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Sample records for ams 14c dating

  1. {sup 14}C AMS dating Yongcheon cave

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J.H., E-mail: jefflee@snu.ac.kr [AMS Lab., NCIRF, Seoul National University, Seoul 151-742 (Korea, Republic of); Choe, K. [AMS Lab., NCIRF, Seoul National University, Seoul 151-742 (Korea, Republic of); Kim, J.C. [Dept. of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of); Choi, S.H.; Kang, J.; Song, S.; Song, Y.M. [AMS Lab., NCIRF, Seoul National University, Seoul 151-742 (Korea, Republic of); Jang, J.G. [Jeju National Museum, Jeju 690-782 (Korea, Republic of)

    2013-01-15

    The biggest island in South Korea is Jeju Island, which lies 80 km south of the mainland and has one shield volcano, Mt. Halla. The volcanic island and its lava tubes were added to the world heritage list by UNESCO in 2007. Among the many lava tubes on the island, a unique cave had been accidentally found in 2005 while some workers were replacing a telephone pole. Until the discovery, it had been completely isolated from the outside by naturally-built sand blocks. Yongcheon cave is a lime-decorated lava tube showing both the properties of a volcanic lava tube and a limestone cave. This cave, about 3 km in length, is acknowledged to be the best of this type in the world and includes a large clean-water lake, lava falls, and richly developed speleothems inside it. Even though there is archaeological evidence from well preserved pottery that ancient people entered this place, the preservation of artifacts was ensured by a geological change that made later entrance difficult. We have collected charcoal samples scattered around the cave and dated them using AMS. Ages were in the range of ca. 1570-1260 BP (A.D. 340-880) and this corresponds to the Ancient Three Kingdoms and the Unified Silla era in Korean history. The {sup 14}C AMS measurement results presented in this paper on wood charcoal provide precise dates which will be very useful not only to clarify the nature of human activities in this cave but also to provide reference dates when comparing other dating methods.

  2. 14C AMS dating Yongcheon cave

    International Nuclear Information System (INIS)

    Lee, J.H.; Choe, K.; Kim, J.C.; Choi, S.H.; Kang, J.; Song, S.; Song, Y.M.; Jang, J.G.

    2013-01-01

    The biggest island in South Korea is Jeju Island, which lies 80 km south of the mainland and has one shield volcano, Mt. Halla. The volcanic island and its lava tubes were added to the world heritage list by UNESCO in 2007. Among the many lava tubes on the island, a unique cave had been accidentally found in 2005 while some workers were replacing a telephone pole. Until the discovery, it had been completely isolated from the outside by naturally-built sand blocks. Yongcheon cave is a lime-decorated lava tube showing both the properties of a volcanic lava tube and a limestone cave. This cave, about 3 km in length, is acknowledged to be the best of this type in the world and includes a large clean-water lake, lava falls, and richly developed speleothems inside it. Even though there is archaeological evidence from well preserved pottery that ancient people entered this place, the preservation of artifacts was ensured by a geological change that made later entrance difficult. We have collected charcoal samples scattered around the cave and dated them using AMS. Ages were in the range of ca. 1570-1260 BP (A.D. 340–880) and this corresponds to the Ancient Three Kingdoms and the Unified Silla era in Korean history. The 14 C AMS measurement results presented in this paper on wood charcoal provide precise dates which will be very useful not only to clarify the nature of human activities in this cave but also to provide reference dates when comparing other dating methods.

  3. Laser AMS 14C dating of rock surface accretions

    International Nuclear Information System (INIS)

    Watchman, A.; Campbell, F.

    1997-01-01

    Full text: Equipment has been purchased using a large Earth Sciences and Engineering ARC grant and installed in the Department of Anthropology and Archaeology, James Cook University. A krypton-ion laser used initially at Laval University, Quebec to demonstrate the potential of focusing light energy to induce oxidation of carbon-bearing substances has been replaced by a carbon dioxide laser. This decision was based on reducing the startup cost at James Cook University, increasing options for a wide range of output power, considerations for future applications and the cost of gas refills. A disadvantage of using the carbon dioxide laser is that non-visible light optics are needed because of the infrared output wavelength from the carbon dioxide. This has required the replacement of the glass window of the vacuum-tight micro-combustion chamber with a sodium chloride window and placing the equipment in a dehumidifier room. Laser light power experiments have so far been conducted on optimising the output from the laser and minimising the focal waist of the beam by adjusting the focusing mirrors and lenses. The aim of developing a focused laser system is to enable the dating of carbon in finely laminated rock surface accretions, but before this can be achieved a series of tests is planned to ensure that the focused laser system totally converts all the carbon-bearing substances under the beam into carbon dioxide. This is essential in order that the isotopic values representative of the carbon in the accretions is converted into carbon dioxide. Known quantities of graphite, charcoal, wood cellulose and calcium oxalate salts are being subjected to focused laser combustion or decomposition and the volumes of gas produced at different light powers are being measured. Isotopic measurements are also being conducted on the resulting gases to ensure that fractionation of carbon isotopes is not a problem. The paper will describe the arrangement of equipment and explain the

  4. A new graphite preparation line for AMS 14C dating in the Zagreb Radiocarbon Laboratory

    Science.gov (United States)

    Krajcar Bronić, I.; Horvatinčić, N.; Sironić, A.; Obelić, B.; Barešić, J.; Felja, I.

    2010-04-01

    The new line for preparation of graphite samples for 14C dating by AMS has been constructed in the Zagreb Radiocarbon Laboratory. The performance of the rig and sample preparation procedure has been validated by preparing graphites from various reference materials of known 14C activity. The yield of the graphitization was good and the measured fraction of modern carbon ( Fm) values have not significantly deviated from the expected ones. Detailed analysis of measured Fm values indicates a slight bias to more positive values and should be carefully investigated.

  5. High resolution 14C dating of surface peat using the AMS technique

    International Nuclear Information System (INIS)

    Tolonen, K.; Possnert, G.; Jungner, H.; Sonninen, E.; Alm, J.

    1992-01-01

    In an AMS (Accelerator Mass Spectrometric) determination of 14 C from moss-increment dated samples from a Sphagnum fuscum hummock, a clear peak representing the time of high 14 C activity in the atmosphere due to nuclear bomb tests was found. The C-14 activities in the peat profile at deeper levels, corresponding to the period down to 1600 Bp, showed similar variations as the atmospheric values. The time scale obtained from radiocarbon dating fitted well with results from moss-increment counting, pollen analysis and dendrochronological dating of a fire horizon. Using the bomb layers and refixing into growing peat was estimated. The fraction of soil carbon dioxide taken up by the contemporary Sphagnum Sward was thus found to be in the order of 20 %. (orig.). (15 refs., 5 figs., 2 tabs.)

  6. Soil particles reworking evidences by AMS 14C dating of charcoal

    International Nuclear Information System (INIS)

    Carcaillet, C.

    2001-01-01

    Soil charcoal dating is a time proxy for soil pedogenesis. I test the stratification hypothesis by AMS 14 C dating of charcoal fragments from soil profiles between 1700 and 1900 m with respect to altitude within the Alps. The charcoal fragments are around 1 mm in size. There is no age/depth relationship for charcoal particles of the size millimeter. The results are discussed in light of the role of soil fauna, up-rooting and colluvial processes. Although biotic pedoturbation is poorly described in mountain and sub-alpine elevation, I hypothesize that this process is very active and plays a major role on the soil functioning. (author)

  7. Correlating the Ancient Maya and Modern European Calendars with High-Precision AMS 14C Dating

    Science.gov (United States)

    Kennett, Douglas J.; Hajdas, Irka; Culleton, Brendan J.; Belmecheri, Soumaya; Martin, Simon; Neff, Hector; Awe, Jaime; Graham, Heather V.; Freeman, Katherine H.; Newsom, Lee; Lentz, David L.; Anselmetti, Flavio S.; Robinson, Mark; Marwan, Norbert; Southon, John; Hodell, David A.; Haug, Gerald H.

    2013-04-01

    The reasons for the development and collapse of Maya civilization remain controversial and historical events carved on stone monuments throughout this region provide a remarkable source of data about the rise and fall of these complex polities. Use of these records depends on correlating the Maya and European calendars so that they can be compared with climate and environmental datasets. Correlation constants can vary up to 1000 years and remain controversial. We report a series of high-resolution AMS 14C dates on a wooden lintel collected from the Classic Period city of Tikal bearing Maya calendar dates. The radiocarbon dates were calibrated using a Bayesian statistical model and indicate that the dates were carved on the lintel between AD 658-696. This strongly supports the Goodman-Martínez-Thompson (GMT) correlation and the hypothesis that climate change played an important role in the development and demise of this complex civilization.

  8. AMS {sup 14}C dating at CIRCE: The Major Temple in Cumae (NA – Italy)

    Energy Technology Data Exchange (ETDEWEB)

    Capano, M., E-mail: capano@cerege.fr [Seconda Università degli Studi di Napoli – CIRCE (Centre for Isotopic Research on Cultural and Environmental Heritage), San Nicola la Strada, CE (Italy); Rescigno, C.; Sirleto, R. [Dipartimento di Lettere e Beni Culturali, Seconda Università degli Studi di Napoli, Santa Maria Capua Vetere, CE (Italy); Passariello, I. [INNOVA-CIRCE, San Nicola la Strada, CE (Italy); Marzaioli, F.; D’Onofrio, A.; Terrasi, F. [INNOVA-CIRCE, San Nicola la Strada, CE (Italy); Dipartimento di Matematica e Fisica, Seconda Università degli Studi di Napoli, Caserta (Italy)

    2015-10-15

    We present here one recent CIRCE (Centre for Isotopic Research on Cultural and Environmental Heritage) – Caserta (Italy) project on cultural heritage field, analysing several mice bones, discovered in the Major Temple on the acropolis of Cumae (Napoli, Southern Italy). The bones were found in a vase linked to the holy context. In order to know their dating and formulate an hypothesis on their presence on the site, if it was an accidental rodent inclusion (believed on the base of archaeological context to have occurred during building abandonment periods (IV–V or XIII centuries AD)) or an intentional and ritual remain, the bones were {sup 14}C dated by AMS at CIRCE. The results indicate that the mice bones date to the IV century BC and are contemporaneous with building construction. This dating seems to exclude an accidental rodent presence and it supports the hypothesis of Apollo veneration in the temple, based on the already known link between mice and Apollo worship rituals.

  9. Chronologies in wood and resin: AMS 14C dating of pre-Hispanic Caribbean Wood Sculpture

    Science.gov (United States)

    Joanna Ostapkowicz; Christopher Bronk-Ramsey; Fiona Brock; Tom Higham; Alex C. Wiedenhoeft; Erika Ribechini; Jeannette J. Lucejko; Samuel. Wilson

    2012-01-01

    This paper establishes a chronological framework for selected pieces of Caribbean (Tafno/Lucayan) wooden sculpture, enabling previously ahistoric artefacts to fit back into the wider corpus of pre-colonial material culture. Seventy-two 14C AMS determinations from 56 artefacts held in museum collections are reported, including 32 ceremonial

  10. Development of a nanofiltration method for bone collagen {sup 14}C AMS dating

    Energy Technology Data Exchange (ETDEWEB)

    Boudin, Mathieu, E-mail: mathieu.boudin@ugent.be [Royal Institute for Cultural Heritage, Jubelpark 1, B-1000 Brussels (Belgium); Ghent University, Faculty of Bioscience Engineering, Laboratory of Applied Physical Chemistry, Coupure Links 653, B-9000 Ghent (Belgium); Boeckx, Pascal [Ghent University, Faculty of Bioscience Engineering, Laboratory of Applied Physical Chemistry, Coupure Links 653, B-9000 Ghent (Belgium); Buekenhoudt, Anita [Flemish Institute for Technological Research, Separation and Conversion Technology, Boeretang 200, B-2400 Mol (Belgium); Vandenabeele, Peter [Ghent University, Department of Archaeology, Sint-Pietersnieuwstraat 35, B-9000 Ghent (Belgium); Van Strydonck, Mark [Royal Institute for Cultural Heritage, Jubelpark 1, B-1000 Brussels (Belgium)

    2013-01-15

    Radiocarbon dating of bones is usually performed on the collagen fraction. However, this collagen can contain exogenous molecules, including humic substances (HSs) and/or other soil components that may have a different age than the bone. Incomplete removal can result in biased {sup 14}C dates. Ultrafiltration of collagen, dissolved as gelatin (molecular weight (MW) {approx}100,000 Dalton), has received considerable attention to obtain more reliable dates. Ultrafiltration is an effective method of removal of low-molecular weight contaminants from bone collagen but it does not remove high-molecular weight contaminants, such as cross-linked humic collagen complexes. However, comparative dating studies have raised the question whether this cleaning step itself may introduce contamination with carbon from the filters used. In this study, a nanofiltration method was developed using a ceramic filter to avoid a possible extraneous carbon contamination introduced by the filter. This method should be applicable to various protein materials e.g. collagen, silk, wool, leather and should be able to remove low-molecular and high molecular weight HSs. In this study bone collagen was hot acid hydrolyzed to amino acids and nanofiltrated. A filter with a molecular weight cutoff (MWCO) of 450 Dalton was chosen in order to collect the amino acids in the permeate and the HSs in the retentate. Two pilot studies were set up. Two nanofiltration types were tested in pilot study 1: dead end and cross flow filtration. Humic substance (HS)-solutions with fossil carbon and modern hydrolyzed collagen contaminated with HSs were filtrated and analyzed with spectrofluorescence to determine the HS removal. Cross flow nanofiltration showed the most efficient HS removal. A second pilot study based upon these results was set up wherein only cross flow filtration was performed. {sup 14}C measurements of the permeates of hydrolyzed modern collagen contaminated with fossil HSs demonstrate a significant

  11. 14C-AMS at the Leibniz-Labor: radiometric dating and isotope research

    International Nuclear Information System (INIS)

    Grootes, Pieter M.; Nadeau, Marie-Josee; Rieck, Anke

    2004-01-01

    The Leibniz-Labor was founded to provide radiometric dating services using AMS and measured over 15 000 samples and 26 800 targets up to September 2002. Research and development have primarily been directed at improving the efficiency and reliability of AMS measurements, optimising existing sample preparation procedures for AMS and developing new ones. The standard chemical pre-treatment of organic radiocarbon samples produces often two fractions: one from which contaminants have been removed, and one in which they have been enriched. Dating both fractions reveals the degree of sample contamination. This provides a useful indication of the reliability of the sample age obtained and of the environmental conditions where the sample was taken. Upgrades to reduce maintenance include replacing four cryo- by turbo pumps, installing a deionizer loop, which keeps conductivity between 100 and 150 μS/cm to control corrosion, in the closed cooling water circuit, and developing a new sample wheel, which holds target holders with a groove and spring clip. Long term stability is demonstrated by the results obtained for IAEA reference materials, measured routinely and regularly over the years. Tests made as part of the FIRI project demonstrate that reliable measurements down to <0.1 mg C can be made

  12. 14C AMS dating of fires in the central Amazon rain forest

    International Nuclear Information System (INIS)

    Santos, G.M.; Gomes, P.R.S.; Anjos, R.M.; Cordeiro, R.C.; Turcq, B.J.; Sifeddine, A.; Di Tada, M.L.; Cresswell, R.G.; Fifield, L.K.

    2000-01-01

    Soil samples were collected in tierra firme upland and lowland areas of the Km 41 reserve near Manaus (20 deg. 30'S and 60 deg. W), in Central Brazilian Amazon, within a 1700 m transect, at eight different depth ranges, from surface to 100 cm. The highest charcoal concentrations were found at the depth range of 20-50 cm. AMS radiocarbon dating of 31 samples were performed at the ANU. The ages of the charcoals were found to vary within the 130 to 2400 years BP range, mostly between 1200 and 1400 years BP, one of the known Holocene dry periods of the Amazon region. The results show that the fires have regional dimensions and are associated with climate regional changes

  13. The contribution of 14C AMS dating to the Greater Angkor archaeological project

    International Nuclear Information System (INIS)

    Zoppi, U.; Barbetti, M.; Fletcher, R.; Hua, Q.; Chhem, R.K.; Pottier, C.; Watanasak, M.

    2004-01-01

    For well over five centuries, the Khmer kingdom ruled over a vast territory, including most of what is now known as Cambodia, Thailand, Vietnam and Laos. Between the 9th and 14th century AD, the Khmer Kings developed the Angkor area into a remarkable administrative and religious centre for their society. According to new estimates by the Greater Angkor Project, the entire urban complex of the capital city covered about 1000 square km making it probably the largest archaeological site in the world. Great stone temples and some other monumental structures and earthworks are the only visible remains of this fascinating civilisation. Thankfully, there is a substantial on-going multinational effort to preserve and restore what is left and in 1992 UNESCO (United Nations Educational Scientific and Cultural Organisation) declared Angkor a World Heritage Site. This paper presents two particular aspects of the Greater Angkor Project where radiocarbon dating by AMS specifically added to our knowledge of the history of this ancient capital city

  14. The AMS {sup 14}C dating of Iron Age rice chaff ceramic temper from Ban Non Wat, Thailand: First results and its interpretation

    Energy Technology Data Exchange (ETDEWEB)

    Higham, Charles F.W., E-mail: charles.higham@otago.ac.n [Department of Anthropology, Otago University, Dunedin (New Zealand); Kuzmin, Yaroslav V. [Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, Koptuyg Ave. 3, Novosibirsk 630090 (Russian Federation); Burr, G.S. [Arizona AMS Laboratory, University of Arizona, Tucson, AZ 85721 0081 (United States)

    2010-04-15

    Pottery tempered with rice chaff from the early Iron Age cemetery of Ban Non Wat site, northeast Thailand, has been subjected to direct AMS {sup 14}C dating, using low temperature combustion with oxygen as originally developed by authors. The carbon yield (0.2-0.5%) testifies the suitability of this pottery for dating. However, not all the results are in agreement with expected archaeological ages and other {sup 14}C dates from the studied site and neighboring site of Noen U-Loke. This calls for a thorough analysis and interpretation of pottery temper dates from the region.

  15. 14C AMS dates on Rattus exulans bones from natural and archaeological contexts on Norfolk Island, south-west Pacific

    International Nuclear Information System (INIS)

    Holdaway, R.N.; Anderson, A.J.

    1998-01-01

    The Pacific rat (Rattus exulans) was transported throughout the western Pacific by migrant peoples in prehistory. Meredith et al (1985) reported a minimum date for the presence of Rattus exulans on Norfolk Island using dates on charcoal from an apparently enclosing layer (the upper part of their Unit C4) in Cemetery Bay. 8 refs., 3 tabs

  16. 14 C dating by using mass spectrometry with particle accelerator

    International Nuclear Information System (INIS)

    Santos, G.M.; Gomes, P.R.S.; Yokoyama, Y.; Tada, M.L. di; Cresswell, R.G.; Fifield, L.K.

    1999-01-01

    The different aspects concerning the 14 C dating are described, including the cosmogenic origin of 14 C, its production and absorption by matter, the procedures to be followed for the age determination and the associated errors, particularly by the Accelerator Mass Spectrometry (AMS) technique, and the different steps of the sample preparation process. (author)

  17. AMS 14 C dating controlled records of monsoon and Indonesian throughflow variability from the eastern Indian Ocean of the past 32,000 years

    Science.gov (United States)

    Li, Z. Y.; Chen, M. T.; Shi, X.; Liu, S.; Wang, H.

    2015-12-01

    Zi-Ye Li a, Min-Te Chen b, Hou-Jie Wang a, Sheng-Fa Liu c, Xue-Fa Shi ca College of Marine Geosciences, Ocean University of China, Qingdao 266100, P.R. Chinab Institute of Applied Geosciences, National Taiwan Ocean University, Keelung, Taiwan 20224, ROCc First Institute of Oceanography, SOA, Qingdao 266100, P.R. China Indonesian throughflow (ITF) is one of the most important currents responsible for transporting heat and moisture from the western Pacific to the Indian Oceans. The ITF is also well-known as effectively in modulating the global climate change with the interactions among ENSO and Asian monsoons. Here we present an AMS 14C dating controlled sea surface temperature (SST) record from core SO184-10043 (07°18.57'S, 105°03.53'E), which was retrieved from 2171m water depth at a north-south depression located at the southeastern offshore area of Sumatera in the eastern Indian Ocean. Based on our high-resolution SST using Mg/Ca analyses based on planktonic foraminifera shells of Globigerinoides ruber and alkenone index, U k'37-SST, oxygen isotope stratigraphy, and AMC 14C age-controls, our records show that, during the past 32,000 years, the SSTs were decreased which imply weaker ITF during Marine Isotope Stage (MIS) 2 and 3. The weaker UTF may respond to strengthened northeast monsoon during the boreal winter. During 21 to 15ka, the southeast monsoon had been stronger and the northeast monsoon was relatively weaker. During 15 to 8ka, rapid sea level rising may allow the opening of the gateways in the Makassar Strait and Lombok Strait that may have further strengthened the ITF. During the early Holocene, the northeast and southeast monsoons seem to be both strengthened. We will discuss the implications of the hydrographic variability and their age uncertainties in this paper during the meeting.

