations dispose sous un angle determine par rapport au faisceau de neutrons. Le pouvoir de resolution du spectrometre est d'environ 15 {mu}s/m. Les auteurs decrivent en detail la construction du

  7. Development of a mass spectrometrical isotope dilution analysis for determination of trace iodine levels and its application for food samples

    International Nuclear Information System (INIS)

    Schindlmeier, W.

    1984-01-01

    A mass spectrometrical isotope dilution procedure for the determination of trace amounts of iodine in various materials was developed using 129 I as indicator isotope, based on the determination of the 129 I/ 127 I isotope relationship. Negative thermionization was used as ionization method. The analysis procedure, which worked with a standard deviation of between 0,1 and 10% (depending on material tested), was used to determine the iodine level of table salt - both iodized and normal salt (3-6 ppm and less than 0,006 ppm respectively), and food samples with an organic matrix. For comparison the iodine levels were also measured with an iodine-selective electrode. Special preparation and separation procedures were done to suit the sample material. A comparison of the levels of iodine concentration in various powdered milks which were measured by international collaborators using varying methods shows the superior reproducibility of the MS-IDA. (RB) [de

  8. Standard test methods for chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of nuclear-grade uranyl nitrate solutions

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1999-01-01

    1.1 These test methods cover procedures for the chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of nuclear-grade uranyl nitrate solution to determine compliance with specifications. 1.2 The analytical procedures appear in the following order: Sections Determination of Uranium 7 Specific Gravity by Pycnometry 15-20 Free Acid by Oxalate Complexation 21-27 Determination of Thorium 28 Determination of Chromium 29 Determination of Molybdenum 30 Halogens Separation by Steam Distillation 31-35 Fluoride by Specific Ion Electrode 36-42 Halogen Distillate Analysis: Chloride, Bromide, and Iodide by Amperometric Microtitrimetry 43 Determination of Chloride and Bromide 44 Determination of Sulfur by X-Ray Fluorescence 45 Sulfate Sulfur by (Photometric) Turbidimetry 46 Phosphorus by the Molybdenum Blue (Photometric) Method 54-61 Silicon by the Molybdenum Blue (Photometric) Method 62-69 Carbon by Persulfate Oxidation-Acid Titrimetry 70 Conversion to U3O8 71-74 Boron by ...

  9. Standard test methods for chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of nuclear-grade plutonium nitrate solutions

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 These test methods cover procedures for the chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of nuclear-grade plutonium nitrate solutions to determine compliance with specifications. 1.2 The analytical procedures appear in the following order: Sections Plutonium by Controlled-Potential Coulometry Plutonium by Amperometric Titration with Iron(II) Plutonium by Diode Array Spectrophotometry Free Acid by Titration in an Oxalate Solution 8 to 15 Free Acid by Iodate Precipitation-Potentiometric Titration Test Method 16 to 22 Uranium by Arsenazo I Spectrophotometric Test Method 23 to 33 Thorium by Thorin Spectrophotometric Test Method 34 to 42 Iron by 1,10-Phenanthroline Spectrophotometric Test Method 43 to 50 Impurities by ICP-AES Chloride by Thiocyanate Spectrophotometric Test Method 51 to 58 Fluoride by Distillation-Spectrophotometric Test Method 59 to 66 Sulfate by Barium Sulfate Turbidimetric Test Method 67 to 74 Isotopic Composition by Mass Spectrom...

  10. Mass spectrometer introduction line: application to the analysis of impurities in uranium hexafluoride; Ligne d'introduction pour spectrometre de masse: application a l'analyse des impuretes contenues dans l'UF{sub 6}

    Energy Technology Data Exchange (ETDEWEB)

    Besson, M. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires. Departement de physico-chimie, service des isotopes stables, section de spectrometrie de masse

    1967-01-01

    The continuous mass-spectrometric analysis of impurities in UF{sub 6} is possible industrially if certain conditions imposed by the nature of the gas are respected. The gas introduction line arriving at the spectrometer's source makes it possible to fix the flow-rate, to control the inlet pressure and to selectively destroy the gas containing the impurities. The operational conditions for the line are defined and a description is given of the theoretical and experimental study of the various elements of which it is composed, i.e. the leak valve, the flow-meter, the chemical trap and the servo-mechanism making it possible to regulate and control the gas flow. The dynamic characteristics of the line's various components and the performance of the equipment in the case of the analyses considered are given. (author) [French] L'analyse en continu par spectrometrie de masse des impuretes contenus dans l'UF{sub 6} est possible industriellement moyennant certaines conditions imposees par la nature du gaz. La ligne d'introduction des gaz dans la source du spectrometre permet de regler le debit, de controler la pression d'introduction et de detruire selectivement le gaz porteur d'impuretes. Les conditions de fonctionnement de la ligne etant definies, on decrit l'etude theorique et experimentale des differents elements qui la composent, c'est-a-dire: le robinet a fuite, le debitmetre, le piege chimique et l'ensemble d'asservissement permettant la regulation et le controle du debit. On donne les caracteristiques dynamiques des differents constituants de la ligne et les performances de l'ensemble pour les analyses considerees. (auteur)

  11. Mass spectrometer introduction line: application to the analysis of impurities in uranium hexafluoride; Ligne d'introduction pour spectrometre de masse: application a l'analyse des impuretes contenues dans l'UF{sub 6}

    Energy Technology Data Exchange (ETDEWEB)

    Besson, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires. Departement de physico-chimie, service des isotopes stables, section de spectrometrie de masse

    1967-01-01

    The continuous mass-spectrometric analysis of impurities in UF{sub 6} is possible industrially if certain conditions imposed by the nature of the gas are respected. The gas introduction line arriving at the spectrometer's source makes it possible to fix the flow-rate, to control the inlet pressure and to selectively destroy the gas containing the impurities. The operational conditions for the line are defined and a description is given of the theoretical and experimental study of the various elements of which it is composed, i.e. the leak valve, the flow-meter, the chemical trap and the servo-mechanism making it possible to regulate and control the gas flow. The dynamic characteristics of the line's various components and the performance of the equipment in the case of the analyses considered are given. (author) [French] L'analyse en continu par spectrometrie de masse des impuretes contenus dans l'UF{sub 6} est possible industriellement moyennant certaines conditions imposees par la nature du gaz. La ligne d'introduction des gaz dans la source du spectrometre permet de regler le debit, de controler la pression d'introduction et de detruire selectivement le gaz porteur d'impuretes. Les conditions de fonctionnement de la ligne etant definies, on decrit l'etude theorique et experimentale des differents elements qui la composent, c'est-a-dire: le robinet a fuite, le debitmetre, le piege chimique et l'ensemble d'asservissement permettant la regulation et le controle du debit. On donne les caracteristiques dynamiques des differents constituants de la ligne et les performances de l'ensemble pour les analyses considerees. (auteur)

  12. Detection, characterization and quantification of salicylic acid conjugates in plant extracts by ESI tandem mass spectrometric techniques.

    Science.gov (United States)

    Pastor, Victoria; Vicent, Cristian; Cerezo, Miguel; Mauch-Mani, Brigitte; Dean, John; Flors, Victor

    2012-04-01

    An approach for the detection and characterization of SA derivatives in plant samples is presented based on liquid chromatography coupled to electrospray ionization (ESI) tandem mass spectrometric techniques. Precursor ion scan methods using an ESI triple quadrupole spectrometer for samples from plants challenged with the virulent Pseudomonas syringae pv tomato DC3000 allowed us to detect two potential SA derivatives. The criterion used to consider a potential SA derivative is based on the detection of analytes in the precursor ion scan chromatogram upon selecting m/z 137 and m/z 93 that correspond to the salicylate and its main product ion, respectively. Product ion spectra of the newly-detected analytes as well as accurate m/z determinations using an ESI Q-time-of-flight instrument were registered as means of characterization and strongly suggest that glucosylated forms of SA at the carboxylic and at the phenol functional groups are present in plant samples. The specific synthesis and subsequent chromatography of salicylic glucosyl ester (SGE) and glucosyl salicylate (SAG) standards confirmed the chemical identity of both peaks that were obtained applying different tandem mass spectrometric techniques and accurate m/z determinations. A multiple reaction monitoring method has been developed and applied to plant samples. The advantages of this LC-ESI-MS/MS methods with respect to the traditional analysis of glucosyl conjugates are also discussed. Preliminary results revealed that SA and the glucosyl conjugates are accumulated in Arabidopsis thaliana in a time dependent manner, accordingly to the up-regulation of SA-dependent defenses following P. syringae infection. This technique applied to plant hormones or fragment ions may be useful to obtain chemical family members of plant metabolites and help identify their contribution in the signaling of plant defenses. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  13. Forensic Drug Identification, Confirmation, and Quantification Using Fully Integrated Gas Chromatography with Fourier Transform Infrared and Mass Spectrometric Detection (GC-FT-IR-MS).

    Science.gov (United States)

    Lanzarotta, Adam; Lorenz, Lisa; Voelker, Sarah; Falconer, Travis M; Batson, JaCinta S

    2018-05-01

    This manuscript is a continuation of a recent study that described the use of fully integrated gas chromatography with direct deposition Fourier transform infrared detection and mass spectrometric detection (GC-FT-IR-MS) to identify and confirm the presence of sibutramine and AB-FUBINACA. The purpose of the current study was to employ the GC-FT-IR portion of the same instrument to quantify these compounds, thereby demonstrating the ability to identify, confirm, and quantify drug substances using a single GC-FT-IR-MS unit. The performance of the instrument was evaluated by comparing quantitative analytical figures of merit to those measured using an established, widely employed method for quantifying drug substances, high performance liquid chromatography with ultraviolet detection (HPLC-UV). The results demonstrated that GC-FT-IR was outperformed by HPLC-UV with regard to sensitivity, precision, and linear dynamic range (LDR). However, sibutramine and AB-FUBINACA concentrations measured using GC-FT-IR were not significantly different at the 95% confidence interval compared to those measured using HPLC-UV, which demonstrates promise for using GC-FT-IR as a semi-quantitative tool at the very least. The most significant advantage of GC-FT-IR compared to HPLC-UV is selectivity; a higher level of confidence regarding the identity of the analyte being quantified is achieved using GC-FT-IR. Additional advantages of using a single GC-FT-IR-MS instrument for identification, confirmation, and quantification are efficiency, increased sample throughput, decreased consumption of laboratory resources (solvents, chemicals, consumables, etc.), and thus cost.