  18. Bayesian integration of radioisotope dating (210Pb, 137Cs, 241Am, 14C) and an 18-20th century mining history of Brotherswater, English Lake District

    Science.gov (United States)

    Schillereff, Daniel; Chiverrell, Richard; Macdonald, Neil; Hooke, Janet; Welsh, Katharine; Piliposyan, Gayane; Appleby, Peter

    2014-05-01

    Lake sediment records are often a useful tool for investigating landscape evolution as geomorphic changes in the catchment are reflected by altered sediment properties in the material transported through the watershed and deposited at the lake bed. Recent research at Brotherswater, an upland waterbody in the Lake District, northwest England, has focused on reconstructing historical floods from their sedimentary signatures and calculating long-term sediment and carbon budgets from fourteen sediment cores extracted from across the basin. Developing accurate chronological control is essential for these tasks. One sediment core (BW11-2; 3.5 m length) from the central basin has been dated using artificial radionuclide measurements (210Pb, 137Cs, 241Am) for the uppermost sediments and radiocarbon (14C) for lower sediments. The core appears to span the past 1500 years, however a number of problems have arisen. We present our explanations for these errors, the independent chronological techniques used to generate an accurate age-depth model for this core and methods for its transferral to the other 13 cores extracted from the basin. Two distinct 137Cs markers, corresponding to the 1986 Chernobyl disaster and 1960s weapons testing, confirm the 210Pb profile for sediment deposition since ~1950, but calculations prior to this appear erroneous, possibly due to a hiatus in the sediment record. We used high-resolution geochemical profiles (measured by XRF) to cross-correlate with a second 210Pb-dated chronology from a more distal location, which returned more sensible results. Unfortunately, the longer 14C sequence exhibits two age-reversals (radiocarbon dates that are too old). We believe the uppermost two dates are erroneous, due to a shift in inflow location as a flood prevention method ~1900 A.D., dated using information from historical maps. The lower age-reversal coincides with greater supply of terrigenous material to the lake (increased Zr, K, Ti concentrations

  19. Dating human DNA with the 14C bomb peak

    Energy Technology Data Exchange (ETDEWEB)

    Kutschera, Walter; Liebl, Jakob; Steier, Peter [VERA Laboratory, University of Vienna, Vienna (Austria)

    2013-07-01

    In 1963 the limited nuclear test ban treaty stopped nuclear weapons testing in the atmosphere. By then the addition from bomb-produced {sup 14}C had doubled the {sup 14}C content of the atmosphere. Through the CO{sub 2} cycle this excess exchanged with the hydrosphere and biosphere leading to a rapidly decreasing {sup 14}C level in the atmosphere. Today we are almost back to the pre-nuclear level. As a consequence all people on Earth who lived during the second half of the 20th century were exposed to this rapidly changing {sup 14}C signal. A few years ago, a group at the Department of Cell and Molecular Biology of the Karolinska Institute in Stockholm started to use the {sup 14}C bomb peak signal in DNA to determine retrospectively the age of cells from various parts of the human body (brain, heart, fat). In a collaboration with this group, we have studied the age of olfactory bulb neurons in the human brain. For this investigation, {sup 14}C AMS measurements were developed at VERA for very small carbon samples in the range from 2 to 4 micrograms. In the presentation the general concept of {sup 14}C bomb peak dating of human DNA and several applications are discussed.

  20. Strategy of valid 14C dates choice in syngenetic permafrost

    Science.gov (United States)

    Vasil'chuk, Y. K.; Vasil'chuk, A. C.

    2014-11-01

    The main problem of radiocarbon dating within permafrost is the uncertain reliability of the 14C dates. Syngenetic sediments contain allochthonous organic deposit that originated at a distance from its present position. Due to the very good preservation of organic materials in permafrost conditions and numerous re-burials of the fossils from ancient deposits into younger ones the dates could be both younger and older than the true age of dated material. The strategy for the most authentic radiocarbon date selection for dating of syncryogenic sediments is considered taking into account the fluvial origin of the syngenetic sediments. The re-deposition of organic material is discussed in terms of cyclic syncryogenic sedimentation and also the possible re-deposition of organic material in subaerial-subaqueous conditions. The advantages and the complications of dating organic micro-inclusions from ice wedges by the accelerator mass spectrometry (AMS) method are discussed applying to true age of dated material search. Radiocarbon dates of different organic materials from the same samples are compared. The younger age of the yedoma from cross-sections of Duvanny Yar in Kolyma River and Mamontova Khayata in the mouth of Lena River is substantiated due to the principle of the choice of the youngest 14C date from the set.

  1. The use of AMS 14C dating to explore issues of occupation and demise at the medieval city of Angkor, Cambodia

    International Nuclear Information System (INIS)

    Penny, Dan; Hua, Quan; Pottier, Christophe; Fletcher, Roland; Barbetti, Mike

    2007-01-01

    Angkorian temples are characterised by one or more encircling moats that are excavated into the alluvial substrate. As a key part of the overall design of the temple, the moats are important symbolically and are presumed to be contemporaneous with the associated temple. They also represent important depositional basins for sediment and other materials and can therefore yield vertical profiles of sediment that has accumulated since the moat was originally excavated. Unconformities in these moat profiles can be dated absolutely using small-sample, high-precision AMS radiocarbon techniques. These unconformities are likely to represent periodic re-excavation or maintenance of the moat and therefore indicate the presence of large, presumably centrally organised workforces. In some instances, presumed anthropogenic unconformities occur centuries after Angkor was supposedly abandoned. In this way, radiocarbon dates themselves are being used as a proxy indicator of cultural activity and are being used to challenge the historiography of Angkor's famous demise

  2. Using of the AMS - 14 C technique for dating of soil charcoals, from holocene period, in the amazon forest(Manaus-Brazil region)

    International Nuclear Information System (INIS)

    Santos, G.M.; Gomes, P.R.S.; Anjos, R.M.; Cordeiro, R.C.; Turcq, B.J.; Sifeddine, A.; Tada, M.L. di; Cresswell, R.G.; Fifield, L.K.

    1999-01-01

    The Accelerator Mass Spectrometry (AMS) technique was used to determine the radiocarbon age of charcoal fragments of soil samples from the Amazon Region near Manaus. The radiocarbon ages are within the 130 - 2400 years range. The interpretation is that these results are evidences of important fire events that occurred mostly during the superior Holocene dry phase. These res had spread out more intensely at the high land areas than at shoals. In this paper there are descriptions of the processes of sample preparation and the procedures for the AMS analysis. (author)

  3. AMS of {sup 14}C at low energies

    Energy Technology Data Exchange (ETDEWEB)

    Suter, M.; Huber, R.; Jacob, S. [ETHZ, Zurich (Switzerland); Synal, H.A. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-09-01

    At the ETH/PSI AMS facility {sup 14}C test measurements have been performed at low terminal voltages of 0.5 and 1 MV in order to study the feasibility of AMS with very small accelerators. These experiments have demonstrated that interfering molecules ({sup 13}CH and {sup 12}CH{sub 2}) in charge states 1{sup +} and 2{sup +} can be destroyed in an adequate Ar gas stripper. These new results imply the feasibility of a new generation of very small accelerator systems for {sup 14}C. (author) 1 fig., 3 refs.

  4. A new 14C AMS facility at IUAC, New Delhi

    International Nuclear Information System (INIS)

    Kumar, Pankaj; Ojha, S.; Sharma, R.; Gargari, S.; Joshi, R.; Chopra, S.; Kanjilal, D.

    2015-01-01

    A new state of art Accelerator Mass Spectrometry (AMS) facility for 14 C has been developed at IUAC. This facility is based on the 0.5 MV Pelletron accelerator and an Automated Graphitization Equipment (AGE). In addition to the 14 C measurements, this system has the capability to perform 10 Be and 26 AI measurements also. The system is called XCAMS i.e., Compact, Accelerator Mass Spectrometer eXtended for 10 Be and 26 AI. A detailed description of the newly developed AMS facility and the recent measurements will be discussed

  5. Application of AMS 14C measurements to criminal investigations

    International Nuclear Information System (INIS)

    Nakamura, T.; Ohta, T.; Nishida, M.; Ikeda, A.; Oda, H.; Kojima, S.; Niu, E.

    2005-01-01

    14 C variations of atmospheric CO 2 as well as carbonaceous materials of human body, such as collagen fractions from teeth and bone, tissue, hair, nail, etc., of modern humans dead or alive, are influenced by 14 C produced artificially by nuclear bomb tests in the atmosphere from late 1950s to early 1960s. By careful investigation of 14 C concentration of tree rings and human tissue samples formed in this time ranges, we can establish a relation between their 14 C concentrations and calendar year. By applying this relation to a sample whose 14 C concentration can be measured, we can estimate the formation age of the sample. In addition, sources of the drugs that were used in some criminal cases can be possibly identified by the analysis of their carbon isotope ratios ( 13 C/ 12 C and 14 C/ 12 C). This method of age determination was applied to a forensic study; i.e., to two similar cases of murder. One of the two cases is for a dead body of a modern human who was killed in 1978 and buried under the floor of the house owned by the murderer. The body was excavated in 2004 according to the confession by the murderer. 14 C abundances of several pieces of hair and one tooth (the third molar) from the body were measured with accelerator mass spectrometry (AMS), and compared with the annual change on concentrations of bomb-produced 14 C. The time of death of the body was estimated to be at around 1977, and her age was from 30 to 37 years old at that time. These estimations were consistent with the real values that were revealed after the case was solved by the confession of the real murderer who gave himself up to the police. For the other case, 14 C analysis was also consistent with the fact revealed by police investigations as well as by the confession of the real murderer.

  6. Forensic applications of {sup 14}C bomb-pulse dating

    Energy Technology Data Exchange (ETDEWEB)

    Zoppi, U. E-mail: ugo@ansto.gov.au; Skopec, Z.; Skopec, J.; Jones, G.; Fink, D.; Hua, Q.; Jacobsen, G.; Tuniz, C.; Williams, A

    2004-08-01

    After a brief review of the basics of {sup 14}C bomb-pulse dating, this paper presents two unique forensic applications. Particular attention is dedicated to the use of the {sup 14}C bomb-pulse to establish the time of harvest of illicit drugs such as heroin and opium. Preliminary measurements of {sup 14}C concentrations in milligram samples taken from seized drugs are presented. {sup 14}C bomb-pulse dating can determine whether drug distribution originates from stockpiles or recent manufacture, and support the action of law enforcement authorities against criminal organisations involved in drug trafficking. In addition, we describe the dating of wine vintages for a number of authenticated single label vintage red wines from the Barossa Valley - South Australia. Our results show that radiocarbon dating can be used to accurately determine wine vintages and therefore reveal the addition of unrelated materials of natural and synthetic origin.

  7. Forensic applications of 14C bomb-pulse dating

    International Nuclear Information System (INIS)

    Zoppi, U.; Skopec, Z.; Skopec, J.; Jones, G.; Fink, D.; Hua, Q.; Jacobsen, G.; Tuniz, C.; Williams, A.

    2004-01-01

    After a brief review of the basics of 14 C bomb-pulse dating, this paper presents two unique forensic applications. Particular attention is dedicated to the use of the 14 C bomb-pulse to establish the time of harvest of illicit drugs such as heroin and opium. Preliminary measurements of 14 C concentrations in milligram samples taken from seized drugs are presented. 14 C bomb-pulse dating can determine whether drug distribution originates from stockpiles or recent manufacture, and support the action of law enforcement authorities against criminal organisations involved in drug trafficking. In addition, we describe the dating of wine vintages for a number of authenticated single label vintage red wines from the Barossa Valley - South Australia. Our results show that radiocarbon dating can be used to accurately determine wine vintages and therefore reveal the addition of unrelated materials of natural and synthetic origin

  8. Forensic applications of 14C bomb-pulse dating

    Science.gov (United States)

    Zoppi, U.; Skopec, Z.; Skopec, J.; Jones, G.; Fink, D.; Hua, Q.; Jacobsen, G.; Tuniz, C.; Williams, A.

    2004-08-01

    After a brief review of the basics of 14C bomb-pulse dating, this paper presents two unique forensic applications. Particular attention is dedicated to the use of the 14C bomb-pulse to establish the time of harvest of illicit drugs such as heroin and opium. Preliminary measurements of 14C concentrations in milligram samples taken from seized drugs are presented. 14C bomb-pulse dating can determine whether drug distribution originates from stockpiles or recent manufacture, and support the action of law enforcement authorities against criminal organisations involved in drug trafficking. In addition, we describe the dating of wine vintages for a number of authenticated single label vintage red wines from the Barossa Valley - South Australia. Our results show that radiocarbon dating can be used to accurately determine wine vintages and therefore reveal the addition of unrelated materials of natural and synthetic origin.

  9. {sup 14} C dating by using mass spectrometry with particle accelerator; Datacao por {sup 14} C utilizando espectrometria de massa com acelerador de particulas

    Energy Technology Data Exchange (ETDEWEB)

    Santos, G.M.; Gomes, P.R.S. [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Inst. de Fisica]. E-mail: paulogom@if.uff.br; Yokoyama, Y. [Australian National Univ., Canberra (Australia). Research School of Earth Science; Tada, M.L. di; Cresswell, R.G.; Fifield, L.K. [Australian National Univ., Canberra (Australia). Dept. of Nuclear Physics

    1999-03-01

    The different aspects concerning the {sup 14} C dating are described, including the cosmogenic origin of {sup 14} C, its production and absorption by matter, the procedures to be followed for the age determination and the associated errors, particularly by the Accelerator Mass Spectrometry (AMS) technique, and the different steps of the sample preparation process. (author)

  10. Physical Research Laboratory radiocarbon 14C dates : CS-I

    International Nuclear Information System (INIS)

    Agrawal, D.P.; Krishnamurthy, R.V.; Kusumgar, Sheela; Pant, R.K.

    1978-01-01

    The 14 C dates of archaeological samples measured at the Radiocarbon Laboratory of the Physical Research Laboratory, Ahmedabad are presented. Samples were converted into methane and measured in gas proportional counters. Ninety-five percent activity of NBS oxalic acid was used as modern standard. The dates in years B.P. are given for each sample based on the half-life values of 5568 +- 30 years and 5730 +- 40 years, the latter within parenthesis. The dates are not calibrated for 14 C/ 12 C variations. To convert the dates into AD/BC scale, 1950 AD should be used as reference year. A number of 14 C dates (PRL-81, -83, -67, -68) now confirm that the Painted Grey Ware culture extended upto the 3rd century BC. Some of the dates from Barkhera (PRL-113), Bateshwar (PRL-200), Bhimbetka (PRL-17) and Koldihawa (PRL-100, 101) are older than normally expected, probably indicative of some hitherto unknown basal cultures in these regions. 14 C dates on in situ Megalithic materials do not seem to go beyond 200 BC. (author)

  11. Direct dating of archaeological pottery by compound-specific 14C analysis of preserved lipids.

    Science.gov (United States)

    Stott, Andrew W; Berstan, Robert; Evershed, Richard P; Bronk-Ramsey, Christopher; Hedges, Robert E M; Humm, Martin J

    2003-10-01

    A methodology is described demonstrating the utility of the compound-specific 14C technique as a direct means of dating archaeological pottery. The method uses automated preparative capillary gas chromatography employing wide-bore capillary columns to isolate individual compounds from lipid extracts of archaeological potsherds in high purity (>95%) and amounts (>200 microg) sufficient for radiocarbon dating using accelerator mass spectrometry (AMS). A protocol was developed and tested on n-alkanes and n-carboxylic acids possessing a broad range of 14C ages. Analytical blanks and controls allowed background 14C measurements to be assessed and potential sources of errors to be detected, i.e., contamination with modern or dead 14C, isotopic fraction effects, etc. A "Russian doll" method was developed to transfer isolated target compounds onto tin powder/capsules prior to combustion and AMS analyses. The major advantage of the compound-specific technique is that 14C dates obtained for individual compounds can be directly linked to the commodities processed in the vessels during their use, e.g., animal fats. The compound-specific 14C dating protocol was validated on a suite of ancient pottery whose predicted ages spanned a 5000-year date range. Initial results indicate that meaningful correlations can be obtained between the predicted date of pottery and that of the preserved lipids. These findings constitute an important step forward to the direct dating of archaeological pottery.

  12. May {sup 14}C be used to date contemporary art?

    Energy Technology Data Exchange (ETDEWEB)

    Fedi, M.E., E-mail: fedi@fi.infn.it [INFN Sezione di Firenze, Via Sansone 1, 50019 Sesto Fiorentino (Italy); Caforio, L. [INFN Sezione di Firenze, Via Sansone 1, 50019 Sesto Fiorentino (Italy); Dipartimento di Fisica, Universita di Ferrara, Via Saragat 1, 44100 Ferrara (Italy); Mando, P.A. [INFN Sezione di Firenze, Via Sansone 1, 50019 Sesto Fiorentino (Italy); Dipartimento di Fisica e Astronomia, Universita di Firenze, Via Sansone 1, 50019 Sesto Fiorentino (Italy); Petrucci, F. [Dipartimento di Fisica, Universita di Ferrara, Via Saragat 1, 44100 Ferrara (Italy); INFN Sezione di Ferrara, Via Saragat 1, 44100 Ferrara (Italy); Taccetti, F. [INFN Sezione di Firenze, Via Sansone 1, 50019 Sesto Fiorentino (Italy)

    2013-01-15

    The use of radiocarbon in forensics is by now widespread, thanks to the so-called bomb peak, which makes it possible to perform high-precision dating. Since 1955, {sup 14}C concentration in the atmosphere had strongly increased due to nuclear explosions, reaching its maximum value in 1963-1965. After the Nuclear Test Ban Treaty, {sup 14}C started to decrease as a consequence of the exchanges between atmosphere and the other natural carbon reservoirs. Nowadays, it is still slightly above the pre-bomb value. The work presented in this paper is based on the idea of exploiting the bomb peak to 'precisely' date works of contemporary art, with the aim at identifying possible fakes. We analysed two kinds of materials from the 20th century: newspapers and painting canvases. Newspaper samples were taken because they might in principle be considered to represent dated samples (considering the date on the issues). Our data (28 samples) show a trend similar to atmospheric data in the literature, although with some differences; the paper peak is flatter and shifted towards more recent years (about five years) with respect to the atmospheric data. This can be explained by taking paper manufacturing processes into account. As to the canvas samples, the measured {sup 14}C concentrations were generally reasonably consistent with the expected concentrations (based on the year on the paintings). However, this does not indicate that the interpretation of the results is simpler and more straightforward. Obviously, we only measure the {sup 14}C concentration of the fibre used for the canvas, which does not necessarily measure the date the painting was manufactured. In this paper, sample preparation and experimental results will be discussed, in order to show the potential as well as the limitations of radiocarbon to date contemporary art.

  13. May 14C be used to date contemporary art?

    International Nuclear Information System (INIS)

    Fedi, M.E.; Caforio, L.; Mandò, P.A.; Petrucci, F.; Taccetti, F.

    2013-01-01

    The use of radiocarbon in forensics is by now widespread, thanks to the so-called bomb peak, which makes it possible to perform high-precision dating. Since 1955, 14 C concentration in the atmosphere had strongly increased due to nuclear explosions, reaching its maximum value in 1963–1965. After the Nuclear Test Ban Treaty, 14 C started to decrease as a consequence of the exchanges between atmosphere and the other natural carbon reservoirs. Nowadays, it is still slightly above the pre-bomb value. The work presented in this paper is based on the idea of exploiting the bomb peak to “precisely” date works of contemporary art, with the aim at identifying possible fakes. We analysed two kinds of materials from the 20th century: newspapers and painting canvases. Newspaper samples were taken because they might in principle be considered to represent dated samples (considering the date on the issues). Our data (28 samples) show a trend similar to atmospheric data in the literature, although with some differences; the paper peak is flatter and shifted towards more recent years (about five years) with respect to the atmospheric data. This can be explained by taking paper manufacturing processes into account. As to the canvas samples, the measured 14 C concentrations were generally reasonably consistent with the expected concentrations (based on the year on the paintings). However, this does not indicate that the interpretation of the results is simpler and more straightforward. Obviously, we only measure the 14 C concentration of the fibre used for the canvas, which does not necessarily measure the date the painting was manufactured. In this paper, sample preparation and experimental results will be discussed, in order to show the potential as well as the limitations of radiocarbon to date contemporary art.

  14. AMS-14C analysis of modern teeth: A comparison between two sample preparation techniques

    Science.gov (United States)

    Solis, C.; Solis-Meza, E.; Morales, M. E.; Rodriguez-Ceja, M.; Martínez-Carrillo, M. A.; Garcia-Calderon, D.; Huerta, A.; Chávez, E.

    2017-09-01

    AMS-14C analysis of modern teeth has become important for forensic studies. 14C content in human teeth reflects the 14C atmospheric concentration during its formation and allows the calculation of the actual year of birth. Through AMS, it is possible to measure the 14C concentrations in a tissue with high precision. However, there is a debate about which should be the best fraction for teeth carbon dating: collagen or enamel. This work focuses on the results obtained from enamel and collagen extracted from Mexican people in order to compare them. Collagen from dental pieces donated from people older than 60-years-old have been included to understand the turnover process and usefulness of collagen to determine the date of birth. Our results indicate that when a single dental piece is available, enamel method allows the determination of the tooth formation date. Dating collagen of the same tooth helps to discriminate if the formation date belongs to the left or the right side of the peak bomb, but also corroborates, the ages obtained through enamel analysis.

  15. Dating of groundwater with tritium and 14C

    International Nuclear Information System (INIS)

    Muennich, K.O.; Roether, W.; Thilo, L.

    1967-01-01

    Shallow groundwater can be dated with some accuracy on the basis of its bomb tritium content if the unsaturated soil cover and the aquifer itself is sufficiently homogeneous. A few examples from the Rhine valley are presented. The decrease in tritium level from the water table to a few metres below is nearly two orders of magnitude. Agreement between the measured or estimated variation of bomb tritium in rain during the past decade and the tritium found in shallow groundwater can be obtained if one takes into account that (a) practically no summer rain reaches the water table, and (b) water is mixed by diffusion. Both effects can also be observed in the soil moisture of the unsaturated soil above the water table. Carbon-14 increase in groundwater due to bombs is delayed compared to tritium, the reasons being delay in the biological system and exchange with the carbonate in the soil. Nevertheless lysimeters show a marked increase of 14 C, which depends on the plant cover, being high in a plant-covered lysimeter and low in a bare one. A simple model is presented, which allows the evaluation of the influence of exchange on the 14 C age obtained. It turns out that the deviation from the true age depends on the ratio of the carbonate content in the aquifer material to the carbonate content of the water, on the specific contact surface or the grain size but not on the groundwater velocity. On the basis of this model the experimental finding that 14 C ages are usually in agreement with other age estimates despite the loss by exchange is plausible owing to the fact that only material of sufficiently coarse grain size can make up a reasonable aquifer. Assuming only exchange with a monomolecular surface layer of the carbonate grains one finds that the 14 C age is likely to differ by not more than a factor of two in the most unfavourable case. Under natural conditions (steady state of cosmic-ray-produced 14 C) the 14 C content of shallow groundwater is hardly influenced at

  16. Application of AMS 14C measurements to criminal investigations

    International Nuclear Information System (INIS)

    Nakamura, T.; Ohta, T.; Nishida, M.; Rakowski, A.; Ikeda, A.; Oda, H.; Kojima, S.

    2007-01-01

    14 C variations of atmospheric CO 2 as well as carbonaceous fraction of living materials, such as collagen from tooth and bone, tissue, skin, hair, nail, etc., of modern humans are influenced by 14 C produced artificially by nuclear bomb tests in the atmosphere from late 1950s to early 1960s. By careful investigation of 14 C concentration of tree rings and human body samples formed in this time intervals, we can establish a relationship of their 14 C concentrations with calendar year. By applying this relation to a sample whose 14 C concentration can be measured, we can estimate the formation age of the sample. In addition, sources of the chemicals that were used in some criminal cases can be possibly identified, by their carbon isotope ratios ( 13 C/ 12 C and 14 C/ 12 C). This method of age determination has been applied to a forensic study, i.e., two criminal cases of murder. For each case, by comparing the measured 14 C abundances of several pieces of hair and one tooth (the third molar) from the body with the annual change on concentrations of bomb-produced 14 C, the time of death of the body and the age of the victim were estimated. The estimated values were consistent with the real ones that were revealed by the confession of the real murderers. (author)

  17. The first millennium AD climate fluctuations in the Tavoliere Plain (Apulia, Italy): New preliminary data from the 14C AMS-dated plant remains from the archaeological site of Faragola

    International Nuclear Information System (INIS)

    Fiorentino, G.; Caracuta, V.; Volpe, G.; Turchiano, M.; Quarta, G.; D'Elia, M.; Calcagnile, L.

    2010-01-01

    The identification of ancient climate fluctuations represents an hard challenge for studies intended to outline the human-environment interaction in fragile ecosystems. The aim of this work is to test the potentialities of carbon stable isotopic content of AMS-dated archaeological plant remains as tool to infer variations in rainfall/temperature regimes. The results obtained in the analysis of the carbon stable isotopic content of 10 plant remains selected among the archaeobotanical remains collected at the archaeological site in Faragola (Apulia, Italy) and radiocarbon-dated by AMS are presented. The variation of δ 13 C values was considered on a chronological scale covering a time range comprised between the II century BC and the VII century AD. The obtained patterns were also compared with local and global-scale palaeoclimatic records.

  18. Tips and traps in the 14C bio-AMS preparation laboratory

    International Nuclear Information System (INIS)

    Buchholz, Bruce A.; Freeman, Stewart P.H.T.; Haack, Kurt W.; Vogel, John S.

    2000-01-01

    Maintaining a contamination free sample preparation lab for biological 14 C AMS requires the same or more diligence as a radiocarbon dating prep lab. Isotope ratios of materials routinely range over 4-8 orders of magnitude in a single experiment, dosing solutions contain thousands of DPM and gels used to separate proteins possess 14 C ratios of 1 amol 14 C/mg C. Radiocarbon contamination is a legacy of earlier tracer work in most biological laboratories, even if they were never hot labs. Removable surface contamination can be found and monitored using swipes. Contamination can be found on any surface routinely touched: door knobs, light switches, drawer handles, water faucets. In general, all surfaces routinely touched need to be covered with paper, foil or plastic that can be changed frequently. Shared air supplies can also present problems by distributing hot aerosols throughout a building. Aerosols can be monitored for 14 C content using graphitized coal or fullerene soot mixed with metal powder as an absorber. The monitors can be set out in work spaces for 1-2 weeks and measured by AMS with regular samples. Frequent air changes help minimize aerosol contamination in many cases. Cross-contamination of samples can be minimized by using disposable plastic or glassware in the prep lab, isolating samples from the air when possible and using positive displacement pipettors

  19. The compact 14C AMS facility of Paleo Labo Co., Ltd., Japan

    International Nuclear Information System (INIS)

    Kobayashi, Koichi; Niu, Etsuko; Itoh, Shigeru; Yamagata, Hideki; Lomtatidze, Zaur; Jorjoliani, Ineza; Nakamura, Kentaro; Fujine, Hisashi

    2007-01-01

    A compact AMS system was installed by a private company in Japan for a 14 C dating business. Since this system was designed to be very compact with a low voltage accelerator, it has unique features compared to larger AMS systems. For example, the stripper gas pressure has to be maintained at a high level to dissociate molecular ions. However, it cannot be too high because ion transmission decreases at higher stripper gas pressures due to increased angular straggling of the ions scattered by the high density stripper gas. The optimum pressure of the stripper gas for the lowest background and the highest transmission was investigated. With all the features of the compact system, the produced measurements can be of quite high precision. In the ten months after the installation of the equipment in November 2004, we have measured more than 1400 dating samples

  20. Direct 14C dating of megalithic paints from NW Iberia

    Directory of Open Access Journals (Sweden)

    Carrera Ramírez, Fernando

    2002-06-01

    Full Text Available In this paper we present 5 AMS dates obtained from the paintings found on the uprights of 4 Galician megalithic graves. The results have shown that this art belongs roughly to the first half of the 4th millennium BC and pose the question of the contemporaneity of the building of the chambers and the execution of the paintings and also the occurrence of more than one episode of decoration in them.

    En este trabajo damos a conocer cinco dataciones radiocarbónicas AMS obtenidas a partir de muestras de pintura de cuatro monumentos megalíticos gallegos. Los resultados obtenidos confirman la utilidad de este tipo de análisis a la hora de trazar la cronología de estas manifestaciones artísticas (en torno a la primera mitad del IV milenio AC y plantean además nuevas cuestiones acerca de la simultaneidad entre la pintura y la construcción de las cámaras, así como la existencia de dos o más episodios pictóricos.

  1. Tips and traps in the 14C Bio-AMS preparation laboratory (WSam 7)

    International Nuclear Information System (INIS)

    Buchholz, B A; Haack, K W; Stewart, P H; Vogel, J S

    1999-01-01

    Maintaining a contamination free sample preparation lab for biological 14 C AMS requires the same or more diligence as a radiocarbon dating prep lab. Isotope ratios of materials routinely range over 4-8 orders of magnitude in a single experiment, dosing solutions contain thousands of DPM and gels used to separate proteins possess 14 C ratios of 1pMC. Radiocarbon contamination is a legacy of earlier tracer work in most biological laboratories, even if they were never hot labs. Removable surface contamination can be found and monitored using swipes. Contamination can be found on any surface routinely touched: door knobs, light switches, drawer handles, water faucets. In general, all surfaces routinely touched need to be covered with paper, foil, or plastic that can be changed frequently. Shared air supplies can also present problems by distributing hot aerosols throughout a building. Aerosols can be monitored for 14 C content using graphitized coal or fullerene soot mixed with metal powder as an absorber. The monitors can be set out in work spaces for 1-2 weeks and measured by AMS with regular samples. Frequent air changes help minimize aerosol contamination in many cases. Cross contamination of samples can be minimized by using disposable plastic or glassware in the prep lab, isolating samples from the air when possible and using positive displacement pipetters

  2. Applications of 14C - AMS on Archaeology, Climate, Environment, Geology, Oceanography and Biology

    International Nuclear Information System (INIS)

    Gomes, P. R. S.; Macario, K. D.; Anjos, R. M.

    2007-01-01

    In this contribution we describe several experiments on 14 C-AMS (Accelerator Mass Spectrometry) related to historical, ecological and environmental questions. We discuss the chronology of prehistoric settlements of the central-south Brazilian coast. The unexpected result pulls back by some two thousand years the antiquity consensually accepted for the settlement of that region. We performed an experiment concerning the isotopic signature of the local waters of an important Brazilian coastal upwelling. The results of 14 C-AMS measurements in seaweed tissue show differences in the isotopic signature of the water sources. The present results contribute to opening new perspectives for the use of 14 C as a tracer of the biological production in upwelling areas all over the world. We performed experiments on climate at the Amazon region. At remote lakes of the Amazon region, the Hg accumulation rate archived in sediment cores is a powerful tool for the interpretation of the paleoclimatology and paleoecology of the region. Different sedimentation regimes are observed from ∼41500 yr. BP to the present. The understanding of sea-level fluctuations are fundamental for human occupation of littoral areas and hydrocarbon industry on offshore exploration. We performed radiocarbon dating of foraminifera shell samples, collected in upper slope of Campos Basin, in Southern Brazil. The mean accumulation ratio for the whole column is 6.17 cm/1000 years. Fluctuations in this mean values indicate that the ocean bottom dynamics has some variation during the period. (Author)

  3. Deep water ventilation in the northwestern North Pacific during the last deglaciation and the early Holocene (15-5 cal. kyr B.P.) based on AMS 14C dating

    International Nuclear Information System (INIS)

    Minoshima, Kayo; Kawahata, Hodaka; Irino, Tomohisa; Ikehara, Ken; Aoki, Kaori; Uchida, Masao; Yoneda, Minoru; Shibata, Yasuyuki

    2007-01-01

    The difference between benthic and planktonic foraminifera radiocarbon (B-P 14 C) age differences in core PC6 (40 o 23.89' N, 143 o 29.87' E) retrieved from the northwestern North Pacific provide a clue to the reconstruction of deep water circulation during the last deglaciation and the early Holocene (15-5 cal. kyr B.P.). The observed B-P 14 C age differences ranged from 1030 to 1630 years, which are comparable to the present-day apparent ventilation age. It suggested that the ventilation generally remained similar during 15-5 cal. kyr B.P. However, B-P 14 C age difference slightly reduced at 14.6 cal. kyr B.P., indicating that the higher ventilation temporality could have occurred in the northwestern North Pacific (∼2200 m water depth)

  4. 14C dating of the Early to Late Bronze Age stratigraphic sequence of Aegina Kolonna, Greece

    International Nuclear Information System (INIS)

    Wild, E.M.; Gauss, W.; Forstenpointner, G.; Lindblom, M.; Smetana, R.; Steier, P.; Thanheiser, U.; Weninger, F.

    2010-01-01

    Aegina Kolonna, located in the center of the Saronic Gulf in the Aegean Mediterranean (Greece), is one of the major archaeological sites of the Aegean Bronze Age with a continuous stratigraphic settlement sequence from the Late Neolithic to the Late Bronze Age. Due to its position next to the maritime cross roads between central mainland Greece, the northeast Peloponnese, the Cyclades and Crete, the island played an important role in the trade between these regions. In the course of new excavations, which focused on the exploration of the Early, Middle and Late Bronze Age at Kolonna, several short lived samples from different settlement phases have been 14 C-dated with the AMS method at the VERA laboratory. Bayesian sequencing of the 14 C data according to the stratigraphic position of the samples in the profile was performed to enable estimates of the transition time between the cultural phases. The Aegina Kolonna 14 C sequence is one of the longest existing so far for the Aegean Bronze Age, and therefore of major importance for the absolute Bronze Age chronology in this region. Preliminary results indicate that the Middle Helladic period seems to have started earlier and lasted longer than traditionally assumed. Further, at the present stage of our investigation we can give also a very tentative time frame for the Santorini volcanic eruption which seems to be in agreement with the science derived VDL date.

  5. New applications of 14C measurements at the Lund AMS Facility

    International Nuclear Information System (INIS)

    Stenstroem, K.

    1995-11-01

    Some new applications of accelerator mass spectroscopy (AMS) with 14 C are presented. In the first part the sample preparation used for production of elemental carbon at the Lund AMS facility is described. The second part concerns the release of 14 C from nuclear power plants. In a one-year study, the total airborne discharge of 14 C from two Swedish reactors was measured. In another study, the fraction of 14 CO 2 of the total airborne 14 C release was determined. The third part of the thesis involves the use of 14 C in nuclear medicine. The long-term retention of 14 C-labelled triolein after a fat-malabsorption test has been investigated by means of AMS by analysis of expired CO 2 . The possibilities of using ultra-low amounts of activity for fat-malabsorption tests, employing AMS technique, is demonstrated. In the last part AMS and 14 C-labelled tracers are used in food chemistry studies of interactions between foods and packaging materials. 22 refs, 8 figs, 2 tabs

  6. Changes in solar activity and Holocene climatic shifts derived from 14C wiggle-match dated peat deposits

    NARCIS (Netherlands)

    Mauquoy, Dmitri; Geel, Bas van; Blaauw, Maarten; Speranza, Alessandra; Plicht, Johannes van der

    2004-01-01

    Closely spaced sequences of accelerator mass spectrometer (AMS) 14C dates of peat deposits display century-scale wiggles which can be fitted to the radiocarbon calibration curve. By wiggle-matching such sequences, high-precision calendar age chronologies can be generated which show that changes in

  7. Studies on 129I and 14C in environmental samples by AMS

    International Nuclear Information System (INIS)

    Muramatsu, Yasuyuki

    2010-01-01

    and 127 I in soil were also studied. In order to know the secular variation of 14 C concentrations in the atmosphere, we have determined 14 C/ 12 C ratios in a Yaku cedar (age: 1632 year-old) from Yaku-Island (Kagoshima Prefecture, Japan), where there are many old cedar trees. Selected annual tree ring samples during 560-800 A.D. were used. In this period, there is very little data about secular variation of radiocarbon contents measured for Japanese samples. In the analysis, we have developed an apparatus (glass vacuum line) for purifying carbon from samples of single rings to make graphite targets for AMS. Using a small sample size (about 0.03g of cellulose sample), we could measure 14 C/ 12 C ratios with reasonable precision and accuracy by AMS at MALT, University of Tokyo. Results obtained in this study agreed with a 14 C pattern reported by IntCal04. However, if we see details, our data showed a wide range and a short term trend of the variation. This is because resolution of our data (single tree ring measurement) is higher than those of IntCal04 in which tree rings of ten years were combined. Around 700 A.D., Δ 14 C maximum is observed. It is interesting to note that there was a cold period around this age, suggesting possible relationships between the solar activity and the climate. Our data should also be useful in Japanese calibration data for the dating of archaeological findings in the above mentioned period. (author)

  8. Late Quaternary extinctions: The promise of TAMS 14C dating

    International Nuclear Information System (INIS)

    Martin, P.S.

    1987-01-01

    In the last 30 000 years late Quaternary extinctions eliminated over two-thirds of the large land mammals of America and Australia and most of the endemic land vertebrates on oceanic islands. Specimens of extinct animals yielding too little organic material for measurement in decay counters are suitable for TAMS dating. Initial results support older evidence of an extinction chronology that was catastrophic regionally, transgressive globally, and linked to the spread of prehistoric people. (orig.)

  9. Mass Balance Model, A study of contamination effects in AMS 14C sample analysis

    NARCIS (Netherlands)

    Prokopiou, Markella

    2010-01-01

    In this training thesis a background correction analysis, also known as mass balance model, was implemented to study the contamination effects in AMS 14C sample processing. A variety of backgrounds and standards with sizes ranging from 50 μg C to 1500 μg

  10. AMS 14C measurements for tree-ring samples from Japanese woods from 4c AD to 8c AD

    International Nuclear Information System (INIS)

    Ozaki, Hiromasa; Sakamoto, Minoru; Imamura, Mineo; Mitsutani, Takumi

    2010-01-01

    Regional offsets of atmospheric 14 C concentration, as represented by differences from IntCal calibration datasets, are discussed at times in relation to universal use of international radiocarbon calibration curve. In the construction of IntCal, 14 C contents of contemporaneous tree-ring samples from different regions in the northern hemisphere have been used, because the regional differences were indistinguishable from errors of measurements. Nowadays, high-precision 14 C results can be obtained much more easily than before, so more attention should be paid to the possible regional offsets. Most parts of IntCal has been constructed by using 14 C contents of tree-ring samples from woods in high latitude of Europe and North America, which are farthest from Japan in the northern hemisphere. So far, we have measured 14 C contents of tree-ring samples from Japanese wood samples dendrochronologically dated from 11th century BC to 4th century AD in order to investigate regional offset in Japan. Although the obtained results agreed well with IntCal in general, there were some periods when the 14 C contents differ significantly from IntCal. In this paper, we report the new results of AMS 14 C measurement for Japanese tree-ring samples ranging from 4th century AD to 8th century AD. The results show a significant disagreement with IntCal at around 630 AD. Similar difference was indicated by 14 C contents of tree-ring samples from other Japanese woods (Imamura et al., 2007). So it is certain that the regional offset in Japan exists at around 630 AD. (author)

  11. The remarkable metrological history of 14C dating: from ancient Egyptian artifacts to particles of soot and grains of pollen

    International Nuclear Information System (INIS)

    Currie, L.A.

    2002-01-01

    . Sensitivity enhancement by some six orders of magnitude was the result, where 14 C atoms are measured directly by accelerator mass spectrometry (AMS), in place of beta particle (decay) counting. (Apart from differences in detection efficiency, the relative sensitivity derives from the first order relationship between the nuclear disintegration rate and the ratio of the 14 C atom concentration to the mean life.) The resultant ability to date ca. 100 μg of carbon has fostered major developments in 'molecular dating' (e.g., via GC/AMS) that have had a profound impact on artifact dating accuracy, and provided new insights into the sources, transport, and age of individual carbonaceous species in the environment. The talk concluded with some current applications of the advanced 14 C metrology, such as the dating of individual amino acids in prehistoric bones, and efforts to extract the recent history of fossil and biomass burning from soot particles trapped in polar and mid-latitude ice cores. (author)

  12. Effect of HF leaching on {sup 14}C dates of pottery

    Energy Technology Data Exchange (ETDEWEB)

    Goslar, Tomasz, E-mail: goslar@radiocarbon.pl [Faculty of Physics, Adam Mickiewicz University, ul. Umultowska 85, 61-614 Poznan (Poland); Poznan Radiocarbon Laboratory, ul. Rubiez 46, 61-612 Poznan (Poland); Kozlowski, Janusz [Institute of Archaeology, Jagiellonian University, ul. Golebia 11, 30-007 Krakow (Poland); Szmyt, Marzena [Institute for Eastern Studies, Adam Mickiewicz University, ul. 28 Czerwca 1956 nr 198, 61-486 Poznan (Poland); Czernik, Justyna [Poznan Radiocarbon Laboratory, ul. Rubiez 46, 61-612 Poznan (Poland)

    2013-01-15

    This paper presents the experiments with {sup 14}C dating of two potsherds, which contained carbon dispersed rather homogeneously in their clay fabric. After AAA treatment, the potsherds still appeared to be contaminated with young carbon, presumably connected with humic acids. To make removal of humic acids more effective, we treated the sherds with HF acid of different concentration. The {sup 14}C results obtained demonstrate that HF treatment indeed helps to remove humic contaminants, but it also mobilizes carbon bound to raw clay, which may make {sup 14}C dates too old. We conclude therefore, that using a simple combination of HF and AAA treatment seems insufficient in reliable {sup 14}C dating of carbon homogeneously dispersed in the volume of potsherds.

  13. A new procedure for extraction of collagen from modern and archaeological bones for 14C dating.

    Science.gov (United States)

    Maspero, F; Sala, S; Fedi, M E; Martini, M; Papagni, A

    2011-10-01

    Bones are potentially the best age indicators in a stratigraphic study, because they are closely related to the layer in which they are found. Collagen is the most suitable fraction and is the material normally used in radiocarbon dating. Bone contaminants can strongly alter the carbon isotopic fraction values of the samples, so chemical pretreatment for (14)C dating by accelerator mass spectrometry (AMS) is essential. The most widespread method for collagen extraction is based on the Longin procedure, which consists in HCl demineralization to dissolve the inorganic phase of the samples, followed by dissolution of collagen in a weak acid solution. In this work the possible side effects of this procedure on a modern bone are presented; the extracted collagen was analyzed by ATR-IR spectroscopy. An alternative procedure, based on use of HF instead of HCl, to minimize unwanted degradation of the organic fraction, is also given. A study by ATR-IR spectroscopic analysis of collagen collected after different demineralization times and with different acid volumes, and a study of an archaeological sample, are also presented.

  14. Applications of 14C-AMS on archaeology, climate, environment, geology, oceanography and biology

    International Nuclear Information System (INIS)

    Gomes, P.R.S.; Anjos, R.M.; Macario, K.D.; Santos, G.M.