  14. A Sensitive and Robust Ultra HPLC Assay with Tandem Mass Spectrometric Detection for the Quantitation of the PARP Inhibitor Olaparib (AZD2281 in Human Plasma for Pharmacokinetic Application

    Directory of Open Access Journals (Sweden)

    Jeffrey Roth

    2014-06-01

    Full Text Available Olaparib (AZD2281 is an orally active PARP-1 inhibitor, primarily effective against cancers with BRCA1/2 mutations. It is currently in Phase III development and has previously been investigated in numerous clinical trials, both as a single agent and in combination with chemotherapy. Despite this widespread testing, there is only one published method that provides assay details and stability studies for olaparib alone. A more sensitive uHPLC-MS/MS method for the quantification of olaparib in human plasma was developed, increasing the range of quantification at both ends (0.5–50,000 ng/mL compared to previously published methods (10–5,000 ng/mL. The wider range encompasses CMAX levels produced by typical olaparib doses and permits better pharmacokinetic modeling of olaparib elimination. This assay also utilizes a shorter analytical runtime, allowing for more rapid quantification and reduced use of reagents. A liquid-liquid extraction was followed by chromatographic separation on a Waters UPLC® BEH C18 column (2.1 × 50 mm, 1.7 µm and mass spectrometric detection. The mass transitions m/z 435.4→281.1 and m/z 443.2→281.1 were used for olaparib and the internal standard [2H8]-olaparib, respectively. The assay proved to be accurate (<9% deviation and precise (CV < 11%. Stability studies showed that olaparib is stable at room temperature for 24 h. in whole blood, at 4 °C for 24 h post-extraction, at −80 °C in plasma for at least 19 months, and through three freeze-thaw cycles. This method proved to be robust for measuring olaparib levels in clinical samples from a Phase I trial.

  15. Matrix-assisted laser desorption/ionization mass spectrometric imaging for the rapid segmental analysis of methamphetamine in a single hair using umbelliferone as a matrix.

    Science.gov (United States)

    Wang, Hang; Wang, Ying

    2017-07-04

    Segmental hair analysis offers a longer period for retrospective drug detection than blood or urine. Hair is a keratinous fiber and is strongly hydrophobic. The embedding of drugs in hydrophobic hair at low concentrations makes it difficult for extraction and detection with matrix-assisted laser desorption/ionization (MALDI) coupled with mass spectrometric imaging (MSI). In this study, a single scalp hair was longitudinally cut with a cryostat section to a length of 4 mm and fixed onto a stainless steel MALDI plate. Umbelliferone was used as a new hydrophobic matrix to enrich and assist the ionization efficiency of methamphetamine in the hair sample. MALDI-Fourier transform ion cyclotron resonance (FTICR)-MS profiling and imaging were performed for direct detection and mapping of methamphetamine on the longitudinal sections of the single hair sample in positive ion mode. Using MALDI-MSI, the distribution of methamphetamine was observed throughout five longitudinally sectioned hair samples from a drug abuser. The changes of methamphetamine were also semi-quantified by comparing the ratios of methamphetamine/internal standard (I.S). This method improves the detection sensitivity of target drugs embedded in a hair matrix for imaging with mass spectrometry. The method could provide a detection level of methamphetamine down to a nanogram per milligram incorporated into hair. The results were also compared with the conventional high performance liquid chromatography -tandem mass spectrometry (HPLC-MS/MS) method. Changes in the imaging results over time by the MSI method showed good semi-quantitative correlation to the results from the HPLC-MS/MS method. This study provides a powerful tool for drug abuse control and forensic medicine analysis in a narrow time frame, and a reduction in the sample amount required. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Matrix-assisted laser-desorption/ionization mass spectrometric imaging of olanzapine in a single hair using esculetin as a matrix.

    Science.gov (United States)

    Wang, Hang; Wang, Ying; Wang, Ge; Hong, Lizhi

    2017-07-15

    Matrix-assisted laser desorption/ionization-mass spectrometric imaging (MALDI-MSI) for the analysis of intact hair is a powerful tool for monitoring changes in drug consumption. The embedding of a low drug concentration in the hydrophobic hair matrix makes it difficult to extract and detect, and requires an improved method to increase detection sensitivity. In this study, an MSI method using MALDI-Fourier transform ion cyclotron resonance was developed for direct identification and imaging of olanzapine in hair samples using the positive ion mode. Following decontamination, scalp hair samples from an olanzapine user were scraped from the proximal to the distal end three times, and 5mm hair sections were fixed onto an Indium-Tin-Oxide (ITO)-coated microscopic glass slide. Esculetin (6,7-dihydroxy-2H-chromen-2-one) was used as a new hydrophobic matrix to increase the affinity, extraction and ionization efficiency of olanzapine in the hair samples. The spatial distribution of olanzapine was observed using five single hairs from the same drug user. This matrix improves the affinity of olanzapine in hair for molecular imaging with mass spectrometry. This method may provide a detection power for olanzapine to the nanogram level per 5mm hair. Time course changes in the MSI results were also compared with quantitative HPLC-MS/MS for each 5mm segment of single hair shafts selected from the MALDI target. MALDI imaging intensities in single hairs showed good semi-quantitative correlation with the results from conventional HPLC-MS/MS. MALDI-MSI is suitable for monitoring drug intake with a high time resolution. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Electrospray ionization mass spectrometric investigations of the complexation behavior of macrocyclic thiacrown ethers with bivalent transitional metals (Cu, Co, Ni and Zn).

    Science.gov (United States)

    Tsybizova, Alexandra; Tarábek, Ján; Buchta, Michal; Holý, Petr; Schröder, Detlef

    2012-10-15

    Heavy metals are both a problem for the environment and an important resource for industry. Their selective extraction by means of organic ligands therefore is an attractive topic. The coordination of three thiacrown ethers to late 3d-metal ions was investigated by a combination of electrospray ionization mass spectrometry (ESI-MS) and electron paramagnetic resonance (EPR). The mass spectrometric experiments were carried out in an ion trap mass spectrometer with an ESI source. Absolute binding constants were estimated by comparison with data for 18-crown-6/Na(+). EPR spectroscopy was used as a complementary method for investigating the Cu(I) /Cu(II) redox couple. The study found that thiacrown ethers preferentially bind traces of copper even at an excess of other metal ions (Co(II), Ni(II), and Zn(II)). The absolute association constants of the Cu(I) complexes were about 10(8) M(-1), and about two orders of magnitude lower for the other 3d-metal cations. The EPR spectra demonstrated that the reduction from Cu(II) to Cu(I) upon formation of the [(thiacrown)Cu](+) species takes place in solution. ESI-MS demonstrated that the three thiacrown ligands examined had high binding constants as well as good selectivities for copper(I) at low concentrations, and in the presence of other metal ions. By a combination of ESI-MS and EPR spectrometry it was shown that the reduction from Cu(II) to Cu(I) occurred in solution. Copyright © 2012 John Wiley & Sons, Ltd.

  18. Evaluation of errors for mass-spectrometric analysis with surface-ionization type mass-spectrometer (statistical evaluation of mass-discrimination effect)

    International Nuclear Information System (INIS)

    Wada, Y.

    1981-01-01

    The surface-ionization type mass-spectrometer is widely used as an apparatus for quality assurance, accountability and safeguarding of nuclear materials, and for this analysis it has become an important factor to statistically evaluate an analytical error which consists of a random error and a systematic error. The major factor of this systematic error was the mass-discrimination effect. In this paper, various assays for evaluating the factor of variation on the mass-discrimination effect were studied and the data obtained were statistically evaluated. As a result of these analyses, it was proved that the factor of variation on the mass-discrimination effect was not attributed to the acid concentration of sample, sample size on the filament and supplied voltage for a multiplier, but mainly to the filament temperature during the mass-spectrometric analysis. The mass-discrimination effect values β which were usually calculated from the measured data of uranium, plutonium or boron isotopic standard sample were not so significant dependently of the difference of U-235, Pu-239 or B-10 isotopic abundance. Furthermore, in the case of U and Pu, measurement conditions and the mass range of these isotopes were almost similar, and these values β were not statistically significant between U and Pu. On the other hand, the value β for boron was about a third of the value β for U or Pu, but compared with the coefficient of the correction on the mass-discrimination effect for the difference of mass-number, ΔM, these coefficient values were almost the same among U, Pu, and B.As for the isotopic analysis error of U, Pu, Nd and B, it was proved that the isotopic abundance of these elements and the isotopic analysis error were in a relationship of quadratic curves on a logarithmic-logarithmic scale

  19. Gamma-spectrometric surveys in differentiated granites. I: a review of the method and of the geochemical behavior of K, Th and U; Levantamentos gamaespectrometricos em granitos diferenciados. I: revisao da metodologia e do comportamento geoquimico dos elementos K, Th e U

    Energy Technology Data Exchange (ETDEWEB)

    Ulbrich, Horstpeter Herberto Gustavo Jose; Ulbrich, Mabel Norma Costas [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Geociencias. Dept. de Mineralogia e Geotectonica], e-mail: hulbrich@usp.br, e-mail: mulbrich@usp.br; Ferreira, Francisco Jose Fonseca [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Geologia. Lab. de Pesquisas em Geofisica Aplicada; Alves, Luizemara Soares [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)], e-mail: luizemara@petrobras.com.br; Guimaraes, Gilson Burigo [Universidade Estadual de Ponta Grossa (UEPG), PR (Brazil). Dept. de Geociencias], e-mail: gburigo@ig.com.br; Fruchting, Allan [Votorantim Metais, Sao Paulo, SP (Brazil)], e-mail: allan.fruchting@vmetais.com.br