    2005-01-01

    The first experiment discusses the chronology of prehistoric settlements of the central-south Brazilian coast. In the southern Brazilian coast there is a high density of these shellmounds, dated in general between 6,000 and 2,000 BP. A charcoal sample from a coastal shellmound of Rio de Janeiro State was dated by 14 C-AMS to 7,860±80 years BP. This is an unexpected result that pulls back by some two thousand years the antiquity consensually accepted for the settlement of that region. We performed an experiment concerning the isotopic signature of the local waters of an important Brazilian coastal upwelling, located in Arraial do Cabo, R.J., with applications in the fields of Oceanography and Marine Ecology. We assess the contribution of the wind-driven coastal upwelling of Arraial do Cabo to the local biological production. The variation of the carbon isotopic compositions was investigated in a population of a seaweed. Upwelling events were simulated in the laboratory, in order to study three regimes: total upwelling (SACW), partial upwelling (mixed water) and no-upwelling (TW). Water samples were collected at 70 m depth (SACW) and at 10 m (TW). The seaweed was cultivated during seven days, in controlled conditions, into the three mentioned types of water. The results of 14 C-AMS measurements in the seaweed tissue show a clear indication of difference in the isotopic signature of the water sources, allowing to infer the differences of the water sources. We believe that the present results contribute to opening new perspectives for the use of 14 C as a tracer of the biological production in upwelling areas all over the world. The next reported experiment is on climate at the Amazon region. An increase in the Hg flux is a strong indicator of disturbance in a forest ecosystem related to abrupt changes in the water balance, and its changes reflect changes in the ocean and average regional temperatures. In regions where the geological background of mercury is

  15. A New 14C-AMS Facility at UFF- Niteroi, Brazil

    International Nuclear Information System (INIS)

    Gomes, P. R. S.; Macario, K. D.; Anjos, R. M.; Linares, R.; Carvalho, C.; Queiroz, E.

    2010-01-01

    We report a new Accelerator Mass Spectrometry facility at the Physics Institute of Fluminense Federal University in Brazil, the Nuclear Chronology Laboratory - LACRON. The sample preparation laboratory is ready to perform chemical treatment through graphitization and the acquisition of a Single Stage Accelerator Mass Spectrometry System is in progress. LACRON will be the first independent laboratory to perform the 14 C-AMS technique not only in Brazil but in Latin America.

  16. A New 14C-AMS Facility at UFF- Niteroi, Brazil

    Science.gov (United States)

    Gomes, P. R. S.; Macario, K. D.; Anjos, R. M.; Linares, R.; Carvalho, C.; Queiroz, E.

    2010-08-01

    We report a new Accelerator Mass Spectrometry facility at the Physics Institute of Fluminense Federal University in Brazil, the Nuclear Chronology Laboratory—LACRON. The sample preparation laboratory is ready to perform chemical treatment through graphitization and the acquisition of a Single Stage Accelerator Mass Spectrometry System is in progress. LACRON will be the first independent laboratory to perform the 14C-AMS technique not only in Brazil but in Latin America.

  17. Science that connects the past and the future. Fifty years of 14C dating

    International Nuclear Information System (INIS)

    Imamura, M.

    2006-01-01

    Major contribution of radiochemistry in archaeological sciences is the dating which provides the most essential information in studies of prehistory. In particular the method of 14 C dating revolutionized the theory of civilization in the world. In this talk I will review 50 years of 14 C dating, techniques and applications, and then the possibilities in contemporary world. The technical developments are featured by ultra-sensitive method of accelerator mass spectrometry in 1977 and its developments, and an introduction of international calibration datasets for 14 C dates started in 1986. Both contributed greatly to improvements in versatility and precision for dating. As for the applications, several interesting topics are reviewed such as the origin of agriculture and its propagation in the western world, the oldest pottery production in Japanese archipelago and its relation to world climate, paddy-rice agriculture and its propagation in Japanese archipelago. Since 14 C studies in nature is also well known as key information on carbon dynamics in earth's surface, it may be said that 14 C play an extraordinary role in understanding our past, present and the future. (author)

  18. An integrated data-analysis and database system for AMS {sup 14}C

    Energy Technology Data Exchange (ETDEWEB)

    Kjeldsen, Henrik, E-mail: kjeldsen@phys.au.d [AMS 14C Dating Centre, Department of Physics and Astronomy, Aarhus University, Aarhus (Denmark); Olsen, Jesper [Department of Earth Sciences, Aarhus University, Aarhus (Denmark); Heinemeier, Jan [AMS 14C Dating Centre, Department of Physics and Astronomy, Aarhus University, Aarhus (Denmark)

    2010-04-15

    AMSdata is the name of a combined database and data-analysis system for AMS {sup 14}C and stable-isotope work that has been developed at Aarhus University. The system (1) contains routines for data analysis of AMS and MS data, (2) allows a flexible and accurate description of sample extraction and pretreatment, also when samples are split into several fractions, and (3) keeps track of all measured, calculated and attributed data. The structure of the database is flexible and allows an unlimited number of measurement and pretreatment procedures. The AMS {sup 14}C data analysis routine is fairly advanced and flexible, and it can be easily optimized for different kinds of measuring processes. Technically, the system is based on a Microsoft SQL server and includes stored SQL procedures for the data analysis. Microsoft Office Access is used for the (graphical) user interface, and in addition Excel, Word and Origin are exploited for input and output of data, e.g. for plotting data during data analysis.

  19. An integrated data-analysis and database system for AMS 14C

    International Nuclear Information System (INIS)

    Kjeldsen, Henrik; Olsen, Jesper; Heinemeier, Jan

    2010-01-01

    AMSdata is the name of a combined database and data-analysis system for AMS 14 C and stable-isotope work that has been developed at Aarhus University. The system (1) contains routines for data analysis of AMS and MS data, (2) allows a flexible and accurate description of sample extraction and pretreatment, also when samples are split into several fractions, and (3) keeps track of all measured, calculated and attributed data. The structure of the database is flexible and allows an unlimited number of measurement and pretreatment procedures. The AMS 14 C data analysis routine is fairly advanced and flexible, and it can be easily optimized for different kinds of measuring processes. Technically, the system is based on a Microsoft SQL server and includes stored SQL procedures for the data analysis. Microsoft Office Access is used for the (graphical) user interface, and in addition Excel, Word and Origin are exploited for input and output of data, e.g. for plotting data during data analysis.

  20. Sedimentological time-averaging and 14C dating of marine shells

    International Nuclear Information System (INIS)

    Fujiwara, Osamu; Kamataki, Takanobu; Masuda, Fujio

    2004-01-01

    The radiocarbon dating of sediments using marine shells involves uncertainties due to the mixed ages of the shells mainly attributed to depositional processes also known as 'sedimentological time-averaging'. This stratigraphic disorder can be removed by selecting the well-preserved indigenous shells based on ecological and taphonomic criteria. These criteria on sample selection are recommended for accurate estimation of the depositional age of geologic strata from 14 C dating of marine shells

  1. Use of natural diamonds to monitor 14C AMS instrument backgrounds

    International Nuclear Information System (INIS)

    Taylor, R.E.; Southon, John

    2007-01-01

    To examine one component of the instrument-based background in University of California Keck Carbon Cycle AMS spectrometer, we have obtained measurements on a set of natural diamonds pressed into sample holders. Natural diamond samples (N = 14) from different sources within rock formations with geological ages greatly in excess of 100 Ma yielded a range of currents (∼110-250 μA 12 C - where filamentous graphite typically yields ∼150 μA 12 C - ) and apparent 14 C ages (64.9 ± 0.4 ka BP [0.00031 ± 0.00002 fm] to 80.0 ± 1.1 ka BP [0.00005 ± 0.00001 fm]). Six fragments cut from a single diamond exhibited essentially identical 14 C values - 69.3 ± 0.5 ka-70.6 ± 0.5 ka BP. The oldest 14 C age equivalents were measured on natural diamonds which exhibited the highest current yields

  2. Free flow electrophoresis separation and AMS quantitation of 14C-naphthalene-protein adducts

    International Nuclear Information System (INIS)

    Buchholz, Bruce A.; Haack, Kurt W.; Sporty, Jennifer L.; Buckpitt, Alan R.; Morin, Dexter

    2010-01-01

    Naphthalene is a volatile aromatic hydrocarbon to which humans are exposed from a variety of sources including mobile air sources and cigarette smoke. Naphthalene produces dose-(concentration)dependent injury to airway epithelial cells of murine lung which is observed at concentrations well below the current occupational exposure standard. Toxicity is dependent upon the cytochrome P450 mediated metabolic activation of the parent substrate to unstable metabolites which become bound covalently to tissue proteins. Nearly 70 proteins have been identified as forming adducts with reactive naphthalene metabolites using in vitro systems but very little work has been conducted in vivo because reasonably large amounts (100 μCi) of 14 C labeled parent compound must be administered to generate detectable adduct levels on storage phosphor screens following separation of labeled proteins by 2D gel electrophoresis. The work described here was done to provide proof of concept that protein separation by free flow electrophoresis followed by AMS detection of protein fractions containing protein bound reactive metabolites would provide adducted protein profiles in animals dosed with trace quantities of labeled naphthalene. Mice were administered 200 mg/kg naphthalene intraperitoneally at a calculated specific activity of 2 DPM/nmol (1 pCi/nmol) and respiratory epithelial tissue was obtained by lysis lavage 4 h post injection. Free flow electrophoresis (FFE) separates proteins in the liquid phase over a large pH range (2.5-11.5) using low molecular weight acids and bases to modify the pH. The apparatus separates fractions into standard 96-well plates that can be used in other protein analysis techniques. The buffers of the fractions have very high carbon content, however, and need to be dialyzed to yield buffers compatible with 14 C-AMS. We describe the processing techniques required to couple FFE to AMS for quantitation of protein adducts.

  3. Free flow electrophoresis separation and AMS quantitation of 14C-naphthalene-protein adducts

    Science.gov (United States)

    Buchholz, Bruce A.; Haack, Kurt W.; Sporty, Jennifer L.; Buckpitt, Alan R.; Morin, Dexter

    2010-04-01

    Naphthalene is a volatile aromatic hydrocarbon to which humans are exposed from a variety of sources including mobile air sources and cigarette smoke. Naphthalene produces dose-(concentration)dependent injury to airway epithelial cells of murine lung which is observed at concentrations well below the current occupational exposure standard. Toxicity is dependent upon the cytochrome P450 mediated metabolic activation of the parent substrate to unstable metabolites which become bound covalently to tissue proteins. Nearly 70 proteins have been identified as forming adducts with reactive naphthalene metabolites using in vitro systems but very little work has been conducted in vivo because reasonably large amounts (100 μCi) of 14C labeled parent compound must be administered to generate detectable adduct levels on storage phosphor screens following separation of labeled proteins by 2D gel electrophoresis. The work described here was done to provide proof of concept that protein separation by free flow electrophoresis followed by AMS detection of protein fractions containing protein bound reactive metabolites would provide adducted protein profiles in animals dosed with trace quantities of labeled naphthalene. Mice were administered 200 mg/kg naphthalene intraperitoneally at a calculated specific activity of 2 DPM/nmol (1 pCi/nmol) and respiratory epithelial tissue was obtained by lysis lavage 4 h post injection. Free flow electrophoresis (FFE) separates proteins in the liquid phase over a large pH range (2.5-11.5) using low molecular weight acids and bases to modify the pH. The apparatus separates fractions into standard 96-well plates that can be used in other protein analysis techniques. The buffers of the fractions have very high carbon content, however, and need to be dialyzed to yield buffers compatible with 14C-AMS. We describe the processing techniques required to couple FFE to AMS for quantitation of protein adducts.

  4. Free flow electrophoresis separation and AMS quantitation of {sup 14}C-naphthalene-protein adducts

    Energy Technology Data Exchange (ETDEWEB)

    Buchholz, Bruce A., E-mail: bbuchholz@llnl.go [Center for AMS, LLNL, 7000 East Avenue, Livermore, CA 94551 (United States); Haack, Kurt W.; Sporty, Jennifer L. [Center for AMS, LLNL, 7000 East Avenue, Livermore, CA 94551 (United States); Buckpitt, Alan R.; Morin, Dexter [Department of Molecular Biosciences, School of Veterinary Medicine, UC Davis, Davis, CA 95616 (United States)

    2010-04-15

    Naphthalene is a volatile aromatic hydrocarbon to which humans are exposed from a variety of sources including mobile air sources and cigarette smoke. Naphthalene produces dose-(concentration)dependent injury to airway epithelial cells of murine lung which is observed at concentrations well below the current occupational exposure standard. Toxicity is dependent upon the cytochrome P450 mediated metabolic activation of the parent substrate to unstable metabolites which become bound covalently to tissue proteins. Nearly 70 proteins have been identified as forming adducts with reactive naphthalene metabolites using in vitro systems but very little work has been conducted in vivo because reasonably large amounts (100 muCi) of {sup 14}C labeled parent compound must be administered to generate detectable adduct levels on storage phosphor screens following separation of labeled proteins by 2D gel electrophoresis. The work described here was done to provide proof of concept that protein separation by free flow electrophoresis followed by AMS detection of protein fractions containing protein bound reactive metabolites would provide adducted protein profiles in animals dosed with trace quantities of labeled naphthalene. Mice were administered 200 mg/kg naphthalene intraperitoneally at a calculated specific activity of 2 DPM/nmol (1 pCi/nmol) and respiratory epithelial tissue was obtained by lysis lavage 4 h post injection. Free flow electrophoresis (FFE) separates proteins in the liquid phase over a large pH range (2.5-11.5) using low molecular weight acids and bases to modify the pH. The apparatus separates fractions into standard 96-well plates that can be used in other protein analysis techniques. The buffers of the fractions have very high carbon content, however, and need to be dialyzed to yield buffers compatible with {sup 14}C-AMS. We describe the processing techniques required to couple FFE to AMS for quantitation of protein adducts.

  5. From 14C/12C measurements towards radiocarbon dating of ice

    NARCIS (Netherlands)

    Oerlemans, J.; Wal, R.S.W. van de; Roijen, J.J. van; Raynaud, D.; Borg, K. van der; Jong, A.F.M. de; Lipenkov, V.; Huybrechts, P.

    1994-01-01

    A dry extraction method of CO2 included in glacier ice adds a contamination equivalent to 1.8 μg modern carbon for a 35 μg C sample. This enables radiocarbon dating by accelerator mass spectrometry of 35 μg C samples to about 25 000 BP. Measured 14C/12C ratios are presented for a part of the Vostok

  6. 14C dating of early Neolithic settlement Galovo near Slavonski Brod in Northern Croatia

    International Nuclear Information System (INIS)

    Krajcar Bronic, I.; Minichreiter, K.

    2007-01-01

    In Northern Croatia, more than hundred settlements are known from the period of the Starcevo culture, the first Neolithic period in south-east (SE) Europe. Here we present the 14 C dating of nine charcoal samples from the Neolithic settlement Galovo in Slavonski Brod. According to archaeological findings, it belongs to the early phase (Linear A) of the Starcevo culture and has a special ritual-burial area separated by two wooden fences from its residential part. The vertical stratigraphy revealed two phases of the settlement construction in period 6070-5630 cal BC. In the younger phase (5380-4960 cal BC) the settlement expanded and the burial area became smaller. Combination of archaeological findings and 14 C dates thus allowed a reconstruction of the 1000-year-long existence of this settlement that existed simultaneously with the nearby settlement Zadubravlje-Duzine, dated earlier to 6000-5000 cal BC. These are the first absolute dates of the beginning of neolithization in Northern Croatia

  7. Sophistication of 14C measurement at JAEA-AMS-MUTSU. Attempt on a small quantity of sample

    International Nuclear Information System (INIS)

    Tanaka, Takayuki; Kabuto, Shoji; Kinoshita, Naoki; Yamamoto, Nobuo

    2010-01-01

    In the investigations on substance dynamics using the molecular weight and chemical fractionation, the utilization of 14 C measurement by an accelerator mass spectrometry (AMS) have started. As a result of the fractionation, sample contents required for AMS measurement have been downsized. We expect that this trend toward a small quantity of sample will be steadily accelerated in the future. As 14 C measurement by AMS established at Mutsu office require about 2 mg of sample content at present, our AMS lags behind the others in the trend. We try to downsize the needed sample content for 14 C measurement by our AMS. In this study, we modified the shape of the target-piece in which the sample is packed and which is regularly needed to radiocarbon measurement by our AMS. Moreover, we improved on the apparatus needed to pack the sample. As a result of the improvement, we revealed that it is possible to measure the 14 C using our AMS even by the amount of the sample of about 0.5 mg. (author)

  8. New and revised 14C dates for Hawaiian surface lava flows: Paleomagnetic and geomagnetic implications

    Science.gov (United States)

    Pressline, N.; Trusdell, F.A.; Gubbins, David

    2009-01-01

    Radiocarbon dates have been obtained for 30 charcoal samples corresponding to 27 surface lava flows from the Mauna Loa and Kilauea volcanoes on the Island of Hawaii. The submitted charcoal was a mixture of fresh and archived material. Preparation and analysis was undertaken at the NERC Radiocarbon Laboratory in Glasgow, Scotland, and the associated SUERC Accelerator Mass Spectrometry facility. The resulting dates range from 390 years B.P. to 12,910 years B.P. with corresponding error bars an order of magnitude smaller than previously obtained using the gas-counting method. The new and revised 14C data set can aid hazard and risk assessment on the island. The data presented here also have implications for geomagnetic modelling, which at present is limited by large dating errors. Copyright 2009 by the American Geophysical Union.

  9. A comparison of U/Th and rapid-screen 14C dates from Line Island fossil corals

    Science.gov (United States)

    Grothe, Pamela R.; Cobb, Kim M.; Bush, Shari L.; Cheng, Hai; Santos, Guaciara M.; Southon, John R.; Lawrence Edwards, R.; Deocampo, Daniel M.; Sayani, Hussein R.

    2016-03-01

    Time-consuming and expensive radiometric dating techniques limit the number of dates available to construct absolute chronologies for high-resolution paleoclimate reconstructions. A recently developed rapid-screen 14C dating technique reduces sample preparation time and per sample costs by 90%, but its accuracy has not yet been tested on shallow-water corals. In this study, we test the rapid-screen 14C dating technique on shallow-water corals by comparing 44 rapid-screen 14C dates to both high-precision 14C dates and U/Th dates from mid- to late-Holocene fossil corals collected from the central tropical Pacific (2-4°N, 157-160°W). Our results show that 42 rapid-screen 14C and U/Th dates agree within uncertainties, confirming closed-system behavior and ensuring chronological accuracy. However, two samples that grew ˜6500 years ago have calibrated 14C ages ˜1000 years younger than the corresponding U/Th ages, consistent with diagenetic alteration as indicated by the presence of 15-23% calcite. Mass balance calculations confirm that the observed dating discrepancies are consistent with 14C addition and U removal, both of which occur during diagenetic calcite recrystallization. Under the assumption that aragonite-to-calcite replacement is linear through time, we estimate the samples' true ages using the measured 14C and U/Th dates and percent calcite values. Results illustrate that the rapid-screen 14C dates of Holocene-aged fossil corals are accurate for samples with less than 2% calcite. Application of this rapid-screen 14C method to the fossil coral rubble fields from Kiritimati Island reveal significant chronological clustering of fossil coral across the landscape, with older ages farther from the water's edge.

  10. The timing of ostrich existence in Central Asia: AMS 14C age of eggshells from Mongolia and southern Siberia (a pilot study)

    International Nuclear Information System (INIS)

    Kurochkin, Evgeny N.; Kuzmin, Yaroslav V.; Antoshchenko-Olenev, Igor V.; Zabelin, Vladimir I.; Krivonogov, Sergey K.; Nohrina, Tatiana I.; Lbova, Ludmila V.; Burr, G.S.; Cruz, Richard J.

    2010-01-01

    The presence of Asiatic ostrich in Central Asia in the later Cenozoic time is well-documented; nevertheless, a few direct age determinations existed until recently. We performed AMS 14 C dating of ostrich eggshells found in Mongolia, Transbaikal, and Tuva. It shows that ostriches existed throughout the second part of Late Pleistocene, until the Late Glacial time (ca. 13,000-10,100 BP). It seems that Asiatic ostrich went extinct in Central Asia just before or even in the Holocene.

  11. Carbonate as sputter target material for rapid {sup 14}C AMS

    Energy Technology Data Exchange (ETDEWEB)

    Longworth, Brett E., E-mail: blongworth@whoi.edu [Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA (United States); Robinson, Laura F. [Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA (United States); Roberts, Mark L.; Beaupre, Steven R.; Burke, Andrea [Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA (United States); Jenkins, William J. [Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA (United States)

    2013-01-15

    This paper describes a technique for measuring the {sup 14}C content of carbonate samples by producing C{sup -} ions directly in the negative ion sputter source of an accelerator mass spectrometer (AMS) system. This direct analysis of carbonate material eliminates the time and expense of graphite preparation. Powdered carbonate is mixed with titanium powder, loaded into a target cartridge, and compressed. Beam currents for optimally-sized carbonate targets (0.09-0.15 mg C) are typically 10-20% of those produced by optimally-sized graphite targets (0.5-1 mg C). Modern (>0.8 Fm) samples run by this method have standard deviations of 0.009 Fm or less, and near-modern samples run as unknowns agree with values from traditional hydrolysis/graphite to better than 2%. Targets with as little as 0.06 mg carbonate produce useable ion currents and results, albeit with increased error and larger blank. In its current state, direct sputtering is best applied to problems where a large number of analyses with lower precision are required. These applications could include age surveys of deep-sea corals for determination of historic population dynamics, to identify samples that would benefit from high precision analysis, and for growth rate studies of organisms forming carbonate skeletons.

  12. CO2-laser decomposition method of carbonate for AMS 14C measurements

    International Nuclear Information System (INIS)

    Kitagawa, Hiroyuki

    2013-01-01

    A CO 2 laser decomposition method enabled the efficient preparation of carbonate samples for AMS 14 C measurement. Samples were loaded in a vacuum chamber and thermally decomposed using laser emission. CO 2 liberated from the carbonate was directly trapped in the cold finger trap of a small CO 2 reduction reactor and graphitized by a hydrogen gas reduction method using catalytic iron powder. The fraction modern values for 0.07–0.57 mg of carbon, obtained from 200 μm-diameter spots of IAEA-C1, varied with sample size in the range of 0.00072 ± 0.00003 to 0.00615 ± 0.00052. The contamination induced by the laser decomposition method and the following graphite handling was estimated to be 0.53 ± 0.21 μg of modern carbon, assuming a constant amount of extraneous carbon contamination. This method could also make it possible to avoid the time-consuming procedures of the conventional acid dissolution method that involves multiple complex steps for the preparation of carbonate samples.

  13. The comparison of benzene and CO2 absorption methods for radioisotope 14C dating

    International Nuclear Information System (INIS)

    Satrio and Zainal Abidin

    2007-01-01

    It had been conducted to research of age determination of carbon samples using CO 2 absorption method. This method as alternative to benzene synthesis method for radioisotope 14 C dating.The aim of the method is to support some hydrology research's especially groundwater dating using environmental radioisotope 14 C.The results which obtain by CO 2 absorption method then compared with the results of benzene synthesis method consists of background counter, standard counter, activity and age limit, age, and material cost or component. The research show that compared with benzene synthesis method, sample preparation using CO 2 absorption method is more simple and relatively low cost. The use of CO 2 absorption method can save the cost about 75 %. The different of both methods is age limit detection. The results of age limit detection when using CO 2 absorption and synthesis benzene methods are 33,310 years and 47,533 years respectively. Whereas, based on t test, the age results of both methods for the same sample are obtained relatively equal. (author)

  14. Reducing the age range of tsunami deposits by 14C dating of rip-up clasts

    Science.gov (United States)

    Ishizawa, Takashi; Goto, Kazuhisa; Yokoyama, Yusuke; Miyairi, Yosuke; Sawada, Chikako; Takada, Keita

    2018-02-01

    Erosion by tsunami waves represents an important issue when determining the age of a tsunami deposit, because the age is usually estimated using dating of sediments above and below the deposit. Dating of material within the tsunami deposit, if suitable material is obtainable, can be used to further constrain its age. Eroded sediments are sometimes incorporated within the tsunami deposits as rip-up clasts, which might therefore be used as minimum age dating material. However, the single calibrated 14C age often shows a wide age range because of fluctuations in the calibration curve. Therefore, it remains uncertain whether rip-up clast measurements are useful to constrain the depositional age of tsunami deposits, or not. In this study, we carried out high-resolution 14C dating of tsunami deposits, including rip-up clasts of peat, in Rikuzentakata, northeastern Japan, where numerous rip-up clasts were observed within a tsunami deposit. Sediments above and below the tsunami deposit and a 5 cm large rip-up clast were dated sequentially. Comparison of these dating results with the calibration curve revealed that the clast was inverted. Its age was better constrained based on the stratigraphic order, and we infer that the clast corresponds to approximately 100 years of sedimentation. The oldest age of the clast was consistent with the age of the peat immediately below the tsunami deposit, suggesting that surface sediments probably formed the rip-up clast at the time of the tsunami. Thus, the dating of the rip-up clast was useful to further constrain the depositional age of the tsunami deposit, as we narrowed the tsunami deposit age range by approximately 100 years. Results show that ignoring tsunami-related erosion might lead to overestimation of the tsunami deposit age. For this reason, an appropriate dating site, which is less affected by minor tsunami-related erosion with regards to the paleo-topography, should be explored. We therefore propose a more effective

  15. How AMS dating changed my life

    International Nuclear Information System (INIS)

    Spriggs, M.

    2001-01-01

    Accelerator mass spectrometry (AMS) radiocarbon dating was developed in the late 1970s. Remembering back to a time before AMS dating was available to archaeologists is a bit like trying to remember how we ever survived without desktop computers, email or automatic teller machines. My own particular interest in AMS dating was an inevitable offshoot from my long-established interest in chronometric hygiene, or 'getting the dates right'. In this paper I attempt to illustrate that accurate dating matters, by discussing some examples of AMS dating projects with which I have been involved over the last six years or so. In relation to these projects, AMS has given us the ability to date sites which we could not before. It has enabled us to provide more detailed stratigraphies when datable materials are rare. It has allowed us to date materials we could not date before, such as rock art pigments. It has been able to provide indications of the degree of site disturbance in the absence of other obvious forms of evidence. And it has allowed us to assess claims for the antiquity of particular material cultural types and faunal introductions. (author). 41 refs

  16. Ground water dating on the basis of the 14C content of dissolved humic and fulvic acids. Final report

    International Nuclear Information System (INIS)

    Kim, J.I.; Artinger, R.; Buckau, G.; Kardinal, C.; Geyer, S.; Wolf, M.; Halder, H.; Fritz, P.

    1995-05-01

    The groundwater dating on the basis of the 14 C content of dissolved organic carbon (DOC) is studied. Fulvic acids (FA) and humic acids (HA) are used as DOC fractions. In addition, the groundwaters are dated with the 14 C content of the dissolved inorganic carbon (DIC). The isotopic contents of 2 H, 3 H, 13 C, 15 N, 18 O, and 34 S of groundwater and humic substances are alse determined. The isolated humic substances are characterized with regard to their chemical composition as well as their molecular size and spectroscopic properties. For aquifer systems which have a neglectable content of sedimentary organic carbon (SOC), the 14 C dating of FA show plausible groundwater ages. In aquifer systems with a high SOC content, the mixing of 14 C free FA from sediment partly falsifies the 14 C groundwater age as determined by dissolved FA. Due to the high transfer of HA from sediment to groundwater, HA are less suitable for groundwater dating. The FA characterization allows the distinction between FA of sedimentary origin and FA which infiltrate with seepage water. Several starting points for a correction of the calculated 14 C ages of FA exist. The results indicate, 14 C groundwater dating with fulvic acids is a valuable expansion of groundwater dating methods. (orig.) [de

  17. Appearance and chronology of Textile ceramics in the Middle and Upper Volga region: critical comparison of conventional 14C-, AMS- and typological chronologies

    Directory of Open Access Journals (Sweden)

    Lavento Mika T.

    2015-06-01

    Full Text Available The article offers a comparison of three different methods of chronology construction – conventional 14C (radiocarbon dating, AMS (accelerator mass-spectrometry dating and the so called typological chronology – to date the textile ceramics of the Bronze – Early Iron Age in the Northern Coniferous Zone of Europe, from the Upper and Middle Volga and Kama Rivers to the Baltic region and Scandinavia. The Textile Ceramics Culture (also known as “Net”, “Pseudo-textile”, “Spun-and-speckled” is often associated with a Finnish-speaking community from the Bronze – beginning of the Iron Age. The earliest date of the Textile Ceramics sites on the Middle Oka River is presumably considered to be the 18 th century BC. Datings of the reference sites in the Middle Volga region were fixed within the 15 th – 8 th centuries BC. Comparing these data with the AMS chronology available for the materials from Finland and Estonia, the authors conclude that appearance of the Textile Ceramics was almost synchronous in the Volga and the Baltic regions, although chronology of the early tradition of the Textile Ceramics seems to be different in these areas. The results of yet a small number of AMS dates should be treated only as preliminary. However, AMS-dating seems to be the most efficient tool for further refining of the Textile Ceramics chronology over a vast territory, including in the Volga region.

  18. Chemical techniques to extract organic fractions from fossil bones for accurate 14C dating

    International Nuclear Information System (INIS)

    Minami, Masayo; Muto, Hiroo; Nakamura, Toshio

    2004-01-01

    We examined different concentrations of HCl, such as 0.4, 0.6, 0.8, 1.0 and 1.2 M, for decalcification of fossil bones and different times of 0.1 M NaOH treatment on collagens to determine the best conditions for purifying collagen through extraction of humic contaminants, and compared the alkali treatment method with the XAD-2 treatment method for several types of fossils. The yield of acid-insoluble bone fractions did not change over the range from 0.4 to 1.0 M HCl and decreased suddenly with 1.2 M HCl on decalcification, and the 14 C ages of the extracted gelatins from the five decalcified fractions were unchanged, suggesting that 14 C ages as those of the XAD-purified hydrolysates. The NaOH-treatment time should be less than several hours to avoid a loss of collagen. The fossil bones used are relatively well-preserved, but the alkali treatment could bring about a lot of loss of organic bone proteins for poorly-preserved bones. The XAD-2 treatment method is effective for accurate radiocarbon dating of fossil bones, if the XAD-2 resin is completely pre-cleaned

  19. Carbonates in leaching reactions in context of {sup 14}C dating

    Energy Technology Data Exchange (ETDEWEB)

    Michalska, Danuta, E-mail: danamich@amu.edu.pl [Institute of Geology, Faculty of Geographical and Geological Sciences, Adam Mickiewicz University, ul. Makow Polnych 16, 61-606 Poznan (Poland); Czernik, Justyna, E-mail: justyna.czernik@gmail.com [Poznań Radiocarbon Laboratory, ul. Rubież 46, 61-612 Poznań (Poland)

    2015-10-15

    Lime mortars as a mixture of binder and aggregate may contain carbon of various origins. If the mortars are made of totally burnt lime, radiocarbon dating of binder yields the real age of building construction. The presence of carbonaceous aggregate has a significant influence on the {sup 14}C measurements results and depending on the type of aggregate and fraction they may cause overaging. Another problem, especially in case of hydraulic mortars that continue to be chemically active for a very long time, is the recrystallization usually connected with rejuvenation of the results but also, depending on local geological structures, with so called reservoir effect yielding apparent ages. An attempt in separating the binder from other carbonaceous components successfully was made for samples from Israel by Nawrocka-Michalska et al. (2007). The same preparation procedure, after taking into account the petrographic composition, was used for samples coming from Poland, Nawrocka et al. (2009). To verify the procedure used previously for non-hydraulic samples determination an experimental tests on carbonaceous mortars with crushed bricks from Novae in Bulgaria were made. Additionally, to identify different carbonaceous structures and their morphology, a cathodoluminescence and scanning electron microscope with electron dispersive spectrometer were applied. The crushed bricks and brick dust used in mortars production process have been interpreted as an alternative use to other pozzolanic materials. The reaction between lime and pozzolanic additives take place easily and affects the rate and course of carbonates decomposition in orthophosphric acid, during the samples pretreatment for dating. The composition of the Bulgarian samples together with influence of climate conditions on mortar carbonates do not allow for making straightforward conclusions in chronology context, but gives some new guidelines in terms of hydraulic mortars application for dating. This work has mainly

  20. Carbonates in leaching reactions in context of "1"4C dating

    International Nuclear Information System (INIS)

    Michalska, Danuta; Czernik, Justyna

    2015-01-01

    Lime mortars as a mixture of binder and aggregate may contain carbon of various origins. If the mortars are made of totally burnt lime, radiocarbon dating of binder yields the real age of building construction. The presence of carbonaceous aggregate has a significant influence on the "1"4C measurements results and depending on the type of aggregate and fraction they may cause overaging. Another problem, especially in case of hydraulic mortars that continue to be chemically active for a very long time, is the recrystallization usually connected with rejuvenation of the results but also, depending on local geological structures, with so called reservoir effect yielding apparent ages. An attempt in separating the binder from other carbonaceous components successfully was made for samples from Israel by Nawrocka-Michalska et al. (2007). The same preparation procedure, after taking into account the petrographic composition, was used for samples coming from Poland, Nawrocka et al. (2009). To verify the procedure used previously for non-hydraulic samples determination an experimental tests on carbonaceous mortars with crushed bricks from Novae in Bulgaria were made. Additionally, to identify different carbonaceous structures and their morphology, a cathodoluminescence and scanning electron microscope with electron dispersive spectrometer were applied. The crushed bricks and brick dust used in mortars production process have been interpreted as an alternative use to other pozzolanic materials. The reaction between lime and pozzolanic additives take place easily and affects the rate and course of carbonates decomposition in orthophosphric acid, during the samples pretreatment for dating. The composition of the Bulgarian samples together with influence of climate conditions on mortar carbonates do not allow for making straightforward conclusions in chronology context, but gives some new guidelines in terms of hydraulic mortars application for dating. This work has mainly

  1. A new procedure for extraction of collagen from modern and archaeological bones for {sup 14}C dating

    Energy Technology Data Exchange (ETDEWEB)

    Maspero, F. [CUDaM, University of Milano Bicocca, Milano (Italy); Sala, S.; Papagni, A. [University of Milano Bicocca, Materials Science Department, Milano (Italy); Fedi, M.E. [INFN sezione di Firenze, Sesto Fiorentino (Firenze) (Italy); Martini, M. [CUDaM, University of Milano Bicocca, Milano (Italy); University of Milano Bicocca, Materials Science Department, Milano (Italy); INFN sezione di Milano Bicocca, Milano (Italy)

    2011-10-15

    Bones are potentially the best age indicators in a stratigraphic study, because they are closely related to the layer in which they are found. Collagen is the most suitable fraction and is the material normally used in radiocarbon dating. Bone contaminants can strongly alter the carbon isotopic fraction values of the samples, so chemical pretreatment for {sup 14} C dating by accelerator mass spectrometry (AMS) is essential. The most widespread method for collagen extraction is based on the Longin procedure, which consists in HCl demineralization to dissolve the inorganic phase of the samples, followed by dissolution of collagen in a weak acid solution. In this work the possible side effects of this procedure on a modern bone are presented; the extracted collagen was analyzed by ATR-IR spectroscopy. An alternative procedure, based on use of HF instead of HCl, to minimize unwanted degradation of the organic fraction, is also given. A study by ATR-IR spectroscopic analysis of collagen collected after different demineralization times and with different acid volumes, and a study of an archaeological sample, are also presented. (orig.)

  2. Application of /sup 14/C-dating to sedimentary geology and climatology: Sea-level and climate change during the Holocene

    Energy Technology Data Exchange (ETDEWEB)

    Nakai, Nobuyuki; Ohishi, Shyoji; Kuriyama, Toyoko; Nakamura, Toshio

    1987-11-01

    AMS /sup 14/C dating of small sized fossil shells, wood chips and sedimentary humic matter has been applied to the investigation of paleoclimatic and sea-level changes in the Holocene, using three estuarine and brackish lake sediment cores, drilled in Kawasaki city and Lake Hamanako, Japan. Precise and detailed ages at differing depths clarified large transitions of Holocene sedimentation rates, of two orders of magnitude. The vertical variation in delta/sup 13/C and C/N results for sedimentary organic matter, combined with AMS /sup 14/C ages, established continous climatic and sea-level fluctuation patterns through time and indicated the existence of neoglaciation coincident with the marine regression at 7500 to 7000 yr BP.

  3. Progress in AMS measurement of "1"2"9I and "1"4C at CIAE

    International Nuclear Information System (INIS)

    Yang Xuran; Dong, K.J.; Shan, J.; He Ming; Xie, L.B.

    2013-01-01

    Twenty-four years have passed since the AMS was built at China Institute of Atomic Energy (CIAE) in 1989. We have measured "2"3"6U, "1"8"2Hf, "5"9Ni and other elements. Recently, the routine method of measuring the "1"2"9I concentration in air particle samples using AMS have been set up due to it has great advantages to measure long-lived radioisotopes. For the applications, "1"2"9I could be used for monitoring nuclear environment. "1"2"9I was collected in air particle samples after the accident of Fukushima nuclear power plant and measured at the China Institute of Atomic Energy (CIAE) by using AMS, the result show that "1"2"9I derived from FNPP accident had been arrived in Beijing early on March 26th and "1"2"9I concentration had been greatly increased relative to March 20th. On the other hand, a new system to measure "1"4C of AMS will be designed for the application in bio-medical science: urea breath test (UBT). UBT has been carried out widely by using carbon isotope of "1"3C and "1"4C, respectively, in the world. They are two tracers with different measurement methods but applied by the same principle. Optimizing UBT methods with using "1"4C is the priori for the diagnosis of helicobacter pylori in the future. (author)

  4. Quantity of dates trumps quality of dates for dense Bayesian radiocarbon sediment chronologies - Gas ion source 14C dating instructed by simultaneous Bayesian accumulation rate modeling

    Science.gov (United States)

    Rosenheim, B. E.; Firesinger, D.; Roberts, M. L.; Burton, J. R.; Khan, N.; Moyer, R. P.

    2016-12-01

    Radiocarbon (14C) sediment core chronologies benefit from a high density of dates, even when precision of individual dates is sacrificed. This is demonstrated by a combined approach of rapid 14C analysis of CO2 gas generated from carbonates and organic material coupled with Bayesian statistical modeling. Analysis of 14C is facilitated by the gas ion source on the Continuous Flow Accelerator Mass Spectrometry (CFAMS) system at the Woods Hole Oceanographic Institution's National Ocean Sciences Accelerator Mass Spectrometry facility. This instrument is capable of producing a 14C determination of +/- 100 14C y precision every 4-5 minutes, with limited sample handling (dissolution of carbonates and/or combustion of organic carbon in evacuated containers). Rapid analysis allows over-preparation of samples to include replicates at each depth and/or comparison of different sample types at particular depths in a sediment or peat core. Analysis priority is given to depths that have the least chronologic precision as determined by Bayesian modeling of the chronology of calibrated ages. Use of such a statistical approach to determine the order in which samples are run ensures that the chronology constantly improves so long as material is available for the analysis of chronologic weak points. Ultimately, accuracy of the chronology is determined by the material that is actually being dated, and our combined approach allows testing of different constituents of the organic carbon pool and the carbonate minerals within a core. We will present preliminary results from a deep-sea sediment core abundant in deep-sea foraminifera as well as coastal wetland peat cores to demonstrate statistical improvements in sediment- and peat-core chronologies obtained by increasing the quantity and decreasing the quality of individual dates.

  5. Local variations in {sup 14}C - How is bomb-pulse dating of human tissues and cells affected?

    Energy Technology Data Exchange (ETDEWEB)

    Stenstroem, Kristina, E-mail: Kristina.Stenstrom@nuclear.lu.s [Lund University, Department of Physics, Division of Nuclear Physics, Box 118, SE-221 00 Lund (Sweden); Skog, Goeran [Lund University, GeoBiosphere Science Centre, Geocentrum II, Soelvegatan 12, SE-223 672 Lund (Sweden); Nilsson, Carl Magnus [Lund University, Department of Physics, Division of Nuclear Physics, Box 118, SE-221 00 Lund (Sweden); Lund University, Department of Medical Radiation Physics, Malmoe University Hospital, SE-205 02 Malmoe (Sweden); Hellborg, Ragnar [Lund University, Department of Physics, Division of Nuclear Physics, Box 118, SE-221 00 Lund (Sweden); Svegborn, Sigrid Leide [Lund University, Department of Medical Radiation Physics, Malmoe University Hospital, SE-205 02 Malmoe (Sweden); Georgiadou, Elisavet [Lund University, Department of Physics, Division of Nuclear Physics, Box 118, SE-221 00 Lund (Sweden); Mattsson, Soeren [Lund University, Department of Medical Radiation Physics, Malmoe University Hospital, SE-205 02 Malmoe (Sweden)

    2010-04-15

    Atmospheric nuclear weapons testing in the late 1950s and early 1960s almost doubled the amount of {sup 14}C in the atmosphere. The resulting {sup 14}C 'bomb-pulse' has been shown to provide useful age information in e.g. forensic and environmental sciences, biology and the geosciences. The technique is also currently being used for retrospective cell dating in man, in order to provide insight into the rate of formation of new cells in the human body. Bomb-pulse dating relies on precise measurements of the declining {sup 14}C concentration in atmospheric CO{sub 2} collected at clean-air sites. However, it is not always recognized that the calculations can be complicated in some cases by significant local variations in the specific activity of {sup 14}C in carbon in the air and foodstuff. This paper presents investigations of local {sup 14}C variations in the vicinities of nuclear installations and laboratories using {sup 14}C. Levels of {sup 14}C in workers using this radioisotope are also discussed.

  6. AMS Radiocarbon Dating at Notre Dame

    Science.gov (United States)

    Howard, Sean

    2014-09-01

    Current development of a local radiocarbon dating method using Accelerator Mass Spectrometry (AMS) at the University of Notre Dame seeks to provide sensitive, reproducible, and accurate measurements for future interdisciplinary projects. While AMS has been the premier radiocarbon dating method for a few decades, repurposing Notre Dame's FN Tandem accelerator for radiocarbon dating has provided many unique challenges. Experiments have shown radiocarbon dating possible and reproducible using the FN Tandem accelerator, found optimal settings for said accelerator, and established sensitivity limits comparable to dedicated radiocarbon dating facilities. In addition, there is ongoing work to create a local chemistry lab to convert organic artifacts into graphite samples to be dated locally. Once the chemistry side has been completed, several artifacts from the IAEA's radiocarbon intercomparison have been procured. Dating these previously studied artifacts will provide an additional measure on the accuracy and repeatability of both the accelerator and chemical treatment. Provided that these IAEA artifacts are dated successfully, exciting projects will ensue, such as the authentication of artwork and dating of anthropological samples.