    2009-07-01

    This contribution is part of a research project on the Neo proterozoic Cunhaporanga Granitic Complex (CGC), cropping out in the Ponta Grossa Arch (Parana state, SE Brazil). An initial study used the gamma-spectrometric data of the Serra do Mar Sul Aero geophysical Project, performed during the 70's for CPRM. Later, terrestrial gamma-spectrometric surveys focused on the study of the differentiated Joaquim Murtinho Granite (JMG) in the NW corner of CGC, and the Serra do Carambei Granite, to the SW. In this paper, the results obtained for JMG are presented in two parts. The first deals with methodology and the presentation of several gamma-spectrometric 'color-scale' maps, indicating that results obtained in granites depend strongly on a climatic factor, given the mobility of K during weathering in subtropical climates with strong rainfalls, also favoring a greater mobility of U. Minerals that are U and Th hosts, documented in granites, are reviewed, together with the weathering processes that control the mobility of K, U and Th in soils. Strong K signals in granitic areas submitted to these climates document the presence of fresh rock and/or effects of hydrothermal alteration, while weak or nil signals are evidence of strong leaching of K during weathering. U and Th will be retained in the residual soils, in part leading to their selective enrichment, also coupled with soil migration to lower topographic levels by colluvial transport. The larger solubility of U (as uranyl ion) allows its liberation under oxidizing conditions, and its migration, limited by the possibility of absorption in newly formed mineral and organic soil phases. Th should be retained almost totally in resistant phases and, when liberated in solution, will mostly be fixed in organic and inorganic soil substances. (author)

  20. Application of gas chromatography, mass spectrometry analysis to the study of works of art. Paint media identification in polychrome multi-material sculptures

    Energy Technology Data Exchange (ETDEWEB)

    Casoli, A.; Vizzari, M. [Parma Univ., Parma (Italy). Dipt. di Chimica Generale ed Inorganica, Chimica Analitica, Chimica Fisica; Cremonesi, P. [Chemist and Conservator, Cornegliano Laudense, Lodi (Italy); Palla, G. [Parma Univ., Parma (Italy). Dipt. di Chimica Organica e Industriale

    2001-12-01

    A new gas chromatographic-mass spectrometric procedure for characterizing both drying oil and proteinaceous binders in samples of painted artworks has been developed. Furthermore, a new analytical procedure for analysis of polysaccharide materials through identification of the monosaccharide constituents is proposed. The methods have been applied to characterize binding media of the different layers of the polychrome surface in the multi-material sculptures from the sanctuary of 'S. Maria delle Grazie in Mantova', Italy. It was found that animal glue was the main binder in the priming layer of all statues, whereas more complex mixtures were used in the paint layers. Generally, a drying oil was present, most often linseed oil alone or in combination with other organic binders. [Italian] Si propone una nuova procedura analitica, mediante gascromatografia/spettrometria di massa, rivolta alla caratterizzazione di oli siccativi e leganti proteici presenti in un unico campione di materiale pittorico derivante da un'opera d'arte. Si descrive, inoltre, un nuovo metodo gascromatografico per l'analisi di materiale polisaccaridico, mediante l'identificazione dei suoi componenti. I metodi analitici sono stati impiegati per la caratterizzazione del legante pittorico dei differenti strati costituenti la policromia di sculture polimateriche conservate presso il Santuario di Santa Maria delle Grazie in Mantova. E' stato riscontrato che per tutte le statue, il legante principale degli strati di preparazione del colore era colla animale, mentre , si e' osservato, inoltre, che gli strati pittorici hanno previsto, per la loro stesura, l'impiego di miscele complesse di sostanze organiche. Principalmente e' stata riscontrata la presenza di olio di lino, impiegato sia come unico legante sia in combinazione con altri.

  1. Development of spectrometric probes for emergency preparedness. Status and way forward; Entwicklung von spektrometrierenden Sonden fuer den Notfallschutz. Stand und Perspektiven

    Energy Technology Data Exchange (ETDEWEB)

    Zaehringer, M.; Bleher, M. [Bundesamt fuer Strahlenschutz (BfS), Salzgitter (Germany); Dambacher, M. [X-Ray Imaging Europe, Freiburg (Germany); and others

    2014-01-20

    Spectrometric probes with medium energy resolution (NaI, LaBr{sub 3}, CZT) have the potential to enhance existing gamma dose rate monitoring networks as a early warning system by increasing the sensitivity and specificity. In an emergency situation nuclide specific information with sufficient spatial resolution can be made available to decision makers. An ongoing research project between BfS and the Freiburg Material Research Centre (FMF) aims at the development of semiconductor detectors based on Cadmium-Zink-Telluride which can be used for low cost ruggedized spectrometric systems suitable for deployment in an environmental network. The new probe contains also a newly developed versatile multi channel analyser. The system has a modular design and is based - where ever possible - on open source components. It is complemented by specific analysis software using established data exchange formats. This facilitates international cooperation and exploits synergies through distributed development of components.

  2. One Sample, One Shot - Evaluation of sample preparation protocols for the mass spectrometric proteome analysis of human bile fluid without extensive fractionation.

    Science.gov (United States)

    Megger, Dominik A; Padden, Juliet; Rosowski, Kristin; Uszkoreit, Julian; Bracht, Thilo; Eisenacher, Martin; Gerges, Christian; Neuhaus, Horst; Schumacher, Brigitte; Schlaak, Jörg F; Sitek, Barbara

    2017-02-10

    The proteome analysis of bile fluid represents a promising strategy to identify biomarker candidates for various diseases of the hepatobiliary system. However, to obtain substantive results in biomarker discovery studies large patient cohorts necessarily need to be analyzed. Consequently, this would lead to an unmanageable number of samples to be analyzed if sample preparation protocols with extensive fractionation methods are applied. Hence, the performance of simple workflows allowing for "one sample, one shot" experiments have been evaluated in this study. In detail, sixteen different protocols implying modifications at the stages of desalting, delipidation, deglycosylation and tryptic digestion have been examined. Each method has been individually evaluated regarding various performance criteria and comparative analyses have been conducted to uncover possible complementarities. Here, the best performance in terms of proteome coverage has been assessed for a combination of acetone precipitation with in-gel digestion. Finally, a mapping of all obtained protein identifications with putative biomarkers for hepatocellular carcinoma (HCC) and cholangiocellular carcinoma (CCC) revealed several proteins easily detectable in bile fluid. These results can build the basis for future studies with large and well-defined patient cohorts in a more disease-related context. Human bile fluid is a proximal body fluid and supposed to be a potential source of disease markers. However, due to its biochemical composition, the proteome analysis of bile fluid still represents a challenging task and is therefore mostly conducted using extensive fractionation procedures. This in turn leads to a high number of mass spectrometric measurements for one biological sample. Considering the fact that in order to overcome the biological variability a high number of biological samples needs to be analyzed in biomarker discovery studies, this leads to the dilemma of an unmanageable number of

  3. Site-Specific Hydrogen Isotope Composition of Propane: Mass spectrometric methods, equilibrium temperature dependence, and kinetics of exchange

    Science.gov (United States)

    Xie, H.; Ponton, C.; Kitchen, N.; Lloyd, M. K.; Lawson, M.; Formolo, M. J.; Eiler, J. M.

    2016-12-01

    -specific thermometer; these experiments also provide a reference frame for reporting mass spectrometric data. Differential H-exchange rates of the two molecular sites in propane could be a new tool to constrain thermal history of sub-surface propane. Our experimental and mass spectrometric approaches should be generalizable to other hydrocarbon compounds.

  4. Dansyl-peptides matrix-assisted laser desorption/ionization mass spectrometric (MALDI-MS) and tandem mass spectrometric (MS/MS) features improve the liquid chromatography/MALDI-MS/MS analysis of the proteome.

    Science.gov (United States)

    Chiappetta, Giovanni; Ndiaye, Sega; Demey, Emmanuelle; Haddad, Iman; Marino, Gennaro; Amoresano, Angela; Vinh, Joëlle

    2010-10-30

    Peptide tagging is a useful tool to improve matrix-assisted laser desorption/ionization tandem mass spectrometric (MALDI-MS/MS) analysis. We present a new application of the use of the dansyl chloride (DNS-Cl). DNS-Cl is a specific primary amine reagent widely used in protein biochemistry. It adds a fluorescent dimethylaminonaphthalene moiety to the molecule. The evaluation of MALDI-MS and MS/MS analyses of dansylated peptides shows that dansylation raises the ionization efficiency of the most hydrophilic species compared with the most hydrophobic ones. Consequently, higher Mascot scores and protein sequence coverage are obtained by combining MS and MS/MS data of native and tagged samples. The N-terminal DNS-Cl sulfonation improves the peptide fragmentation and promotes the generation of b-fragments allowing better peptide sequencing. In addition, we set up a labeling protocol based on the microwave chemistry. Peptide dansylation proved to be a rapid and cheap method to improve the performance of liquid chromatography (LC)/MALDI-MS/MS analysis at the proteomic scale in terms of peptide detection and sequence coverage. Copyright © 2010 John Wiley & Sons, Ltd.

  5. Mass Spectrometric Analyses Reveal a Central Role for Ubiquitylation in Remodeling the Arabidopsis Proteome during Photomorphogenesis.