  7. Dietary reconstruction and reservoir correction of 14C dates on bones from pagan and early Christian graves in Iceland

    DEFF Research Database (Denmark)

    Sveinbjörnsdóttir, Árný E; Heinemeier, Jan; Arneborg, Jette

    2010-01-01

    between the excavation site and the seashore. We have radiocarbon dated 47 of these skeletons and used the carbon isotopic composition (?13C) to estimate and correct for the marine reservoir effect (the 14C difference between terrestrial and mixed marine organisms). The reservoir-corrected ages lie...... in the range of AD 780?1270 (68.2% probability). Reservoir age corrections were checked by comparing 14C dates of a horse (terrestrial diet), a dog (highly marine diet), and a human (mixed diet) from the same burial. The range in measured marine protein percentage in individual diet is from about 10% up to 55...... in AD 1211. Using our dietary reconstruction, his bones were about 17% marine, which is within the range of human skeletons from the same area, and the reservoir-corrected calibrated 14C age of the skeleton is in accord with the historical date....

  8. 14C sample preparation for AMS microdosing studies at Lund University using online combustion and septa-sealed vials

    Science.gov (United States)

    Sydoff, Marie; Stenström, Kristina

    2010-04-01

    The Department of Physics at Lund University is participating in a European Union project called EUMAPP (European Union Microdose AMS Partnership Programme), in which sample preparation and accelerator mass spectrometry (AMS) measurements of biological samples from microdosing studies have been made. This paper describes a simplified method of converting biological samples to solid graphite for 14C analysis with AMS. The method is based on online combustion of the samples, and reduction of CO 2 in septa-sealed vials. The septa-sealed vials and disposable materials are used to eliminate sample cross-contamination. Measurements of ANU and Ox I standards show deviations of 2% and 3%, respectively, relative to reference values. This level of accuracy is sufficient for biological samples from microdosing studies. Since the method has very few handling steps from sample to graphite, the risk of failure during the sample preparation process is minimized, making the method easy to use in routine preparation of samples.

  9. {sup 14}C sample preparation for AMS microdosing studies at Lund University using online combustion and septa-sealed vials

    Energy Technology Data Exchange (ETDEWEB)

    Sydoff, Marie, E-mail: marie.sydoff@med.lu.s [Department of Clinical Sciences, Medical Radiation Physics, Malmo University Hospital, SE-205 02 Malmoe (Sweden); Lund University, Department of Physics, Division of Nuclear Physics, P.O. Box 118, SE-221 00 Lund (Sweden); Stenstroem, Kristina [Lund University, Department of Physics, Division of Nuclear Physics, P.O. Box 118, SE-221 00 Lund (Sweden)

    2010-04-15

    The Department of Physics at Lund University is participating in a European Union project called EUMAPP (European Union Microdose AMS Partnership Programme), in which sample preparation and accelerator mass spectrometry (AMS) measurements of biological samples from microdosing studies have been made. This paper describes a simplified method of converting biological samples to solid graphite for {sup 14}C analysis with AMS. The method is based on online combustion of the samples, and reduction of CO{sub 2} in septa-sealed vials. The septa-sealed vials and disposable materials are used to eliminate sample cross-contamination. Measurements of ANU and Ox I standards show deviations of 2% and 3%, respectively, relative to reference values. This level of accuracy is sufficient for biological samples from microdosing studies. Since the method has very few handling steps from sample to graphite, the risk of failure during the sample preparation process is minimized, making the method easy to use in routine preparation of samples.

  10. 14C sample preparation for AMS microdosing studies at Lund University using online combustion and septa-sealed vials

    International Nuclear Information System (INIS)

    Sydoff, Marie; Stenstroem, Kristina

    2010-01-01

    The Department of Physics at Lund University is participating in a European Union project called EUMAPP (European Union Microdose AMS Partnership Programme), in which sample preparation and accelerator mass spectrometry (AMS) measurements of biological samples from microdosing studies have been made. This paper describes a simplified method of converting biological samples to solid graphite for 14 C analysis with AMS. The method is based on online combustion of the samples, and reduction of CO 2 in septa-sealed vials. The septa-sealed vials and disposable materials are used to eliminate sample cross-contamination. Measurements of ANU and Ox I standards show deviations of 2% and 3%, respectively, relative to reference values. This level of accuracy is sufficient for biological samples from microdosing studies. Since the method has very few handling steps from sample to graphite, the risk of failure during the sample preparation process is minimized, making the method easy to use in routine preparation of samples.

  11. Accessing the application of in situ cosmogenic 14C to surface exposure dating of amorphous SiO2

    Science.gov (United States)

    Cesta, J. M.; Goehring, B. M.; Ward, D. J.

    2017-12-01

    We assess the feasibility and utility of in situ cosmogenic 14C as a geochronometer for landforms composed of amorphous SiO2 through the comparison of 14C surface exposure ages to independently determined eruption ages on Obsidian Dome, California. Landforms composed of amorphous SiO2 phases are difficult to date by conventional cosmogenic nuclide methods due to several complications that may arise (e.g., inability to remove meteoric contamination). The onset of an increased understanding of production rates and analytical measurement of in situ 14C in SiO2 provides an opportunity to address this limitation. Obsidian Dome is a 600-year-old phreatomagmatic dome of the Mono-Inyo Craters located in Inyo County, California, and consists of vesicular pumice, obsidian, and rhyolite. Exposure ages from eight obsidian and banded pumice and obsidian surface samples range from 3947 ± 678 to 914 ± 134 years, all significantly older than the accepted radiocarbon age of 650-550 years. δ13C values for the samples range between +2.65‰ and +1.34‰ and show a negative correlation with CO2 yield. The `too old' exposure ages coupled with this negative correlation between δ13C and CO2 yield suggests the incorporation of an atmospheric component of 14C. Measurement of 14C concentrations in shielded, subsurface samples will assist in isolating the atmospheric 14C component and aid in correcting the surface exposure ages.

  12. High temperature vacuum furnace for the preparation of graphite targets for 14C dating by tandem accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Lowe, D.C.; Bristow, P.; Judd, W.J.

    1985-02-01

    A simple and reliable furnace design capable of producing temperatures of up to 2800 deg. C is presented. The furnace has been specifically designed for the rapid and reliable production of graphite targets for 14 C dating purposes but may be used in a variety of applications requiring high temperatures under vacuum conditions

  13. From scrolls to Picasso: AMS radiocarbon dating applied to textiles, art works and artifacts

    Energy Technology Data Exchange (ETDEWEB)

    Jull, A.J.T.; Donahue, D.J.; Beck, J.W.; Burr, G.S.; O`Malley, J.; Hewitt, L.; Biddulph, D.; Hatheway, A.L.; Lange, T.E.; Toolin, J. [Arizona Univ., Tucson, AZ (United States). NSF Arizona Accelerator Mass Spectrometry Facility

    1997-12-31

    Full text: The use of accelerator mass spectrometry (AMS) for radiocarbon dating allows us to use very small samples of carbon, <1 mg. This has opened a vast array of applications of radiocarbon dating which were difficult to do before AMS, due to sample size limitations of decay counting. We have successfully applied AMS {sup 14}C to dating of many types of textiles, including silks and linens, art works, documents and artifacts fabricated from wood, parchment, ivory and bone. For many of these types of samples, the results are often important in questions of the authenticity of these works of art and artifacts. This has encompassed a wide range of art works ranging from the Dead Sea Scrolls, the Shroud of Turin and the Chinese silk trade to the works of Raphael, Rembrandt and Picasso. Most recently, we have also dated the Vinland Map, a controversial document which shows the eastern coast of North America apparently using information from Viking voyages. An important issue in such studies is also the radiocarbon calibration curve. For some periods, most notably 1700-1950 AD we know that several changes in the {sup 14}C composition of the atmosphere make it almost impossible to date a sample during this period more precisely than the entire range. However, before this period, we have successfully dated materials to high precision. We have also studied the use of the period l900-1950 AD for {sup 14}C measurements and will present some examples where the rapid decline in {Delta} {sup 14}C can be used to date art works. The period after 1950AD also allows us to identify works fabricated from recent materials using the `spike` in {sup 14}C due to atmospheric nuclear testing. This bomb {sup 14}C has also been successfully used to identify originals from copies of works purporting to be the originals. We will discuss some artifacts, art works and forgeries, where {sup 14}C can resolve problems of authenticity (authors).

  14. 14C-AMS as a tool for the investigation of mercury deposition at a remote Amazon location

    International Nuclear Information System (INIS)

    Barbosa, J.A.; Cordeiro, R.C.; Silva, E.V.; Turcq, B.; Gomes, P.R.S.; Santos, G.M.; Sifedinne, A.; Albuquerque, A.L.S.; Lacerda, L.D.; Hausladen, P.A.; Tims, S.G.; Levchenko, V.A.; Fifield, L.K.

    2004-01-01

    We present results of the atmospheric mercury deposition rate in the Amazon region during the last 43 000 years. Lake sediment samples were collected from the Lagoa da Pata, a small and remote lake in northern Brazilian Amazon. The samples were divided in sub-samples, for C, Hg, N and 14 C-AMS analyses. Three main paleoclimatic events could be identified. The mercury accumulation rates were found to be larger during the periods of the Holocene and Pleistocene associated with high temperatures and frequency of forest fires

  15. Status report on sample preparation facilities for {sup 14}C analysis at the new CologneAMS center

    Energy Technology Data Exchange (ETDEWEB)

    Rethemeyer, J., E-mail: janet.rethemeyer@uni-koeln.de [Institute of Geology and Mineralogy, University of Cologne, 50674 Cologne (Germany); Fueloep, R.-H.; Hoefle, S. [Institute of Geology and Mineralogy, University of Cologne, 50674 Cologne (Germany); Wacker, L. [Ion Beam Physics, ETH Zuerich, 8093 Zuerich (Switzerland); Heinze, S. [Institute of Nuclear Physics, University of Cologne, 50674 Cologne (Germany); Hajdas, I. [Ion Beam Physics, ETH Zuerich, 8093 Zuerich (Switzerland); Patt, U.; Koenig, S.; Stapper, B. [Institute of Geology and Mineralogy, University of Cologne, 50674 Cologne (Germany); Dewald, A. [Institute of Nuclear Physics, University of Cologne, 50674 Cologne (Germany)

    2013-01-15

    The new AMS facility at University of Cologne (CologneAMS), Germany, was established in 2010 with the delivery of the HVE 6 MV Tandetron AMS, which will be used for {sup 14}C, {sup 26}Al, {sup 36}Cl, {sup 41}Ca, {sup 129}I, {sup 239}U and {sup 244}Pu analyses. Parallel to the AMS installation the radiocarbon group has started to set up and test sample preparation methods and instruments for different materials. We present first results of reference and standard materials that have been processed and graphitized in our lab and measured at the ETH and CologneAMS facilities. The graphitization blank and its influence on small samples sizes processed with an automated graphitization system have been determined. Work on isolation of individual organic compounds with a preparative gas chromatography system has been started. The focus of our future work will be on reducing process blank levels and sample sizes as well as on the application of compound-specific radiocarbon analyses in (paleo-) environmental research.

  16. Status report on sample preparation facilities for 14C analysis at the new CologneAMS center

    International Nuclear Information System (INIS)

    Rethemeyer, J.; Fülöp, R.-H.; Höfle, S.; Wacker, L.; Heinze, S.; Hajdas, I.; Patt, U.; König, S.; Stapper, B.; Dewald, A.

    2013-01-01

    The new AMS facility at University of Cologne (CologneAMS), Germany, was established in 2010 with the delivery of the HVE 6 MV Tandetron AMS, which will be used for 14 C, 26 Al, 36 Cl, 41 Ca, 129 I, 239 U and 244 Pu analyses. Parallel to the AMS installation the radiocarbon group has started to set up and test sample preparation methods and instruments for different materials. We present first results of reference and standard materials that have been processed and graphitized in our lab and measured at the ETH and CologneAMS facilities. The graphitization blank and its influence on small samples sizes processed with an automated graphitization system have been determined. Work on isolation of individual organic compounds with a preparative gas chromatography system has been started. The focus of our future work will be on reducing process blank levels and sample sizes as well as on the application of compound-specific radiocarbon analyses in (paleo-) environmental research.

  17. Analysis of 14C and 13C in teeth provides precise birth dating and clues to geographical origin.

    Science.gov (United States)

    Alkass, K; Buchholz, B A; Druid, H; Spalding, K L

    2011-06-15

    The identification of human bodies in situations when there are no clues as to the person's identity from circumstantial data, poses a difficult problem to the investigators. The determination of age and sex of the body can be crucial in order to limit the search to individuals that are a possible match. We analyzed the proportion of bomb pulse derived carbon-14 ((14)C) incorporated in the enamel of teeth from individuals from different geographical locations. The 'bomb pulse' refers to a significant increase in (14)C levels in the atmosphere caused by above ground test detonations of nuclear weapons during the cold war (1955-1963). By comparing (14)C levels in enamel with (14)C atmospheric levels systematically recorded over time, high precision birth dating of modern biological material is possible. Above ground nuclear bomb testing was largely restricted to a couple of locations in the northern hemisphere, producing differences in atmospheric (14)C levels at various geographical regions, particularly in the early phase. Therefore, we examined the precision of (14)C birth dating of enamel as a function of time of formation and geographical location. We also investigated the use of the stable isotope (13)C as an indicator of geographical origin of an individual. Dental enamel was isolated from 95 teeth extracted from 84 individuals to study the precision of the (14)C method along the bomb spike. For teeth formed before 1955 (N=17), all but one tooth showed negative Δ(14)C values. Analysis of enamel from teeth formed during the rising part of the bomb-spike (1955-1963, N=12) and after the peak (>1963, N=66) resulted in an average absolute date of birth estimation error of 1.9±1.4 and 1.3±1.0 years, respectively. Geographical location of an individual had no adverse effect on the precision of year of birth estimation using radiocarbon dating. In 46 teeth, measurement of (13)C was also performed. Scandinavian teeth showed a substantially greater depression in

  18. 14C dating and stable carbon isotopes of soil organic matter in the Southeastern region of Sao Paulo State

    International Nuclear Information System (INIS)

    Mofatto, Milene; Pessenda, Luiz Carlos Ruiz; Bendassoli, Jose Albertino; Leite, Acacio Zuniga; Oliveira, Paulo de Oliveira; Garcia, Ricardo Jose Francischetti

    2005-01-01

    The objective of this research is to characterize the isotopic composition ( 13 C, 14 C) of soil organic matter (SOM) in the Parque Estadual da Serra do Mar-Nucleo Curucutu, Sao Paulo state, Southeastern Brazil. The isotopic composition (δ 13 C) of SOM will be used as an indicator of vegetation types from the local ecosystems and 14 C dating (humin fraction) used to determine the chronology. The results from SOM indicated vegetation changes in the last 10,000 years, where, a less dense vegetation occurred in the past, with C 3 plant predominant and/or a mixture of C 3 and C 4 . (author)

  19. The remarkable metrological history of 14C dating: from ancient Egyptian artifacts to particles of soot and grains of pollen

    International Nuclear Information System (INIS)

    Currie, L.A.

    2003-01-01

    Radiocarbon dating would not have been possible if 14 C had not had the 'wrong' half-life - a fact that delayed its discovery. Following the discovery of this 5730 year radionuclide in laboratory experiments by Ruben and Kamen, it became clear to W. F. Libby that 14 C should exist in nature, and that it could serve as a quantitative means for dating artifacts and events marking the history of civilization. The search for natural radiocarbon was a metrological challenge; the level in the living biosphere (ca. 230 Bq/kg) lay far beyond the then current state of the measurement art. This article traces the metrological history of radiocarbon, from the initial breakthrough devised by Libby, to minor (evolutionary) and major (revolutionary) advances that have brought 14 C measurement from a crude, bulk (8 g carbon) dating tool, to a refined probe for dating tiny amounts of precious artifacts, and for 'molecular dating' at the 10 μg to 100 mg level. The metrological advances led to opportunities and surprises, such as the non-monotonic dendrochronological calibration curve and the 'bomb effect', that spawned new multidisciplinary areas of application, ranging from cosmic ray physics to oceanography to the reconstruction of environmental history. (author)

  20. Two years since SSAMS: Status of {sup 14}C AMS at CAIS

    Energy Technology Data Exchange (ETDEWEB)

    Ravi Prasad, G.V.; Cherkinsky, Alexander; Culp, Randy A.; Dvoracek, Doug K.

    2015-10-15

    The NEC 250 kV single stage AMS accelerator (SSAMS) was installed two years ago at the Center for Applied Isotope Studies (CAIS), University of Georgia. The accelerator is primarily being used for radiocarbon measurements to test the authenticity of natural and bio-based samples while all other samples such as geological, atmospheric, marine and archaeological. are run on the 500 kV, NEC 1.5SDH-1 model tandem accelerator, which has been operating since 2001. The data obtained over a six months period for OXI, OXII, ANU sucrose and FIRI-D are discussed. The mean value of ANU sucrose observed to be slightly lower than the consensus value. The processed blanks on SSAMS produce lower apparent age compared to the tandem accelerator as expected.

  1. The remarkable metrological history of 14C dating: From ancient Egyptian artifacts to particles of soot and grains of pollen

    Science.gov (United States)

    Currie, L. A.

    2003-01-01

    Radiocarbon dating would not have been possible if 14C had not had the “wrong” half-life—a fact that delayed its discovery [1]. Following the discovery of this 5730 year radionuclide in laboratory experiments by Ruben and Kamen, it became clear to W. F. Libby that 14C should exist in nature, and that it could serve as a quantitative means for dating artifacts and events marking the history of civilization. The search for natural radiocarbon was a metrological challenge; the level in the living biosphere [ca. 230 Bq/kg] lay far beyond the then current state of the measurement art. This article traces the metrological history of radiocarbon, from the initial breakthrough devised by Libby, to minor (evolutionary) and major (revolutionary) advances that have brought 14C measurement from a crude, bulk [8 g carbon] dating tool, to a refined probe for dating tiny amounts of precious artifacts, and for “molecular dating” at the 10 μg to 100 μg level. The metrological advances led to opportunities and surprises, such as the non-monotonic dendrochronological calibration curve and the “bomb effect,” that spawned new multidisciplinary areas of application, ranging from cosmic ray physics to oceanography to the reconstruction of environmental history.

  2. Accelerator mass spectrometry 14C dating of lime mortars: Methodological aspects and field study applications at CIRCE (Italy)

    Science.gov (United States)

    Marzaioli, Fabio; Nonni, Sara; Passariello, Isabella; Capano, Manuela; Ricci, Paola; Lubritto, Carmine; De Cesare, Nicola; Eramo, Giacomo; Quirós Castillo, Juan Antonio; Terrasi, Filippo

    2013-01-01

    Centre for Isotopic Research on Cultural and Environmental heritage (CIRCE) has, recently, obtained some promising results in testing the feasibility of mortar radiocarbon dating by means of an ad hoc developed purification procedure (CryoSoniC: Cryobraking, Sonication, Centrifugation) applied to a series of laboratory mortars. Observed results encouraged CryoSoniC accuracy evaluation on genuine mortars sampled from archeological sites of known or independently constrained age (i.e., other 14C dates on different materials). In this study, some 14C measurements performed on genuine mortars will be discussed and compared with independently estimated (i.e., radiocarbon/archaeometrical dating) absolute chronologies of two Spanish sites. Observed results confirm the agreement of the CryoSoniC mortar dates with the archaeological expectations for both examined cases. Several authors reported the possibility of obtaining accurate radiocarbon dates of mortar matrices by analyzing lime lumps: binder-related particles of different sizes exclusively composed of calcium carbonate. In this paper, preliminary data for the absolute chronology reconstruction of the Basilica of the cemetery complex of Ponte della Lama (Canosa di Puglia, Italy) based on lime lumps will also be discussed. Dating accuracy will be quantified by comparing 14C data on mortar lime lumps from a funerary inscription of known age found near the Basilica, in the same study site. For this site, a comparison between absolute chronologies performed by bulk and CryoSoniC purified lime lumps, and charcoal incased in mortars (when found) will also be discussed. Observed results for this site provide evidence of how bulk lime lump dating may introduce systematic overestimations of the analyzed sample while CryoSoniC purification allows accurate dating.