    Science.gov (United States)

    Aguilar-Hernández, Victor; Kim, Do-Young; Stankey, Robert J; Scalf, Mark; Smith, Lloyd M; Vierstra, Richard D

    2017-06-05

    The switch from skotomorphogenesis to photomorphogenesis is a key developmental transition in the life of seed plants. While much of the underpinning proteome remodeling is driven by light-induced changes in gene expression, the proteolytic removal of specific proteins by the ubiquitin-26S proteasome system is also likely paramount. Through mass spectrometric analysis of ubiquitylated proteins affinity-purified from etiolated Arabidopsis seedlings before and after red-light irradiation, we identified a number of influential proteins whose ubiquitylation status is modified during this switch. We observed a substantial enrichment for proteins involved in auxin, abscisic acid, ethylene, and brassinosteroid signaling, peroxisome function, disease resistance, protein phosphorylation and light perception, including the phytochrome (Phy) A and phototropin photoreceptors. Soon after red-light treatment, PhyA becomes the dominant ubiquitylated species, with ubiquitin attachment sites mapped to six lysines. A PhyA mutant protected from ubiquitin addition at these sites is substantially more stable in planta upon photoconversion to Pfr and is hyperactive in driving photomorphogenesis. However, light still stimulates ubiquitylation and degradation of this mutant, implying that other attachment sites and/or proteolytic pathways exist. Collectively, we expand the catalog of ubiquitylation targets in Arabidopsis and show that this post-translational modification is central to the rewiring of plants for photoautotrophic growth. Copyright © 2017 The Author. Published by Elsevier Inc. All rights reserved.

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

    Science.gov (United States)

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

    1979-01-01

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

  7. Standard test methods for chemical, mass spectrometric, and spectrochemical analysis of nuclear-grade uranium dioxide powders and pellets

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1999-01-01

    1.1 These test methods cover procedures for the chemical, mass spectrometric, and spectrochemical analysis of nuclear-grade uranium dioxide powders and pellets to determine compliance with specifications. 1.2 This test method covers the determination of uranium and the oxygen to uranium atomic ratio in nuclear-grade uranium dioxide powder and pellets. 1.4 This test method covers the determination of chlorine and fluorine in nuclear-grade uranium dioxide. With a 1 to 10-g sample, concentrations of 5 to 200 g/g of chlorine and 1 to 200 μg/g of fluorine are determined without interference. 1.5 This test method covers the determination of moisture in uranium dioxide samples. Detection limits are as low as 10 μg. 1.6 This test method covers the determination of nitride nitrogen in uranium dioxide in the range from 10 to 250 μg. 1.7 This test method covers the spectrographic analysis of nuclear-grade UO2 for the 26 elements in the ranges indicated in Table 2. 1.8 For simultaneous determination of trace ele...

  8. Mono-, di- and trimethylated homologues of isoprenoid tetraether lipid cores in archaea and environmental samples: mass spectrometric identification and significance.

    Science.gov (United States)

    Knappy, Chris; Barillà, Daniela; Chong, James; Hodgson, Dominic; Morgan, Hugh; Suleman, Muhammad; Tan, Christine; Yao, Peng; Keely, Brendan

    2015-12-01

    Higher homologues of widely reported C(86) isoprenoid diglycerol tetraether lipid cores, containing 0-6 cyclopentyl rings, have been identified in (hyper)thermophilic archaea, representing up to 21% of total tetraether lipids in the cells. Liquid chromatography-tandem mass spectrometry confirms that the additional carbon atoms in the C(87-88) homologues are located in the etherified chains. Structures identified include dialkyl and monoalkyl ('H-shaped') tetraethers containing C(40-42) or C(81-82) hydrocarbons, respectively, many representing novel compounds. Gas chromatography-mass spectrometric analysis of hydrocarbons released from the lipid cores by ether cleavage suggests that the C(40) chains are biphytanes and the C(41) chains 13-methylbiphytanes. Multiple isomers, having different chain combinations, were recognised among the dialkyl lipids. Methylated tetraethers are produced by Methanothermobacter thermautotrophicus in varying proportions depending on growth conditions, suggesting that methylation may be an adaptive mechanism to regulate cellular function. The detection of methylated lipids in Pyrobaculum sp. AQ1.S2 and Sulfolobus acidocaldarius represents the first reported occurrences in Crenarchaeota. Soils and aquatic sediments from geographically distinct mesotemperate environments that were screened for homologues contained monomethylated tetraethers, with di- and trimethylated structures being detected occasionally. The structural diversity and range of occurrences of the C(87-89) tetraethers highlight their potential as complementary biomarkers for archaea in natural environments. Copyright © 2015 John Wiley & Sons, Ltd.

  9. Mass spectrometric determination of magnesium isotopic ratios and its corrections for electron multiplier discrimination and mass fractionation

    International Nuclear Information System (INIS)

    Deng Zhongguo

    1989-01-01

    The mass spectrometric determination of magnesium isotopic ratios by the use of uranyl nitrate added to magnesium samples to act as a binding agent is reported. Prebaking empty filaments and preheating filaments with deposited magnesium samples on its surface in a vacuum are employed to reduce the Na signal from the thenium-ribbon. Methods for correcting magnesium isotopic ratios for electron multiplier discrimination and mass fractionation are described in detail. The results of the determination of natural magnesium isotopic ratios are 25 Mg/ 24 Mg = 0.12660 (1±0.01%) and 26 Mg/ 24 Mg = 0.13938 (1±0.10%). The magnesium isotopic ratios of rich - 26 Mg-2 sample and rich- 25 Mg-1 sample are 24 Mg/ 26 Mg = 0.003463 (1±0.2%), 25 Mg/ 26 Mg = 0.001656 (±0.2%) and 24 Mg/ 25 Mg = 0.006716 (1±0.2%), 26 Mg/ 25 Mg = 0.007264 (1±0.2%) respectively

  10. The IDA-80 measurement evaluation programme on mass spectrometric isotope dilution analysis of uranium and plutonium. Vol. 1

    International Nuclear Information System (INIS)

    Beyrich, W.; Golly, W.; Spannagel, G.; Kernforschungszentrum Karlsruhe G.m.b.H.; Bievre, P. de; Wolters, W.

    1984-12-01

    The main objective was the acquisition of basic data on the uncertainties involved in the mass spectrometric isotope dilution analysis as applied to the determination of uranium and plutonium in active feed solutions of reprocessing plants. The element concentrations and isotopic compositions of all test materials used were determined by CBNM and NBS with high accuracy. The more than 60000 analytical data reported by the participating laboratories were evaluated by statistical methods applied mainly to the calculation of estimates of the variances for the different uncertainty components contributing to the total uncertainty of this analytical technique. Attention was given to such topics as sample ageing, influence of fission products, spike calibration, ion fractionation, Pu-241 decay correction, minor isotope measurement and errors in data transfer. Furthermore, the performance of the 'dried sample' technique and the 'in-situ' spiking method of undiluted samples of reprocessing fuel solution with U-235/Pu-242 metal alloy spikes, were tested successfully. Considerable improvement of isotope dilution analysis in this safeguards relevant application during the last decade is shown as compared to the results obtained in the IDA-72 interlaboratory experiment, organized by KfK in 1972 on the same subject. (orig./HP) [de

  11. Cu2+-assisted two dimensional charge-mass double focusing gel electrophoresis and mass spectrometric analysis of histone variants.

    Science.gov (United States)

    Zhang, Wenyang; Tang, Xuemei; Ding, Mengjie; Zhong, Hongying

    2014-12-10

    Abundant isoforms and dynamic posttranslational modifications cause the separation and identification of histone variants to be experimentally challenging. To meet this need, we employ two-dimensional electrophoretic gel separation followed by mass spectrometric detection which takes advantage of the chelation of Cu(2+) with amino acid residues exposed on the surfaces of the histone proteins. Acid-extracted rat liver histones were first mixed with CuSO4 solution and then separated in one dimension with triton-acid-urea (TAU) gel electrophoresis and in a second dimension using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The separations result from both the changes in charge and mass upon Cu(2+) chelation. Identities of each separated gel bands were obtained by using matrix-assisted laser desorption-ionization mass spectrometry (MALDI-MS). It was found that the migration of H3 histone isoforms of rat liver is markedly affected by the use of Cu(2+) ions. Copyright © 2014 Elsevier B.V. All rights reserved.

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

    International Nuclear Information System (INIS)

    Jat, J.R.; Balaji Rao, Y.; Prasada Rao, G.; Prahlad, B.

    2012-01-01

    The present paper describes a method developed at Control Laboratory, NFC which includes prior separation of lithium and potassium from uranium matrix before their measurements. Solvent extraction, using Tri-n-Butyl Phosphate (TBP) in CCI 4 followed by Tri-n-Octyl Phosphine Oxide (TOPO) in CCI 4 , is employed for prior separation of Li and K. The resultant aqueous solution was analyzed by Flame-Atomic Emission Spectrometric (AES) method. Solvent extraction conditions are optimized for measurement of Li and K in the same aliquot. Experimental conditions such as instrument calibration, flame condition, fuel flow, sample flow rate through nebulizer, burner height etc. are also optimized. Under the optimal condition the detection limits achieved for lithium is 0.02 ppm and 0.2 ppm for potassium. A RSD of ± 3 % for Li at 0.05 ppm and ± 4% for K at 1 ppm level has been achieved in this method. The results of lithium in the sample are compared with the values obtained by Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES). Similarly, values of potassium are compared with Flame-Atomic Absorption Spectrometry (Flame-AAS) technique. The comparisons are in good agreement. The above method is simple, sensitive, reproducible and can be used for measurement of lithium and potassium in UO 2 powder and pellets on regular basis

  13. Analysis of small carbohydrates in several bioactive botanicals by gas chromatography with mass spectrometry and liquid chromatography with tandem mass spectrometry.