  3. Accelerator mass spectrometry {sup 14}C dating of lime mortars: Methodological aspects and field study applications at CIRCE (Italy)

    Energy Technology Data Exchange (ETDEWEB)

    Marzaioli, Fabio, E-mail: fabio.marzaioli@unina2.it [CIRCE, INNOVA and Seconda Universita degli Studi di Napoli, Dipartimento di Scienze Ambientali, Caserta (Italy); Nonni, Sara, E-mail: sara.nonni@uniroma1.it [Dipartimento di Scienze della Terra, ' Sapienza' Universita di Roma (Italy); Passariello, Isabella, E-mail: isabella.passariello@unina2.it [CIRCE, INNOVA and Seconda Universita degli Studi di Napoli, Dipartimento di Scienze Ambientali, Caserta (Italy); Capano, Manuela, E-mail: manuela.capano@unina2.it [CIRCE, INNOVA and Dipartimento di Studio delle Componenti Culturali del Territorio, Seconda Universita degli Studi di Napoli, Santa Maria Capua Vetere, Caserta (Italy); Ricci, Paola, E-mail: paola.ricci@unina2.it [CIRCE, INNOVA and Seconda Universita degli Studi di Napoli, Dipartimento di Scienze Ambientali, Caserta (Italy); Lubritto, Carmine, E-mail: carmine.lubritto@unina2.it [CIRCE, INNOVA and Seconda Universita degli Studi di Napoli, Dipartimento di Scienze Ambientali, Caserta (Italy); De Cesare, Nicola, E-mail: nicola.decesare@unina2.it [CIRCE, INNOVA and Seconda Universita degli Studi di Napoli, Dipartimento di Scienze della Vita, Caserta (Italy); Eramo, Giacomo, E-mail: giacomo.eramo@uniba.it [Dipartimento di Scienze della Terra e Geoambientali, Universita degli Studi di Bari ' Aldo Moro' , Bari (Italy); Quiros Castillo, Juan Antonio, E-mail: quiros.castillo@ehu.es [Universidad del Pais Vasco-Euskal Herriko Unibertsitatea, Dipartimento di Geografia, Prehistoria y Arqueologia, Vitoria-Gasteiz (Spain); and others

    2013-01-15

    Centre for Isotopic Research on Cultural and Environmental heritage (CIRCE) has, recently, obtained some promising results in testing the feasibility of mortar radiocarbon dating by means of an ad hoc developed purification procedure (CryoSoniC: Cryobraking, Sonication, Centrifugation) applied to a series of laboratory mortars. Observed results encouraged CryoSoniC accuracy evaluation on genuine mortars sampled from archeological sites of known or independently constrained age (i.e., other {sup 14}C dates on different materials). In this study, some {sup 14}C measurements performed on genuine mortars will be discussed and compared with independently estimated (i.e., radiocarbon/archaeometrical dating) absolute chronologies of two Spanish sites. Observed results confirm the agreement of the CryoSoniC mortar dates with the archaeological expectations for both examined cases. Several authors reported the possibility of obtaining accurate radiocarbon dates of mortar matrices by analyzing lime lumps: binder-related particles of different sizes exclusively composed of calcium carbonate. In this paper, preliminary data for the absolute chronology reconstruction of the Basilica of the cemetery complex of Ponte della Lama (Canosa di Puglia, Italy) based on lime lumps will also be discussed. Dating accuracy will be quantified by comparing {sup 14}C data on mortar lime lumps from a funerary inscription of known age found near the Basilica, in the same study site. For this site, a comparison between absolute chronologies performed by bulk and CryoSoniC purified lime lumps, and charcoal incased in mortars (when found) will also be discussed. Observed results for this site provide evidence of how bulk lime lump dating may introduce systematic overestimations of the analyzed sample while CryoSoniC purification allows accurate dating.

  4. 14C chronology of the oldest Scandinavian church in use. An AMS/PIXE study of lime lump carbonate in the mortar

    International Nuclear Information System (INIS)

    Lindroos, Alf; Ranta, Heikki; 14C Dating Laboratory, Department of Physics and Astronomy, University of Aarhus (Denmark))" data-affiliation=" (AMS 14C Dating Laboratory, Department of Physics and Astronomy, University of Aarhus (Denmark))" >Heinemeier, Jan; Lill, Jan-Olof

    2014-01-01

    Mortar dating was applied to newly revealed, original mortar in the church of Dalby in Scania, southern Sweden which is considered to be the oldest still standing church in Scandinavia. Small white lime lumps were sampled by chipping from the supporting pillars in the interior of the church. Special emphasis was in sampling lime lumps because the church is situated in the Scania limestone area and aggregate limestone contamination was anticipated in the bulk mortars. Earlier studies have, however, shown that lime lumps do not contain aggregate material but only possible limestone rests from incomplete calcination. The sampled material was prepared for radiocarbon AMS dating. The carbonate in the lime lumps was hydrolyzed according to the sequential leaching technique developed for the Århus 14 C laboratory in Denmark. Prior to the hydrolysis the lime lumps were examined for dead-carbon contamination using a stereo microscope and cathodoluminescence. The lime lumps displayed heterogeneous carbonate luminescence. This is, however, common and it was not considered a problem because carbonate growth in changing pH/Eh conditions often leads to changing luminescence colors. Two lumps had little dead carbon contamination and an early second millennium 14 C signature. One lump, however, seemed to be heavily contaminated with dead carbon. Since the sample passed the microscopic screening, the leftovers of the lump was subjected to PIXE analysis and compared with the other two lumps. The well-defined, early 2nd millennium 14 C age of the lime lumps of this particular church is an important contribution to the discussion on stone church chronology in Scandinavia

  5. {sup 14}C chronology of the oldest Scandinavian church in use. An AMS/PIXE study of lime lump carbonate in the mortar

    Energy Technology Data Exchange (ETDEWEB)

    Lindroos, Alf, E-mail: alf.lindroos@abo.fi [Geology and Mineralogy, Department of Natural Sciences, Åbo Akademi University (Finland); Art History, Faculty of Art, Åbo Akademi University (Finland); Ranta, Heikki [Diocese of Lund, Church of Sweden (Sweden); Heinemeier, Jan [AMS " 1" 4C Dating Laboratory, Department of Physics and Astronomy, University of Aarhus (Denmark); Lill, Jan-Olof [Accelerator Laboratory, Turku PET Centre, Åbo Akademi University (Finland)

    2014-07-15

    Mortar dating was applied to newly revealed, original mortar in the church of Dalby in Scania, southern Sweden which is considered to be the oldest still standing church in Scandinavia. Small white lime lumps were sampled by chipping from the supporting pillars in the interior of the church. Special emphasis was in sampling lime lumps because the church is situated in the Scania limestone area and aggregate limestone contamination was anticipated in the bulk mortars. Earlier studies have, however, shown that lime lumps do not contain aggregate material but only possible limestone rests from incomplete calcination. The sampled material was prepared for radiocarbon AMS dating. The carbonate in the lime lumps was hydrolyzed according to the sequential leaching technique developed for the Århus {sup 14}C laboratory in Denmark. Prior to the hydrolysis the lime lumps were examined for dead-carbon contamination using a stereo microscope and cathodoluminescence. The lime lumps displayed heterogeneous carbonate luminescence. This is, however, common and it was not considered a problem because carbonate growth in changing pH/Eh conditions often leads to changing luminescence colors. Two lumps had little dead carbon contamination and an early second millennium {sup 14}C signature. One lump, however, seemed to be heavily contaminated with dead carbon. Since the sample passed the microscopic screening, the leftovers of the lump was subjected to PIXE analysis and compared with the other two lumps. The well-defined, early 2nd millennium {sup 14}C age of the lime lumps of this particular church is an important contribution to the discussion on stone church chronology in Scandinavia.

  6. AMS radiocarbon dating of ancient Japanese sutras

    CERN Document Server

    Oda, H; Nakamura, T; Fujita, K

    2000-01-01

    Radiocarbon ages of ancient Japanese sutras whose historical ages were known paleographically were measured by means of accelerator mass spectrometry (AMS). Calibrated radiocarbon ages of five samples were consistent with the corresponding historical ages; the 'old wood effect' is negligible for ancient Japanese sutras. Japanese paper has been made from fresh branches grown within a few years and the interval from trimming off the branches to writing sutra on the paper is within one year. The good agreement between the calibrated radiocarbon ages and the historical ages is supported by such characteristics of Japanese paper. It is indicated in this study that Japanese sutra is a suitable sample for radiocarbon dating in the historic period because of little gap by 'old wood effect'.

  7. AMS radiocarbon dating of ancient Japanese sutras

    International Nuclear Information System (INIS)

    Oda, Hirotaka; Yoshizawa, Yasukazu; Nakamura, Toshio; Fujita, Keiko

    2000-01-01

    Radiocarbon ages of ancient Japanese sutras whose historical ages were known paleographically were measured by means of accelerator mass spectrometry (AMS). Calibrated radiocarbon ages of five samples were consistent with the corresponding historical ages; the 'old wood effect' is negligible for ancient Japanese sutras. Japanese paper has been made from fresh branches grown within a few years and the interval from trimming off the branches to writing sutra on the paper is within one year. The good agreement between the calibrated radiocarbon ages and the historical ages is supported by such characteristics of Japanese paper. It is indicated in this study that Japanese sutra is a suitable sample for radiocarbon dating in the historic period because of little gap by 'old wood effect'

  8. Revision of Fontes & Garnier's model for the initial 14C content of dissolved inorganic carbon used in groundwater dating

    Science.gov (United States)

    Han, Liang-Feng; Plummer, Niel

    2013-01-01

    The widely applied model for groundwater dating using 14C proposed by Fontes and Garnier (F&G) (Fontes and Garnier, 1979) estimates the initial 14C content in waters from carbonate-rock aquifers affected by isotopic exchange. Usually, the model of F&G is applied in one of two ways: (1) using a single 13C fractionation factor of gaseous CO2 with respect to a solid carbonate mineral, εg/s, regardless of whether the carbon isotopic exchange is controlled by soil CO2 in the unsaturated zone, or by solid carbonate mineral in the saturated zone; or (2) using different fractionation factors if the exchange process is dominated by soil CO2 gas as opposed to solid carbonate mineral (typically calcite). An analysis of the F&G model shows an inadequate conceptualization, resulting in underestimation of the initial 14C values (14C0) for groundwater systems that have undergone isotopic exchange. The degree to which the 14C0 is underestimated increases with the extent of isotopic exchange. Examples show that in extreme cases, the error in calculated adjusted initial 14C values can be more than 20% modern carbon (pmc). A model is derived that revises the mass balance method of F&G by using a modified model conceptualization. The derivation yields a “global” model both for carbon isotopic exchange dominated by gaseous CO2 in the unsaturated zone, and for carbon isotopic exchange dominated by solid carbonate mineral in the saturated zone. However, the revised model requires different parameters for exchange dominated by gaseous CO2 as opposed to exchange dominated by solid carbonate minerals. The revised model for exchange dominated by gaseous CO2 is shown to be identical to the model of Mook (Mook, 1976). For groundwater systems where exchange occurs both in the unsaturated zone and saturated zone, the revised model can still be used; however, 14C0 will be slightly underestimated. Finally, in carbonate systems undergoing complex geochemical reactions, such as oxidation of

  9. Online coupling of pure O_2 thermo-optical methods – "1"4C AMS for source apportionment of carbonaceous aerosols

    International Nuclear Information System (INIS)

    Agrios, Konstantinos; Salazar, Gary; Zhang, Yan-Lin; Uglietti, Chiara; Battaglia, Michael; Luginbühl, Marc; Ciobanu, Viorela Gabriela; Vonwiller, Matthias; Szidat, Sönke

    2015-01-01

    This paper reports on novel separation methods developed for the direct determination of "1"4C in organic carbon (OC) and elemental carbon (EC), two sub-fractions of total carbon (TC) of atmospheric air particulate matter. Until recently, separation of OC and EC has been performed off-line by manual and time-consuming techniques that relied on the collection of massive CO_2 fractions. We present here two on-line hyphenated techniques between a Sunset OC/EC analyzer and a MICADAS (MIni radioCArbon DAting System) accelerator mass spectrometer (AMS) equipped with a gas ion source. The first implementation facilitates the direct measurement in the low sample size range (<10 μg C) with high throughput on a routine basis, while the second explores the potential for a continuous-flow real-time CO_2 gas feed into the ion source. The performance achieved with reference materials and real atmospheric samples will be discussed to draw conclusions on the improvement offered in the field of "1"4C aerosol source apportionment.

  10. Online coupling of pure O{sub 2} thermo-optical methods – {sup 14}C AMS for source apportionment of carbonaceous aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Agrios, Konstantinos [Department of Chemistry and Biochemistry, University of Bern, Bern (Switzerland); Oeschger Centre for Climate Change Research, University of Bern, Bern (Switzerland); Paul Scherrer Institute, Villigen (Switzerland); Salazar, Gary [Department of Chemistry and Biochemistry, University of Bern, Bern (Switzerland); Oeschger Centre for Climate Change Research, University of Bern, Bern (Switzerland); Zhang, Yan-Lin; Uglietti, Chiara [Department of Chemistry and Biochemistry, University of Bern, Bern (Switzerland); Oeschger Centre for Climate Change Research, University of Bern, Bern (Switzerland); Paul Scherrer Institute, Villigen (Switzerland); Battaglia, Michael [Department of Chemistry and Biochemistry, University of Bern, Bern (Switzerland); Oeschger Centre for Climate Change Research, University of Bern, Bern (Switzerland); Luginbühl, Marc [Department of Chemistry and Biochemistry, University of Bern, Bern (Switzerland); Ciobanu, Viorela Gabriela [Paul Scherrer Institute, Villigen (Switzerland); Vonwiller, Matthias [Department of Chemistry and Biochemistry, University of Bern, Bern (Switzerland); Oeschger Centre for Climate Change Research, University of Bern, Bern (Switzerland); Paul Scherrer Institute, Villigen (Switzerland); Szidat, Sönke, E-mail: szidat@dcb.unibe.ch [Department of Chemistry and Biochemistry, University of Bern, Bern (Switzerland); Oeschger Centre for Climate Change Research, University of Bern, Bern (Switzerland)

    2015-10-15

    This paper reports on novel separation methods developed for the direct determination of {sup 14}C in organic carbon (OC) and elemental carbon (EC), two sub-fractions of total carbon (TC) of atmospheric air particulate matter. Until recently, separation of OC and EC has been performed off-line by manual and time-consuming techniques that relied on the collection of massive CO{sub 2} fractions. We present here two on-line hyphenated techniques between a Sunset OC/EC analyzer and a MICADAS (MIni radioCArbon DAting System) accelerator mass spectrometer (AMS) equipped with a gas ion source. The first implementation facilitates the direct measurement in the low sample size range (<10 μg C) with high throughput on a routine basis, while the second explores the potential for a continuous-flow real-time CO{sub 2} gas feed into the ion source. The performance achieved with reference materials and real atmospheric samples will be discussed to draw conclusions on the improvement offered in the field of {sup 14}C aerosol source apportionment.

  11. The first case study of 230Th/U and 14C dating of mid-valdai organic deposits

    Science.gov (United States)

    Maksimov, F. E.; Kuznetsov, V. Yu.; Zaretskaya, N. E.; Subetto, D. A.; Shebotinov, V. V.; Zherebtsov, I. E.; Levchenko, S. B.; Kuznetsov, D. D.; Larsen, E.; Lysö, A.; Jensen, M.

    2011-05-01

    From the viewpoint of precision and reliability of radioisotopic dating, deposits whose quantitative age can be determined through several methods of geochronometry are of special interest. The mutually conforming finite 14C and 230Th/U dates of buried Neopleistocene organic deposits, taken from the Tolokonka section by the North Dvina River (100 km downstream from the city of Kotlas), have been obtained for the first time in Russia. The stratigraphical reference of these results to those obtained via the optically induced luminescence for upper and lower bedding layers has been established. The presented geochronometric data have allowed us to consider the age of oxbow lake organic deposits completely reliable and refer the time of their formation to the Tyrbei warming within the MIS-3. The applicability of the new version of the 230Th/U method for dating of interglacial and interstadial deposits, for the purpose of solving the Middle and Late Neopleistocene chronostratigraphy issues, is confirmed.

  12. Discrepancies in 14C dating as illustrated from the Egyptian new and middle kingdoms and from the Aegean bronze age and neolithic

    International Nuclear Information System (INIS)

    Hood, S.

    1978-01-01

    14 C dates available for the Middle and New Kingdoms in Egypt and for the Bronze Age and Neolithic in the Aegean are examined. The possibility is explored that calibrated dates vary from tree-ring dates by different margins in Egypt and the Aegean during the second millenium B.C. Apparent inconsistencies between 14 C dates from different Neolithic sites in the Aegean area are also noted. (author)

  13. From scrolls to Picasso: AMS radiocarbon dating applied to textiles, art works and artifacts

    International Nuclear Information System (INIS)

    Jull, A.J.T.; Donahue, D.J.; Beck, J.W.; Burr, G.S.; O'Malley, J.; Hewitt, L.; Biddulph, D.; Hatheway, A.L.; Lange, T.E.; Toolin, J.

    1997-01-01

    Full text: The use of accelerator mass spectrometry (AMS) for radiocarbon dating allows us to use very small samples of carbon, 14 C to dating of many types of textiles, including silks and linens, art works, documents and artifacts fabricated from wood, parchment, ivory and bone. For many of these types of samples, the results are often important in questions of the authenticity of these works of art and artifacts. This has encompassed a wide range of art works ranging from the Dead Sea Scrolls, the Shroud of Turin and the Chinese silk trade to the works of Raphael, Rembrandt and Picasso. Most recently, we have also dated the Vinland Map, a controversial document which shows the eastern coast of North America apparently using information from Viking voyages. An important issue in such studies is also the radiocarbon calibration curve. For some periods, most notably 1700-1950 AD we know that several changes in the 14 C composition of the atmosphere make it almost impossible to date a sample during this period more precisely than the entire range. However, before this period, we have successfully dated materials to high precision. We have also studied the use of the period l900-1950 AD for 14 C measurements and will present some examples where the rapid decline in Δ 14 C can be used to date art works. The period after 1950AD also allows us to identify works fabricated from recent materials using the 'spike' in 14 C due to atmospheric nuclear testing. This bomb 14 C has also been successfully used to identify originals from copies of works purporting to be the originals. We will discuss some artifacts, art works and forgeries, where 14 C can resolve problems of authenticity (authors)

  14. Dating raised bogs : New aspects of AMS C-14 wiggle matching, a reservoir effect and climatic change

    NARCIS (Netherlands)

    Kilian, MR; VanDerPlicht, J; VanGeel, B; Geel, B. van

    1995-01-01

    High resolution AMS dating of Holocene raised bog deposits (Engbertsdijksvenen, The Netherlands) shows natural C-14 variations (wiggles) which can be matched with the dendrochronological calibration curve. Comparison of our results with other, conventionally dated peat cores and the Delta(14)C

  15. Characterization of a new protocol for mortar dating: 13C and 14C evidences

    International Nuclear Information System (INIS)

    Marzaioli, F.

    2011-01-01

    This paper reviews the present knowledge about the analysis of mortars in the framework of artworks absolute chronology determination with the aim to formulate a new methodology capable of systematically and accurately estimating the age of these constructive and/or art materials. The core of the proposed methodology is represented by a physical procedure (ultrasonication) selecting only carbonaceous materials represented by carbonates formed after the absorption of atmospheric Co2 (carbonatation) by mortars (binder) during their setting. With the aim to evaluate the procedure efficiency in the isolation of binder signal from the most important source of carbonates, the proposed procedure was tested on a series of laboratory mortars produced, in a simplified version, in the laboratory environment. Mortar production was characterized by means of a series of measurements allowing to draw important indications about the applied procedure. The radiocarbon value of isolated binder carbonates was compared with the Co2 signal sampled form laboratory air during mortar setting. The observed results confirmed preliminarily the good protocol accuracy for radiocarbon dating suggesting its capability for the application to real study cases.

  16. Climate and demography in early prehistory: using calibrated (14)C dates as population proxies.

    Science.gov (United States)

    Riede, Felix

    2009-04-01

    Although difficult to estimate for prehistoric hunter-gatherer populations, demographic variables-population size, density, and the connectedness of demes-are critical for a better understanding of the processes of material culture change, especially in deep prehistory. Demography is the middle-range link between climatic changes and both biological and cultural evolutionary trajectories of human populations. Much of human material culture functions as a buffer against climatic changes, and the study of prehistoric population dynamics, estimated through changing frequencies of calibrated radiocarbon dates, therefore affords insights into how effectively such buffers operated and when they failed. In reviewing a number of case studies (Mesolithic Ireland, the origin of the Bromme culture, and the earliest late glacial human recolonization of southern Scandinavia), I suggest that a greater awareness of demographic processes, and in particular of demographic declines, provides many fresh insights into what structured the archaeological record. I argue that we cannot sideline climatic and environmental factors or extreme geophysical events in our reconstructions of prehistoric culture change. The implications of accepting demographic variability as a departure point for evaluating the archaeological record are discussed.

  17. AMS radiocarbon dating of mortar: The case study of the medieval UNESCO site of Modena

    Energy Technology Data Exchange (ETDEWEB)

    Carmine, Lubritto [Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche & CIRCE lab, Seconda Università degli Studi di Napoli, I-81100 Caserta (Italy); Caroselli, Marta; Lugli, Stefano [Dipartimento di Scienze Chimiche e Geologiche, Università di Modena e Reggio Emilia, I-41100 Modena (Italy); Marzaioli, Fabio [Dipartimento di Matematica e Fisica & CIRCE lab, Seconda Università degli Studi di Napoli, I-81100 Caserta (Italy); Nonni, Sara [Università degli Studi “Sapienza”, Dipartimento di Scienze della Terra, I-00185 Roma (Italy); Marchetti Dori, S. [Dipartimento di Scienze Chimiche e Geologiche, Università di Modena e Reggio Emilia, I-41100 Modena (Italy); Terrasi, Filippo [Dipartimento di Matematica e Fisica & CIRCE lab, Seconda Università degli Studi di Napoli, I-81100 Caserta (Italy)

    2015-10-15

    The carbon dioxide contributing to binder formation during the set of a lime mortar reflects the atmospheric {sup 14}C content at the time of construction of a building. For this reason, the {sup 14}C dating of mortars is used with increasing frequencies in archaeological and architectural research. Mortars, however, may also contain carbonaceous contaminants potentially affecting radiocarbon dating. The Centre for Isotopic Research on Cultural and Environmental heritage (CIRCE) of the Second University of Naples (SUN) has recently obtained some promising results in mortar radiocarbon dating thanks to the development of a procedure (i.e. CryoSoniC/Cryo2SoniC) aiming to eliminate exogenous C contamination that may occur in a mortar. The construction history of the UNESCO World Heritage Site of Modena (Italy) is still controversial and represents a challenging case study for the application of absolute dating methodologies for different reasons. From the point of view of {sup 14}C dating, for example, given the high percentage of carbonate aggregates composing these samples, Modena mortars represent an experimental test particularly indicative of exogenous carbon sources suppression ensuring methodology accuracy. In this paper several AMS Radiocarbon dates were carried out on lime lumps with the aim to: (i) verify procedure accuracy by a comparison of the results obtainable from lime lumps dated after different treatments (i.e. bulk lime lumps vs. CryoSoniC purified lime lumps); (ii) compare different building phases absolute chronology for the medieval UNESCO site of Modena, with that assumed by historical sources in order to assess preliminary the {sup 14}C dating feasibility for of the site. Historical temporal constraints and mortar clustering, based on petrography, have been applied to define a temporal framework of the analyzed structure. Moreover, a detailed petrographic characterization of mortars was used both as a preliminary tool for the choice of samples

  18. First accelerator mass spectrometry {sup 14}C dates documenting contemporaneity of nonanalog species in late Pleistocene mammal communities

    Energy Technology Data Exchange (ETDEWEB)

    Stafford, T.W. Jr.; Semken, H.A. Jr.; Graham, R.W.; Klippel, W.F.; Markova, A.; Smirnov, N.G.; Southon, J.