    Science.gov (United States)

    Moldoveanu, Serban; Scott, Wayne; Zhu, Jeff

    2015-11-01

    Bioactive botanicals contain natural compounds with specific biological activity, such as antibacterial, antioxidant, immune stimulating, and taste improving. A full characterization of the chemical composition of these botanicals is frequently necessary. A study of small carbohydrates from the plant materials of 18 bioactive botanicals is further described. The study presents the identification of the carbohydrate using a gas chromatographic-mass spectrometric analysis that allows detection of molecules as large as maltotetraose, after changing them into trimethylsilyl derivatives. A number of carbohydrates in the plant (fructose, glucose, mannose, sucrose, maltose, xylose, sorbitol, and myo-, chiro-, and scyllo-inositols) were quantitated using a novel liquid chromatography with tandem mass spectrometric technique. Both techniques involved new method developments. The gas chromatography with mass spectrometric analysis involved derivatization and separation on a Rxi(®)-5Sil MS column with H2 as a carrier gas. The liquid chromatographic separation was obtained using a hydrophilic interaction type column, YMC-PAC Polyamine II. The tandem mass spectrometer used an electrospray ionization source in multiple reaction monitoring positive ion mode with the detection of the adducts of the carbohydrates with Cs(+) ions. The validated quantitative procedure showed excellent precision and accuracy allowing the analysis in a wide range of concentrations of the analytes. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Stability of drugs of abuse in urine samples stored at -20 degrees C.

    Science.gov (United States)

    Dugan, S; Bogema, S; Schwartz, R W; Lappas, N T

    1994-01-01

    Isolated studies of the stability of individual drugs of abuse have been reported. However, few have evaluated stability in frozen urine samples stored for 12 months. We have determined the stability of 11-nor-9-carboxy-delta 9-tetrahydrocannabinol (9-COOH-THC), amphetamine, methamphetamine, morphine, codeine, cocaine, benzoylecgonine, and phencyclidine in 236 physiological urine samples. Following the initial quantitative analysis, the samples were stored at -20 degrees C for 12 months and then reanalyzed. All drug concentrations were determined by gas chromatographic-mass spectrometric methods with cutoff concentrations of 5 ng/mL for 9-COOH-THC and phencyclidine and 100 ng/mL for each of the other drugs. The average change in the concentrations of these drugs following this long-term storage was not extensive except for an average change of -37% in cocaine concentrations.

  15. Identification and quantification of flavonoids in human urine samples by column switching liquid chromatography coupled to atmospheric pressure chemical ionization mass spectrometry

    DEFF Research Database (Denmark)

    Nielsen, S. E.; Freese, R.; Cornett, Claus

    2000-01-01

    A rapid and sensitive high-performance liquid chromatographic mass spectrometric (HPLC-MS) method is described for the determination and quantification of 12 dietary flavonoid glycosides and aglycons in human urine samples. Chromatographic separation of the analytes of interest was achieved...... by column-switching, using the first column (a Zorbax 300SB C-3 column) for sample cleanup and eluting the heart-cut flavonoid fraction onto the second column (a Zorbax SE C-18 column) for separation and detection by ultraviolet and atmospheric pressure chemical ionization MS using single ion monitoring...... of variation for the analysis of the 12 different flavonoids in quality control urine samples were 12.3% on average (range 11.0-13.7%, n = 24, reproducibility) and the repeatability of the assay were 5.0% (mean, range 0.1-14.8%, it = 12). A subset of 10 urine samples from a human dietary intervention study...

  16. Mass spectrometry. [in organic chemistry

    Science.gov (United States)

    Burlingame, A. L.; Shackleton, C. H. L.; Howe, I.; Chizhov, O. S.

    1978-01-01

    A review of mass spectrometry in organic chemistry is given, dealing with advances in instrumentation and computer techniques, selected topics in gas-phase ion chemistry, and applications in such fields as biomedicine, natural-product studies, and environmental pollution analysis. Innovative techniques and instrumentation are discussed, along with chromatographic-mass spectrometric on-line computer techniques, mass spectral interpretation and management techniques, and such topics in gas-phase ion chemistry as electron-impact ionization and decomposition, photoionization, field ionization and desorption, high-pressure mass spectrometry, ion cyclotron resonance, and isomerization reactions of organic ions. Applications of mass spectrometry are examined with respect to bio-oligomers and their constituents, biomedically important substances, microbiology, environmental organic analysis, and organic geochemistry.

  17. A novel study of screening and confirmation of modafinil, adrafinil and their metabolite modafinilic acid under EI-GC-MS and ESI-LC-MS-MS ionization.

    Science.gov (United States)

    Dubey, S; Ahi, S; Reddy, I M; Kaur, T; Beotra, A; Jain, S

    2009-12-01

    Adrafinil and modafinil have received wide publicity and have become controversial in the sporting world when several athletes were discovered allegedly using these drugs as doping agents. By acknowledging the facts, the World Anti-Doping Agency (WADA) banned these drugs in sports since 2004. The present study explores the possibility of differentiating adrafinil and modafinil and their major metabolites under electron impact ionization in gas chromatograph-mass spectrometer (GC-MSD) and electrospray ionization in liquid chromatograph-mass spectrometer (LC-MS/MS) by studying the fragmentation pattern of these drugs. Adrafinil, modafinil and their major metabolite, modafinilic acid were analyzed on EI-GC-MSD and ESI-LC-MS/MS using various individual parameters on both the instruments. The analytical technique and equipment used in the analysis were an Agilent 6890N GC with 5973 mass selective detector for the GC-MSD analysis and an Agilent 1100 HPLC with API-3200 Triple quadrupole mass spectrometer for the LC-MS/MS analysis. Validation of both methods was performed using six replicates at different concentrations. The results show that adrafinil, modafinil and their major metabolite modafinilic acid could be detected as a single artifact without differentiation under EI-GC-MSD analysis. However, all drugs could be detected and differentiated under ESI-LCMS/MS analysis without any artifaction. The GC-MSD analysis gives a single artifact for both the drugs without differentiation and thus can be used as a marker for screening purposes. Further, the Multiple Reaction Monitoring (MRM) method developed under LC-MS/MS is fit for the purpose for confirmation of suspicious samples in routine sports testing and in forensic and clinical analysis.

  18. Mass Spectrometric Investigation of Silicon Extremely Enriched in (28)Si: From (28)SiF4 (Gas Phase IRMS) to (28)Si Crystals (MC-ICP-MS).

    Science.gov (United States)

    Pramann, Axel; Rienitz, Olaf

    2016-06-07

    A new generation of silicon crystals even further enriched in (28)Si (x((28)Si) > 0.999 98 mol/mol), recently produced by companies and institutes in Russia within the framework of a project initiated by PTB, were investigated with respect to their isotopic composition and molar mass M(Si). A modified isotope dilution mass spectrometric (IDMS) method treating the silicon as the matrix containing a so-called virtual element (VE) existing of the isotopes (29)Si and (30)Si solely and high resolution multicollector inductively coupled plasma mass spectrometry (MC-ICP-MS) were applied in combination. This method succeeds also when examining the new materials holding merely trace amounts of (29)Si (x((29)Si) ≈ 5 × 10(-6) mol/mol) and (30)Si (x((30)Si) ≈ 7 × 10(-7) mol/mol) extremely difficult to detect with lowest uncertainty. However, there is a need for validating the enrichment in (28)Si already in the precursor material of the final crystals, silicon tetrafluoride (SiF4) gas prior to crystal production. For that purpose, the isotopic composition of selected SiF4 samples was determined using a multicollector magnetic sector field gas-phase isotope ratio mass spectrometer. Contaminations of SiF4 by natural silicon due to storing and during the isotope ratio mass spectrometry (IRMS) measurements were observed and quantified. The respective MC-ICP-MS measurements of the corresponding crystal samples show-in contrast-several advantages compared to gas phase IRMS. M(Si) of the new crystals were determined to some extent with uncertainties urel(M) < 1 × 10(-9). This study presents a clear dependence of the uncertainty urel(M(Si)) on the degree of enrichment in (28)Si. This leads to a reduction of urel(M(Si)) during the past decade by almost 3 orders of magnitude and thus further reduces the uncertainty of the Avogadro constant NA which is one of the preconditions for the redefinition of the SI unit kilogram.

  19. Gamma-spectrometric surveys in differentiated granites. II: the Joaquim Murtinho Granite in the Cunhaporanga Granitic Complex, Parana, SE Brazil; Levantamentos gamaespectrometricos em granitos diferenciados. II: O exemplo do Granito Joaquim Murtinho, Complexo Granitico Cunhaporanga, Parana

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Francisco Jose Fonseca [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Geologia. Lab. de Pesquisas em Geofisica Aplicada; Fruchting, Allan [Votorantim Metais, Sao Paulo, SP (Brazil)], e-mail: allan.fruchting@vmetais.com.br; Guimaraes, Gilson Burigo [Universidade Estadual de Ponta Grossa (UEPG), PR (Brazil). Dept. de Geociencias], e-mail: gburigo@ig.com.br; Alves, Luizemara Soares [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)], e-mail: luizemara@petrobras.com.br; Martin, Victor Miguel Oliveira; Ulbrich, Horstpeter Herberto Gustavo Jose [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Geociencias. Dept. de Mineralogia e Geotectonica], e-mail: vicmartin6@ig.com.br, e-mail: hulbrich@usp.br

    2009-07-01

    Detailed mapping at the NW corner of the large Neo proterozoic Cunhaporanga Granitic Complex (CGC), Parana state, SE Brazil, redefined the Joaquim Murtinho Granite (JMG), a late intrusion in CGC with an exposed area of about 10 km{sup 2}, made up mainly by evolved 'alaskites' (alkali-feldspar leuco granites). This unit is in tectonic contact with the Neoproterozoic-Eocambrian volcano-sedimentary Castro Group, to the W, and is intrusive into other less evolved granitic units of the CGC to the E. Petrographically, JMG shows mainly mesoperthite and quartz, with subordinate amounts of altered micas and some accessory phases, mainly zircon. The equi to inequigranular granites are usually deformed with cataclastic textures, are often brecciated, and may have miarolitic structures. Formation of late albite, sericite, carbonate and hematite was caused by deuteric and hydrothermal alteration. A gamma-ray spectrometric survey at 231 stations which measured total counts (TC), Ueq K%, eU ppm and eTh ppm was used to construct several direct and derived maps. Compared to neighboring units the JMG has significant anomalies, especially in the TC, %K, eTh and eU maps, although the differences are less obvious in some derived maps. These evolved granites are enriched in these three elements. Geochemical behavior of K, Th and U is used to analyse the results observed in maps. Enhanced weathering under a subtropical climate with moderate to high average temperatures and heavy rainfall affects mainly feldspars and biotite, and may also destabilize most U and Th-bearing accessory phases. Th is most likely retained in restite minerals in soils, being relatively immobile, while part of U may migrate as uranyl ion in oxidizing media. K is especially affected by feldspar alteration to K-free clays (mainly kaolinite), and may be completely leached. Gamma-ray spectrometric methods are valid tools to study facies in granitic rocks, especially in those that are enriched in K, Th and U

  20. Electron multiplier for the measurement of an ion current on a mass spectrometer; Multiplicateur d'electrons pour la mesure de courant d'ions sur un spectrometre de masse

    Energy Technology Data Exchange (ETDEWEB)

    Lohez, P; Nief, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1957-07-01

    The apparatus described is designed to measure weak ion currents received at the collector of a mass spectrometer. The report describes successively the study of electron paths in the multiplier by the method of analogy, using rubber membranes, and the practical details of construction of the apparatus. The variation with surface treatment of the secondary emission coefficient of the alloy CuBe containing 2 per cent Be, which makes up the dynodes, and the influence of the voltage on the gain per stage, are discussed. Results of tests regarding: the influence of the ion mass on the gain, the background of the instrument and the energy distribution of the impulses coming out on a high gain multiplier (q.q. 10{sup 7}) are given. Finally the performances of the multiplier are reported. 1- For a low gain (10{sup 4}), precision and reproducibility comparable to the electrometer valve, sensitivity 100 times greater, currents capable of detection 10{sup -17} Ampere. 2- For a high gain (10{sup 7}) and measurement by impulse counting, currents capable of detection 10{sup -19} Ampere. Mounting difficult to use on a mass spectrometer. (author) [French] L'appareil decrit est destine a la mesure des faibles courants d'ions re s au collecteur d'un spectrometre de masse. Le rapport decrit successivement l'etude des trajectoires des electrons dans le multiplicateur, par la methode analogique de la menbrane en caoutchouc, et la realisation pratique de l'appareil. La variation du coefficient d'emission secondaire de l'alliage CuBe a 2 pour cent de Be, constituant les dynodes suivant le traitement des surfaces, et l'influence de la tension sur le gain par etage sont discutees. Des resultats d'essais concernant: l'influence de la masse des ions sur le gain, le bruit de fond de l'appareil et la repartition en energie des impulsions de sortie sur un multiplicateur a gain eleve (q.q. 10{sup 7}) sont donnes. Enfin, sont rapportees les performances du multiplicateur. 1- pour un gain faible

  1. Study of the muon production from open heavy flavours predicted by the Color Glass Condensate model in proton-proton and proton-lead collision with the Alice muon spectrometer at LHC; Etude de la production de muons issus des saveurs lourdes predite par le modele de Color Glass Condensate dans les collisions proton-proton et proton-plomb dans l'acceptance du spectrometre a muons de l'experience Alice du LHC

    Energy Technology Data Exchange (ETDEWEB)

    Charpy, A

    2007-10-15

    The whole particle physics community is waiting for the Large Hadron Collider (LHC) commissioning at CERN. Indeed, the potential of discovery is very large in lots of themes. In particular, it will be possible to test the developments of the Quantum Chromodynamics (QCD) achieved during last years. One of these, the Colour Glass Condensate, describes the parton distributions of the nucleus in the saturation region, i.e. at small x. This theoretical description of the initial conditions of the heavy ion collisions is necessary to predict the heavy quark cross section production which evolves in a possible deconfined matter: the Quark-Gluon Plasma (PQG). ALICE is the LHC experiment mainly dedicated to the study of the PQG produced in ultra-relativistic heavy ion collisions. The measurement of J /{psi} and {upsilon} resonance suppression is a signature of this deconfined medium which is studied with the ALICE muon spectrometer. Its acceptance at large rapidity is well adapted for studying the prediction of CGC at small-x. The first part of this report presents the results of beam test experiment at CERN. It was the first time that the muon spectrometer tracking chambers were tested equipped with the final version of the front end electronics and the data acquisition system CROCUS. The relevant calibration parameters of the front end electronics were introduced in the analysis in order to improve the quality of the track reconstruction. In the second part. these parameters were used in the simulations. The last part proposes a study of the CGC with the ALICE muon spectrometer. involving the measurements of open charm and open beauty. (author)

  2. Analysis of solids by spark-source mass spectrometry; Analyse des solides au spectrometre de masse a etincelles

    Energy Technology Data Exchange (ETDEWEB)

    Stefani, R; Desjardins, M; Brun, J C; Cornu, A; Bourguillot, R [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1965-07-01

    Spark source mass spectrometer MS7 has been designed to determine traces of impurities in solids without standards. An atlas of 12 000 lines, assembled in the Grenoble laboratory, allows a quick investigation of mass spectra, notwithstanding their complexity due to multiply charged and polyatomic darkening. Photometric measurements increase accuracy calibration curve is known for each photo-plate. Further, reproducibility is better, if random fluctuations of matrix line darkening are corrected. So far, in a concentration range of 0,01 to 1 000 ppm (atomic), reproducibility is approximately 20 per cent, but absolute value of results depends on 'sensitivity coefficients'. (authors) [French] Le spectrometre de masse a etincelles, de type MS7, est destine a l'analyse chimique de traces dans les solides, sans echantillons etalons. L'emploi de catalogues de 12 000 raies, elabores au laboratoire, permet un depouillement rapide des spectres, malgre leur complexite due aux ionisations multiples et aux associations d'atomes. Le niveau d'apparition d'une impurete donne une estimation de sa teneur, mais la valeur du renseignement depend de la preparation des electrodes et de la connaissance plus ou moins approfondie des processus d'ionisation dans l'etincelle et de noircissement des emulsions photographiques. Les mesures photometriques augmentent la precision des resultats, si l'on determine systematiquement la courbe de noircissement de chaque plaque. De meme la reproductibilite est amelioree si l'on tient compte des fluctuations statistiques du noircissement de l'emulsion par les ions de la matrice. Actuellement, les concentrations mesurees dans le domaine de 0,01 a 1000 ppm atomiques sont reproductibles a 20 pour cent pres, mais leur valeur absolue n'est assuree qu'a un coefficient 3 pres. Des etudes sont en cours pour calibrer l'appareil en valeur absolue, par une determination des coefficients de sensibilite a partir d'echantillons etalons. (auteurs)

  3. OpenChrom: a cross-platform open source software for the mass spectrometric analysis of chromatographic data.

    Science.gov (United States)

    Wenig, Philip; Odermatt, Juergen

    2010-07-30

    Today, data evaluation has become a bottleneck in chromatographic science. Analytical instruments equipped with automated samplers yield large amounts of measurement data, which needs to be verified and analyzed. Since nearly every GC/MS instrument vendor offers its own data format and software tools, the consequences are problems with data exchange and a lack of comparability between the analytical results. To challenge this situation a number of either commercial or non-profit software applications have been developed. These applications provide functionalities to import and analyze several data formats but have shortcomings in terms of the transparency of the implemented analytical algorithms and/or are restricted to a specific computer platform. This work describes a native approach to handle chromatographic data files. The approach can be extended in its functionality such as facilities to detect baselines, to detect, integrate and identify peaks and to compare mass spectra, as well as the ability to internationalize the application. Additionally, filters can be applied on the chromatographic data to enhance its quality, for example to remove background and noise. Extended operations like do, undo and redo are supported. OpenChrom is a software application to edit and analyze mass spectrometric chromatographic data. It is extensible in many different ways, depending on the demands of the users or the analytical procedures and algorithms. It offers a customizable graphical user interface. The software is independent of the operating system, due to the fact that the Rich Client Platform is written in Java. OpenChrom is released under the Eclipse Public License 1.0 (EPL). There are no license constraints regarding extensions. They can be published using open source as well as proprietary licenses. OpenChrom is available free of charge at http://www.openchrom.net.

  4. Mass spectrometric measurement of urinary kynurenine-to-tryptophan ratio in children with and without urinary tract infection.

    Science.gov (United States)

    Yarbrough, Melanie L; Briden, Kelleigh E; Mitsios, John V; Weindel, Annette L; Terrill, Cindy M; Hunstad, David A; Dietzen, Dennis J

    2018-04-19

    Indoleamine-2,3-dioxygenase (IDO) catalyzes the first step of tryptophan (Trp) catabolism, yielding kynurenine (Kyn) metabolites. The kynurenine-to-tryptophan (K/T) ratio is used as a surrogate for biological IDO enzyme activity. IDO expression is increased during Escherichia coli urinary tract infection (UTI). Thus, our objective was to develop a method for measurement of Kyn/Trp ratio in human blood and urine and evaluate its use as a biomarker of UTI. A mass spectrometric method was developed to measure Trp and Kyn in serum and urine specimens. The method was applied to clinical urine specimens from symptomatic pediatric patients with laboratory-confirmed UTI or other acute conditions and from healthy controls. The liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was linear to 500 μmol/L for both Trp and Kyn. Imprecision ranged from 5 to 15% for Trp and 6-20% for Kyn. Analytical recoveries of Trp and Kyn ranged from 96 to 119% in serum and 90-97% in urine. No correlation was found between the K/T ratio and circulating IDO mass (r = 0.110) in serum. Urinary Kyn and Trp in the pediatric test cohort demonstrated elevations in the K/T ratio in symptomatic patients with UTI (median 13.08) and without UTI (median 14.38) compared to healthy controls (median 4.93; p < 0.001 for both comparisons). No significant difference in K/T ratio was noted between symptomatic patients with and without UTI (p = 0.84). Measurement of Trp and Kyn by LC-MS/MS is accurate and precise in serum and urine specimens. While urinary K/T ratio is not a specific biomarker for UTI, it may represent a general indicator of a systemic inflammatory process. Copyright © 2018 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  5. Elimination of ionic interference effects in the atomic absorption spectrometric determination of ruthenium

    International Nuclear Information System (INIS)

    El-Defrawy, M.M.M.; Posta, J.; Beck, M.T.

    1978-01-01

    In connection with work on the catalytic effect of ruthenium complexes, new compounds were prepared. Atomic absorption spectrometry (a.a.s.) was to be used for their analysis. The standard methods could not be applied to the complexes studied, therefore the effect of cyanide ions for elimination of interfering effects has been studied, because of the great stability of cyanide complexes. (Auth.)

  6. Probing the Conformation of an IgG1 Monoclonal Antibody in Lyophilized Solids Using Solid-State Hydrogen-Deuterium Exchange with Mass Spectrometric Analysis (ssHDX-MS).

    Science.gov (United States)

    Moussa, Ehab M; Singh, Satish K; Kimmel, Michael; Nema, Sandeep; Topp, Elizabeth M

    2018-02-05

    Therapeutic proteins are often formulated as lyophilized products to improve their stability and prolong shelf life. The stability of proteins in the solid-state has been correlated with preservation of native higher order structure and/or molecular mobility in the solid matrix, with varying success. In the studies reported here, we used solid-state hydrogen-deuterium exchange with mass spectrometric analysis (ssHDX-MS) to study the conformation of an IgG1 monoclonal antibody (mAb) in lyophilized solids and related the extent of ssHDX to aggregation during storage in the solid phase. The results demonstrate that the extent of ssHDX correlated better with aggregation rate during storage than did solid-state Fourier-transform infrared (ssFTIR) spectroscopic measurements. Interestingly, adding histidine to sucrose at different formulation pH conditions decreased aggregation of the mAb, an effect that did not correlate with structural or conformational changes as measured by ssFTIR or ssHDX-MS. Moreover, peptide-level ssHDX-MS analysis in four selected formulations demonstrated global changes across the structure of the mAb when lyophilized with sucrose, trehalose, or mannitol, whereas site-specific changes were observed when lyophilized with histidine as the sole excipient.

  7. Determination of Non-Transferrin Bound Iron, Transferrin Bound Iron, Drug Bound Iron and Total Iron in Serum in a Rats after IV Administration of Sodium Ferric Gluconate Complex by Simple Ultrafiltration Inductively Coupled Plasma Mass Spectrometric Detection

    Directory of Open Access Journals (Sweden)

    Murali K. Matta

    2018-02-01

    Full Text Available A rapid, sensitive and specific ultrafiltration inductively-coupled plasma mass spectrometry method was developed and validated for the quantification of non-transferrin bound iron (NTBI, transferrin bound iron (TBI, drug bound iron (DI and total iron (TI in the same rat serum sample after intravenous (IV administration of iron gluconate nanoparticles in sucrose solution (Ferrlecit®. Ultrafiltration with a 30 kDa molecular cut-off filter was used for sample cleanup. Different elution solvents were used to separate each form of iron from sample serum. Isolated fractions were subjected to inductively-coupled mass spectrometric analysis after microwave digestion in 4% nitric acid. The reproducibility of the method was evaluated by precision and accuracy. The calibration curve demonstrated linearity from 5–500 ng/mL with a regression (r2 of more than 0.998. This method was effectively implemented to quantify rat pharmacokinetic study samples after intravenous administration of Ferrlecit®. The method was successfully applied to a pharmacokinetic (PK study of Ferrlecit in rats. The colloidal iron followed first order kinetics with half-life of 2.2 h and reached background or pre-dose levels after 12 h post-dosing. The drug shown a clearance of 0.31 mL/min/kg and volume of distribution of 0.05 L/kg. 19.4 ± 2.4 mL/h/kg.

  8. Mass spectrometric analysis of small negative ions (e/m < 100) produced by Trichel pulse negative corona discharge fed by ozonised air

    OpenAIRE

    Skalny, J.D.; Horvath, G.; Mason, N.

    2007-01-01

    Mass spectrometric analysis of small negative ions (e/m < 100) produced by DC negative corona discharge in ozonised wet air both in flow and flow-stopped regimes was conducted at pressure of 30 kPa. The point-to-plain electrode system has been used. The yield of individual ions is strongly affected by trace concentrations of ozone in both regimes. Ozone concentration greater than 25 ppm is sufficient to completely suppress the appearance of O2- and a NO2- ion as well as theirs clusters in the...

  9. iMS2Flux – a high–throughput processing tool for stable isotope labeled mass spectrometric data used for metabolic flux analysis

    Directory of Open Access Journals (Sweden)

    Poskar C Hart

    2012-11-01

    Full Text Available Abstract Background Metabolic flux analysis has become an established method in systems biology and functional genomics. The most common approach for determining intracellular metabolic fluxes is to utilize mass spectrometry in combination with stable isotope labeling experiments. However, before the mass spectrometric data can be used it has to be corrected for biases caused by naturally occurring stable isotopes, by the analytical technique(s employed, or by the biological sample itself. Finally the MS data and the labeling information it contains have to be assembled into a data format usable by flux analysis software (of which several dedicated packages exist. Currently the processing of mass spectrometric data is time-consuming and error-prone requiring peak by peak cut-and-paste analysis and manual curation. In order to facilitate high-throughput metabolic flux analysis, the automation of multiple steps in the analytical workflow is necessary. Results Here we describe iMS2Flux, software developed to automate, standardize and connect the data flow between mass spectrometric measurements and flux analysis programs. This tool streamlines the transfer of data from extraction via correction tools to 13C-Flux software by processing MS data from stable isotope labeling experiments. It allows the correction of large and heterogeneous MS datasets for the presence of naturally occurring stable isotopes, initial biomass and several mass spectrometry effects. Before and after data correction, several checks can be performed to ensure accurate data. The corrected data may be returned in a variety of formats including those used by metabolic flux analysis software such as 13CFLUX, OpenFLUX and 13CFLUX2. Conclusion iMS2Flux is a versatile, easy to use tool for the automated processing of mass spectrometric data containing isotope labeling information. It represents the core framework for a standardized workflow and data processing. Due to its flexibility

  10. APPLICATION OF THE SPECTROMETRIC METHOD FOR CALCULATING THE DOSE RATE FOR CREATING CALIBRATION HIGHLY SENSITIVE INSTRUMENTS BASED ON SCINTILLATION DETECTION UNITS

    Directory of Open Access Journals (Sweden)

    R. V. Lukashevich

    2017-01-01

    Full Text Available Devices based on scintillation detector are highly sensitive to photon radiation and are widely used to measure the environment dose rate. Modernization of the measuring path to minimize the error in measuring the response of the detector to gamma radiation has already reached its technological ceiling and does not give the proper effect. More promising for this purpose are new methods of processing the obtained spectrometric information. The purpose of this work is the development of highly sensitive instruments based on scintillation detection units using a spectrometric method for calculating dose rate.In this paper we consider the spectrometric method of dosimetry of gamma radiation based on the transformation of the measured instrumental spectrum. Using predetermined or measured functions of the detector response to the action of gamma radiation of a given energy and flux density, a certain function of the energy G(E is determined. Using this function as the core of the integral transformation from the field to dose characteristic, it is possible to obtain the dose value directly from the current instrumentation spectrum. Applying the function G(E to the energy distribution of the fluence of photon radiation in the environment, the total dose rate can be determined without information on the distribution of radioisotopes in the environment.To determine G(E by Monte-Carlo method instrumental response function of the scintillator detector to monoenergetic photon radiation sources as well as other characteristics are calculated. Then the whole full-scale energy range is divided into energy ranges for which the function G(E is calculated using a linear interpolation.Spectrometric method for dose calculation using the function G(E, which allows the use of scintillation detection units for a wide range of dosimetry applications is considered in the article. As well as describes the method of calculating this function by using Monte-Carlo methods

  11. Quantitative analysis of flavonols, flavones, and flavanones in fruits, vegetables and beverages by high-performance liquid chromatography with photo-diode array and mass spectrometric detection

    DEFF Research Database (Denmark)

    Justesen, U.; Knuthsen, Pia; Leth, Torben

    1998-01-01

    after acid hydrolysis of freeze-dried food material. Identification was based on retention time, UV and mass spectra by comparison with commercial standards, and the UV peak areas were used for quantitation of the flavonoid contents. Examples of HPLC-MS analyses of orange pulp, tomato, and apple......A high-performance liquid chromatographic (HPLC) separation method viith photo-diode array (PDA) and mass spectrometric (MS) detection was developed to determine and quantify flavonols, flavones, and flavanones in fruits, vegetables and beverages. The compounds were analysed as aglycones, obtained...

  12. Autoresonant-spectrometric determination of the residual gas composition in the ALPHA experiment apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Amole, C.; Capra, A.; Menary, S. [Department of Physics and Astronomy, York University, Toronto, Ontario M3J 1P3 (Canada); Ashkezari, M. D.; Hayden, M. E. [Department of Physics, Simon Fraser University, Burnaby, British Columbia V5A 1S6 (Canada); Baquero-Ruiz, M.; Chapman, S.; Little, A.; Povilus, A.; So, C.; Turner, M. [Department of Physics, University of California, Berkeley, California 94720-7300 (United States); Bertsche, W. [Department of Physics, Swansea University, Swansea SA2 8PP (United Kingdom); School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, United Kingdom and The Cockcroft Institute, Daresbury Laboratory, Warrington WA4 4AD (United Kingdom); Butler, E. [Physics Department, CERN, CH-1211 Geneva 23 (Switzerland); Cesar, C. L.; Silveira, D. M. [Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-972 (Brazil); Charlton, M.; Eriksson, S.; Isaac, C. A.; Madsen, N.; Napoli, S. C. [Department of Physics, Swansea University, Swansea SA2 8PP (United Kingdom); Collaboration: ALPHA Collaboration; and others

    2013-06-15

    Knowledge of the residual gas composition in the ALPHA experiment apparatus is important in our studies of antihydrogen and nonneutral plasmas. A technique based on autoresonant ion extraction from an electrostatic potential well has been developed that enables the study of the vacuum in our trap. Computer simulations allow an interpretation of our measurements and provide the residual gas composition under operating conditions typical of those used in experiments to produce, trap, and study antihydrogen. The methods developed may also be applicable in a range of atomic and molecular trap experiments where Penning-Malmberg traps are used and where access is limited.

  13. Solid phase extraction-electrospray ionization mass spectrometric method for the determination of palladium

    International Nuclear Information System (INIS)

    Pranaw Kumar; Telmore, Vijay M.; Jaison, P.G.; Sarkar, Arnab; Alamelu, D.; Aggarwal, S.K.

    2015-01-01

    Platinum group of element (PGEs) are extensively used as a catalyst and anticancer reagent. Due to the soft nature of PGEs, sulphur based donar ligands are used for the separation of these elements. Studies on the formation of different species are helpful for obtaining the ideas about separation of these elements from the complex matrices. Palladium (Pd) is studied as a representative element which is also formed by nuclear fission of fissile nuclides. In view of the relatively small amount of solvent required for separation, solid phase extraction is preferred over most of the separation methods. Solid phase extraction method using DPX as a stationary phase was previously reported for the separation of Pd in SHLLW using benzoylthiourea as a ligand. However, in case of large volume samples manual extraction by DPX is tedious task. In the present studies, the feasibility of extraction using benzoylthiourea on automated solid phase extraction system was carried out for the extraction of Pd

  14. Mass spectrometric probes of metal cluster distributions and metastable ion decay

    International Nuclear Information System (INIS)

    Parks, E.K.; Liu, K.; Cole, S.K.; Riley, S.J.

    1988-01-01

    The study of metal clusters has provided both an opportunity and a challenge to the application of mass spectrometry. These days the most often-used technique for cluster generation - laser vaporization - leads to extensive distributions of cluster sizes, from one to perhaps thousands of atoms, and most studies reported to date use excimer laser ionization and time-of-flight mass spectrometry for cluster detection. Our apparatus is a simple one-stage TOF design employing Wiley-McLauren spatial focusing and a one-meter drift tube. In a second apparatus employing a pulsed valve in the cluster source, we see asymmetric broadening of niobium cluster mass peaks under multiphoton ionization conditions, indicating metastable decay of parent cluster ions. Other studies of niobium clusters have shown no such asymmetric peaks. 2 figs

  15. Chromatographic, Spectrometric and NMR Characterization of a New Set of Glucuronic Acid Esters Synthesized by Lipase

    Directory of Open Access Journals (Sweden)

    Michel Marlier

    2007-01-01

    Full Text Available An enzymatic synthesis was developed on a new set of D-glucuronic acid esters and particularly the tetradecyl-D-glucopyranosiduronate also named tetradecyl D-glucuronate. Chromatographic analyses revealed the presence of the ester as a mixture of anomeric forms for carbon chain lengths superior to 12. TOF/MS and MS/MS studies confirmed the synthesis of glucuronic acid ester. The NMR study also confirmed the structure of glucuronic acid esters and clearly revealed an anomeric (α/β ratio equivalent to 3/2

  16. Application of mass spectrometric techniques to delineate the modes-of-action of anticancer metallodrugs

    NARCIS (Netherlands)

    Hartinger, Christian G.; Groessl, Michael; Meier, Samuel M.; Casini, Angela; Dyson, Paul J.

    2013-01-01

    Mass spectrometry (MS) has emerged as an important tool for studying anticancer metallodrugs in complex biological samples and for characterising their interactions with biomolecules and potential targets on a molecular level. The exact modes-of-action of these coordination compounds and especially

  17. Identification of organic iodocompounds in the PUREX process with the help of methods for chromatographic separation and spectrometric detection as well as characterization of their behavior during extraction. Final report

    International Nuclear Information System (INIS)

    Gaul, G.; Gibau, F.; Knoechel, A.

    1993-01-01

    In the system HNO 3 KI, Dodecan and TBP the radiolytic reactive behaviour of the described compounds during the dissolution of nuclear fuel elements was simulated. External γ-irradiation gave the best informations. As a consequence of radiolyticly induced reactions several volatile and non-volatile iodoorganic compounds like iodoalkanes, iodonitroalkanes and iodonitroalkylphosphates are formed. They were separated by gaschromatography (GC) and high performance liquid chromatography (HPLC). For HPLC a special photolytic/electrochemical detector with comparable sensitivity like the electroncapture detector in the GC-field was developed. With the help of the two described chromatographic techniques the different iodoorganic compounds could be separated singularily or in groups of isomers. The separation of all compounds demands two-dimensional chromatographies including the capillary-SFC, which was not available for this project. Most of the iodoorganic compounds could be identified by comparison of the retention times of well known compounds. In the other cases, the compounds were studied mass-spectrometrically. Unfortunately all available ionisation techniques (EI; CI; FAB) were too hard for the labile C-I-bond. Therefore an identification of these compounds was not possible. In any case, instructive fingerprint spectra are available enabling relationships between the generation of the iodoorganic compounds and the reaction conditions during their formation. (orig.) [de

  18. Extraction and preconcentration of trace Al and Cr from vegetable samples by vortex-assisted ionic liquid-based dispersive liquid-liquid microextraction prior to atomic absorption spectrometric determination.

    Science.gov (United States)

    Altunay, Nail; Yıldırım, Emre; Gürkan, Ramazan

    2018-04-15

    In the study, a simple, and efficient microextraction approach, which is termed as vortex-assisted ionic liquid-based dispersive liquid-liquid microextraction (VA-IL-DLLME), was developed for flame atomic absorption spectrometric analysis of aluminum (Al) and chromium (Cr) in vegetables. The method is based on the formation of anionic chelate complexes of Al(III) and Cr(VI) with o-hydroxy azo dye, at pH 6.5, and then extraction of the hydrophobic ternary complexes formed in presence of cetyltrimethylammonium bromide (CTAB) into a 125 μL volume of 1-butyl-3-methylimidazolium bis(trifluorosulfonyl)imide [C 4 mim][Tf 2 N]) as extraction solvent. Under optimum conditions, the detection limits were 0.02 µg L -1 in linear working range of 0.07-100 µg L -1 for Al(III), and 0.05 µg L -1 in linear working range of 0.2-80 µg L -1 for Cr(VI). After the validation by analysis of a certified reference material (CRM), the method was successfully applied to the determination of Al and Cr in vegetables using standard addition method. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. A Parallel Reaction Monitoring Mass Spectrometric Method for Analysis of Potential CSF Biomarkers for Alzheimer's Disease

    DEFF Research Database (Denmark)

    Brinkmalm, Gunnar; Sjödin, Simon; Simonsen, Anja Hviid

    2018-01-01

    SCOPE: The aim of this study was to develop and evaluate a parallel reaction monitoring mass spectrometry (PRM-MS) assay consisting of a panel of potential protein biomarkers in cerebrospinal fluid (CSF). EXPERIMENTAL DESIGN: Thirteen proteins were selected based on their association with neurode......SCOPE: The aim of this study was to develop and evaluate a parallel reaction monitoring mass spectrometry (PRM-MS) assay consisting of a panel of potential protein biomarkers in cerebrospinal fluid (CSF). EXPERIMENTAL DESIGN: Thirteen proteins were selected based on their association...... with neurodegenerative diseases and involvement in synaptic function, secretory vesicle function, or innate immune system. CSF samples were digested and two to three peptides per protein were quantified using stable isotope-labeled peptide standards. RESULTS: Coefficients of variation were generally below 15%. Clinical...

  20. Effect of the wavelength on laser induced breakdown spectrometric analysis of archaeological bone

    Energy Technology Data Exchange (ETDEWEB)

    Kasem, M.A. [National Institute of Laser Enhanced Science (NILES), Cairo University, Giza (Egypt); Gonzalez, J.J.; Russo, R.E. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Harith, M.A., E-mail: mharithm@niles.edu.eg [National Institute of Laser Enhanced Science (NILES), Cairo University, Giza (Egypt)

    2014-11-01

    The analytical exploitation of the laser induced plasma suffers from its transient behavior due to some nonlinear effects. These phenomena are matrix-dependent and limit the use of LIBS to mostly semi-quantitative precision. The plasma parameters have to be kept as constant as possible during LIBS measurements. Studying archaeological bone samples using LIBS technique could be more difficult since these samples are less tough in their texture than many other solid samples. Thus, the ablation process could change the sample morphological features rapidly resulting in poor reproducibility and statistics. Furthermore archaeological bones are subjected to diagenesis effects due to burial environment and postmortem effects. In the present work comparative analytical study of UV (266 nm) and IR (1064 nm) LIBS for archaeological bone samples belonging to four ancient Egyptian dynasties representing the middle kingdom (1980–1630 BC), 2nd intermediate period (1630–1539/23 BC), Roman–Greek period (30 BC–A.D. 395) and the late period (664–332 BC). Measurements have been performed under identical experimental conditions except the laser wavelength to examine its effects. Elemental fluctuations within the same dynasty were studied for reliable information about each dynasty. The analytical results demonstrated that UV-LIBS gives a more realistic picture for bone elemental composition within the same dynasty, and bone ash could be more suitable as a reference material for bone calibration in the case of UV-LIBS. - Highlights: • UV and IR LIBS for archaeological bone samples have been performed. • Elemental fluctuations within the same dynasty were studied. • UV-LIBS gave realistic picture for bone elemental composition for the same dynasty. • Depth profile for Sr/Ca concentration was an indicator for the diagenesis effect. • Bone ash is the most suitable for calcified tissue calibration for UV-LIBS.