    1999-10-01

    Worldwide late Pleistocene terrestrial mammal faunas are characterized by stratigraphic associations of species that now have exclusive geographic ranges. These have been interpreted as either taphonomically mixed or representative of communities that no longer exist. Accelerator mass spectrometry {sup 14}C dates (n = 60) on single bones of stratigraphically associated fossil micromammals from two American and two Russian sites document for the first time that currently allopatric mammals occurred together between 12,000 and 22,000 yr B.P. on two continents. The existence of mammal communities without modern analogs demonstrates that Northern Hemisphere biological communities are ephemeral and that many modern biomes are younger than 12 ka. Future climate change may result in new nonanalog communities.

  19. Accelerator mass spectrometry (AMS) dating from the modern age to the past million age

    International Nuclear Information System (INIS)

    Sasa, K.; Nagashima, Y.; Seki, R.; Takahashi, T.; Tosaki, Y.; Sueki, K.; Bessyo, K.; Matsumura, H.; Miura, T.

    2006-01-01

    A multi-nuclide Accelerator Mass Spectrometry system at the University of Tsukuba (Tsukuba AMS system) is able to measure the long-lived radioisotopes of 14 C, 26 Al, 36 Cl and 129 I. The Tsukuba AMS system is able to perform AMS measurements with the terminal voltage of more than 10 MV. It is difficult to estimate the modern age dating (timescale of the past ten years) by the AMS dating method because the low attenuation of long-lived radioisotopes. The atomic bomb-produced radioisotopes are proposed as the environmental traces for the modern age dating. There is the advantage that the long half life of radioisotopes makes the attenuation negligilbe compared with the short half life of radioisotopes. We applied the 36 Cl bomb pulse as a dating tool for modern groundwater (∼50 years) instead of the 3 H bomb pulse. In addition, we have developed 32 Si-AMS system. The half life of 32 Si is about 140 years, therefore 32 Si-AMS is a useful tool for the modern age dating. On the other hand, we have started a new project to measure the cosmogenic nuclide of 36 Cl in an ice core retrieved from Dome Fuji station at Antarctic in order to investigate the past solar activity and the past earth environment as the timescale of the past million age. (author)

  20. C:N:P Molar Ratios, Sources and 14C Dating of Surficial Sediments from the NW Slope of Cuba.

    Directory of Open Access Journals (Sweden)

    Guadalupe de la Lanza Espino

    Full Text Available The surficial sediments recovered from 12 sites located near the channel axis of the Florida Straits and the lower slope off NW Cuba were analyzed for total organic carbon (TOC, nitrogen (TN, phosphorus (TP, elemental C:N:P ratios, C and N isotopic values, and 14C dating. The depth profiles of TOC, TN, and TP (0-18 cm displayed a downcore trend and a significant variation. The TOC values were low (0.15 to 0.62%; 66 to 516 µmol g(-1. Sites near the island's lower slope had lower TOC average concentrations (158-333 µmol g(-1 than those closer to the channel axis (averaging 341-516 µmol g(-1; p <0.05. The TN concentrations near the lower slope attained 0.11% (80 µmol g(-1, whereas, towards the channel axis, they decreased to 0.07% (55 µmol g(-1; p<0.05. The C:N ratios ranged from 1.9 to 10.2. The mean molar C:N ratio (5.4 indicated a marine hemipelagic deposition. The TP was lower at sites near the lower slope (38.4 to 50.0 µmol gv; 0.12% to 0.16% than those near the channel axis (50.0 to 66 µmol g(-1; 0.15 to 0.21%. C:P fluctuated from 7.7 to 14.1 in the surficial sediment layer. The bulk organic δ13Corg and δ15N values confirmed pelagic organic sources, and the 14C dating revealed that the sediments were deposited during the Holocene (1000-5000 yr BP. We suggest that the hydrodynamic conditions in the Straits influence vertical and advective fluxes of particulate organic material trapped in the mixed-layer, which reduces the particulate matter flux to the seabed.

  1. 14 C dating and isotopic composition of lacustrine sediment in the Vale do Ribeira, south-western Sao Paulo State

    International Nuclear Information System (INIS)

    Saia, Soraya E.M.G.; Pessenda, Luiz C.R.; Gouveia, Susy E.M.; Vidotto, Elaine; Ledru, Marie-Pierre; Karmann, Ivo; Amaral, Paula G.; Bendassoli, Jose A.

    2005-01-01

    This work is part of a multi and interdisciplinary study involving paleoenvironmental records based on systematic and joint actions of pollen, isotopic composition ( 12 C, 13 C and 14 N, 15 N) and 14 C dating of lacustrine sediment. Samplings have been made in the Lagoa Grande located at Parque Estadual de Turismo do Alto Ribeira - PETAR, in the Vale do Ribeira, south-western Sao Paulo state. This integration must improve significantly the studies of vegetation and climate changes that occurred during the Late Pleistocene in the southeastern region of Brazil. The δ 13 C results of lacustrine sediment presented values from -23 to -30 per mille with isotopic tendencies of enrichment-depletion in the whole profile. The highest values of total organic carbon (TOC) and C/N associated with depleted δ 13 C values, were linked to organic matter from C 3 land plant and interpreted as the presence of denser arboreal vegetation around the lake. The smallest values of TOC and C/N associated with enriched δ 13 C values were linked to phytoplanktonic influence and/or the presence of less dense arboreal vegetation around the lake. These fluctuations reflect changes in quality and quantity of sedimentary organic matter linked to vegetation changes and the production of organic matter within the sedimentation basin connected with lake level variations. The combination of C/N and δ 13 C data on a cross-plot diagram shows a general distribution of points lying close to the planktonic (algal) organic matter. However, the scattering of certain points indicates a slight contribution from C 3 land plants. The variations in arboreal pollen (%AP) along the core are characterized by AP values between 40 and 80%. The 14C dating indicated Modern age at the shallow horizons to 1,030 years BP for the deeper horizon. (author)

  2. Paleogeography of the Austro-Hungarian Lake Neusiedl - Hansag region in historic times, based on 14C-dating

    International Nuclear Information System (INIS)

    Haeusler, H.; Sauermann, I.; Kovacs, G.; Wild, E.; Steiner, P.

    2007-01-01

    Full text: Based on calibrated 14 C-dating of several peat sections intercalating with fine-grained beds in the Hansag southeast of Lake Neusiedl we present a first approach of the paleogeography of the Austro-Hungarian border region during a time span when first settlements already existed and before the first detailed topographic maps of this region were drawn. About one hundred pits down to one metre were digged out in the Hansag region near Osli in 2003 for studying the recultivation of this regularly flooded area in an environmental geo-information system (GIS). Several sections clearly show an alternation of peat layers intersected by fine-grained fluvio-lacustrine sediments. 15 age determinations of samples from several sections underlying and overlying silty to clayey sediments allow for reconstructing the succession of longer stillwater deposits alternating with peat successions. Comparing the Hansag succession with historic records of the vicinity of Lake Neusiedl allows for a new insight in this unique development of the Lake Neusiedl - Hansag region, at present situated within the Austro-Hungarian national park. It should be recalled, that Lake Neusiedl is Central Europe's largest step lake and Austria's youngest UNESCO World Cultural Heritage site. The paleo-environment of the Lake Neusiedl - Hansag region basically can be designed in four steps by comparing the archaeological findings around Lake Neusiedl with our 14 C-dating of peat layers in the Hansag region: 1: the oldest settlements in the Lake Neusiedl region date about 3600 BC, and 1700 BC respectively. During this periods the lake probably was quite smaller than today. Our 14 C-dating of peat sections in the Hansag region corresponds with these findings, indicating that during a time span of approximately 2000 years until 30 Anno Domini (AD) no bigger lake existed in the Neusiedl- Hansag region. Small pieces of charcoal dating around 2300 BC can have been caused by bush fire and therefore be

  3. AMS radiocarbon dating of 'Grotta Cappuccini' in Southern Italy

    International Nuclear Information System (INIS)

    Quarta, G.; Calcagnile, L.; D'Elia, M.; Rizzo, A.; Ingravallo, E.

    2004-01-01

    We present the results of AMS radiocarbon dating of human bones recovered in 'Grotta Cappuccini', a prehistoric cave in Galatone, Lecce (Southern Italy). The AMS analysis has confirmed the archaeological dating of the cave to the period between the end of the Copper Age and the early Bronze Age, and has given a fundamental contribution to the chronological definition of an important cultural aspect of the prehistory of Southern Italy

  4. δ13C and 14C dating of sediments in Santa Cruz do Arari, Marajo Island (Brazil)

    International Nuclear Information System (INIS)

    Lima, Claudia More de; Pessenda, Luiz Carlos Ruiz; Rossetti, Dilce de Fatima; Rosario, Carlos da Silva; Silva, Carlos Alberto Santos da

    2007-01-01

    The eastern domain of Marajo Island, in the surroundings of Santa Cruz do Arari (Para State), is occupied by holocenic sedimentary deposits, at present covered predominantly by natural grasslands. The analysis of stable carbon isotopes in organic matter of these sediments has been applied with the objective of to evaluate the paleovegetation dynamics, the retreat or the expansion of the Amazonian Forest (located in the westerner domain) over the different types of natural grasslands in Marajo Island, during Late Quaternary. From 3.60 m to 1.80 m the δ 13 C results are around -25 (reaching value up to -29 per mille) and indicate that the organic matter of these sediments are originated from C3 plants. In the interval of 1.80 m until 0.90 m all the samples present a gradual enrichment of 13 C, indicating a higher influence of C4 plants in the vegetation cover. The intermediate δ 13 C values found in those depths (from -22 per mille to -18 per mille) indicate a mixture of C3 and C4 plants with gradual increase of areas with C4 plants. From 0.90 m to the shallow layer the δ 13 C values show a tendency to more depleted values, indicating higher influence of C3 plants in the recent and present period. The results demonstrate that the vegetation dynamics was significant in the Marajo Island from the past to the present. The chronology of these events is being determined by the 14 C dating technique and possible causes (climatic, anthropogenic and/or neotectonic) for such changes investigate. (author)

  5. AMS radiocarbon dating of mortar: The case study of the medieval UNESCO site of Modena

    International Nuclear Information System (INIS)

    Carmine, Lubritto; Caroselli, Marta; Lugli, Stefano; Marzaioli, Fabio; Nonni, Sara; Marchetti Dori, S.; Terrasi, Filippo

    2015-01-01

    The carbon dioxide contributing to binder formation during the set of a lime mortar reflects the atmospheric "1"4C content at the time of construction of a building. For this reason, the "1"4C dating of mortars is used with increasing frequencies in archaeological and architectural research. Mortars, however, may also contain carbonaceous contaminants potentially affecting radiocarbon dating. The Centre for Isotopic Research on Cultural and Environmental heritage (CIRCE) of the Second University of Naples (SUN) has recently obtained some promising results in mortar radiocarbon dating thanks to the development of a procedure (i.e. CryoSoniC/Cryo2SoniC) aiming to eliminate exogenous C contamination that may occur in a mortar. The construction history of the UNESCO World Heritage Site of Modena (Italy) is still controversial and represents a challenging case study for the application of absolute dating methodologies for different reasons. From the point of view of "1"4C dating, for example, given the high percentage of carbonate aggregates composing these samples, Modena mortars represent an experimental test particularly indicative of exogenous carbon sources suppression ensuring methodology accuracy. In this paper several AMS Radiocarbon dates were carried out on lime lumps with the aim to: (i) verify procedure accuracy by a comparison of the results obtainable from lime lumps dated after different treatments (i.e. bulk lime lumps vs. CryoSoniC purified lime lumps); (ii) compare different building phases absolute chronology for the medieval UNESCO site of Modena, with that assumed by historical sources in order to assess preliminary the "1"4C dating feasibility for of the site. Historical temporal constraints and mortar clustering, based on petrography, have been applied to define a temporal framework of the analyzed structure. Moreover, a detailed petrographic characterization of mortars was used both as a preliminary tool for the choice of samples and to infer

  6. AMS radiocarbon dating of lacustrine sediment from an impact crater in northeastern China

    Energy Technology Data Exchange (ETDEWEB)

    Liu, K.X. [State Key Laboratory of Nuclear Physics and Technology and Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing 100871 (China); Chen, M., E-mail: mchen@gig.ac.cn [Key Laboratory of Mineralogy and Metallogeny, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 510640 Guangzhou (China); Ding, X.F.; Fu, D.P. [State Key Laboratory of Nuclear Physics and Technology and Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing 100871 (China); Ding, P. [State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 510640 Guangzhou (China); Shen, C.D., E-mail: cdshen@gig.ac.cn [State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 510640 Guangzhou (China); Xiao, W.S. [Key Laboratory of Mineralogy and Metallogeny, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 510640 Guangzhou (China)

    2013-01-15

    In order to investigate the origin and age of a bowl-shaped crater with 1.8 km diameter in northeastern China, a core drilling about 110 m in total was carried out in 2009 at the center of the crater. A 106-m-thick unit of lacustrine sediment is revealed under a surface layer of about 1 m of yellow soil. The impact origin has been confirmed based on geological analysis. In this paper, we report the AMS {sup 14}C dating results of lacustrine sediment. The data suggest that the meteorite impact in Xiuyan happened more than 50,000 years ago and a two-section linear relationship of {sup 14}C ages with the depth shows a stable sediment environment through the two time stages.

  7. Measuring transfer of 14C-PCB from maternal diet to milk in a goat model using an accelerator mass spectrometer (AMS)

    International Nuclear Information System (INIS)

    Janle, E.; Sojka, J.; Jackson, G.S.; Lachcik, P.; Einstien, J.A.; Santerre, C.R.

    2007-01-01

    Environmental pollutants pose a substantial risk to nursing infants. Many of these toxicants (i.e. PCBs, PBDEs, mercury) are passed from the maternal diet to the nursing infant in breast milk. Determining the toxicokinetics has been difficult to measure due to ethical limitations. Since extremely small amounts of 14 C can be measured using Accelerator Mass Spectrometry (AMS), a goat model was used to establish a minimum oral dose of 14 C-labeled PCB (2,2',4,4',5,5'-hexachlorobiphenyl-UL- 14 C) that could be given to a lactating animal and traced into the milk. An oral dose of 66 nCi/kg body weight (1.84 μg PCB/kg bw) was administered. Plasma and milk samples were collected for 2 months after dosing. The concentration of 14 C label reached a peak value of 1.71 ng/ml PCB equivalents in the milk on day 2 and then declined to about 135 pg/ml PCB equivalents in the milk at 3 weeks. A second goat was administered a smaller dose (22 nCi/kg bw; 616 ng PCB/kg bw). A peak concentration of 485 pg PCB equivalents/ml milk occurred at 3 days and declined to 77.6 pg PCB equivalents/ml milk by 3 weeks. Our results indicated that an even lower dosage of labeled-PCB could be used due to the extreme sensitivity of AMS measurement. Extrapolating from current data it is estimated that the dose could be reduced by a factor of 20 (31 ng PCB/kg bw; 1.1 nCi/kg bw) and still be detectable after 2 months. Thus, the potential exists for developing protocols for studying toxicokinetics in humans using radiologically- and toxicologically-benign doses of labeled environmental toxicants

  8. Direct dating of the oxygen-isotope record of the last deglaciation by 14C accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Duplessy, J.C.; Arnold, Maurice; Maurice, Pierre; Bard, Edouard; Duprat, Josette; Moyes, Jean

    1986-01-01

    The authors have measured 14 C for various species of foraminifera to produce a reliable timescale for the oxygen-isotope record. The results show that, at the end of the last ice age, continental ice sheets began to melt more than 4,000 yr before the Northern Hemisphere maximum of summer calorific radiation. (author)

  9. The rates of carbon cycling in several soils from AMS14C measurements of fractionated soil organic matter

    International Nuclear Information System (INIS)

    Trumbore, S.E.; Bonani, G.; Wolfli, W.

    1990-01-01

    14 C mean residence times (MRT) of fractionated organic matter are reported for three pre-bomb soil profiles. Comparisons of organic matter extracted with acid and base showed that the longest MRTs were associated with the non-acid-hydrolysable fraction. The MRT of organic matter in a soil layer represents a combination of the rates of several processes, including decay to CO 2 and transport out of the layer. In some instances (notably in the A horizon of the Podzol soil studied in this paper), the MRT is dominated by the rate of transport, rather than the rate of decay. Thus it is important to use the distribution and balance of carbon in the soil profile to assess the meaning of the MRT with respect to influencing atmospheric CO 2

  10. AMS radiocarbon dating of cemetery of Jin Marquises in China

    CERN Document Server

    Wu, X; Wang, J; Guo, Z; Liu, K; Lü, X; Ma, H; Li, K; Yuan, J; Cai, L

    2000-01-01

    Bones are very important samples to determine the hosts of the cemetery of Jin Marquises which were excavated at Tianma-Qucun site in Shanxi Province in China. In order to obtain accurate AMS radiocarbon dates, bones were pretreated by two kinds of methods, the gelatin-extraction method and the amino-acid method. Charcoals collected from the same sites were also used. The measured dates agree with historical record.

  11. AMS radiocarbon dating of ancient Japanese documents of known age

    International Nuclear Information System (INIS)

    Oda, H.; Niu, E.; Nakamura, T.

    2003-01-01

    Radiocarbon ages of 17 ancient Japanese documents of known age and 3 unknown samples were measured by AMS. Radiocarbon dating on the known documents concluded that the Japanese paper is a suitable sample for radiocarbon dating because of small discrepancy between the calibrated radiocarbon age and the historical age due to the characteristics of Japanese paper. From the dating of the paper samples of unknown age, the wood-block prints, it was clarified that they had been produced between the 11th century and the first half of the 12th century as the historical information suggested. (author)

  12. Radio carbonic dates (14C) from Dolores Fm. (Santa Lucia River,Canelones Department and Gutierrez chico Creek,Rio Negro Department)and comments about the vertebrate fauna associated

    International Nuclear Information System (INIS)

    Ubilla, M.

    1999-01-01

    Radiometric dates(14C)were performed based on fossil woods coming from late Pleistocene levels and assigned to dolores Fm.(Rio Negro Department, Gutierrez Chico Creek: Canelones Department, Danta Lucia basin).The 14C ages date the fossiliferous levels near the Pleistocene-Holocene boundary: 10.480+/-100 y B.P.(LP-1110,wood in det.), 10.500+/-110 y B.P. (LP-1143.wood in det.)and 11.650+/130 y B.P.(LP-509, Prosopis?sp.).Several ta xa of mammals recorded in the Dolores Fm.characterise the late Pleistocene of South Am erica( L ujunian f auna).Accordingly with the 14 dates, the most recent record of mega fauna of Uruguay is here reported.Archaeological sites with mega fauna have been described from other localities of South America with similar radiometric dates.In spite of the current controversy about the regional finipleistocenic climatic oscillation,the scarcely fossiliferous evidences suggest arid to semiarid and cold climatic condition.These evidences must be improved to test accurately the regional climatic hypothesis

  13. Analysis of 14C and 13C in teeth provides precise birth dating and clues to geographical origin

    OpenAIRE

    K, Alkass; BA, Buchholz; H, Druid; KL, Spalding

    2011-01-01

    The identification of human bodies in situations when there are no clues as to the person’s identity from circumstantial data, poses a difficult problem to investigators. The determination of age and sex of the body can be crucial in order to limit the search to individuals that are a possible match. We analyzed the proportion of bomb pulse derived carbon-14 (14C) incorporated in the enamel of teeth from individuals from different geographical locations. The ‘bomb pulse’ refers to a significa...

  14. 14C dating and isotopic composition of mangrove soil in the Parque Estadual da Ilha do Cardoso, Southern Sao Paulo State

    International Nuclear Information System (INIS)

    Vidotto, Elaine; Pessenda, Luiz Carlos Ruiz; Gouveia, Susy Eli M.; Bendassolli, Jose Albertino; Ricardi-Branco, Fresia; Aravena, Ramon

    2007-01-01

    This work is part of a study involving paleoenvironmental records based on pollen analysis, isotopic composition ( 12 C, 13 C and 14 N, 15 N) and 14 C dating of mangrove soil. Samplings have been made in the Jacariu mangrove located at Parque Estadual da Ilha do Cardoso, Cananeia, southern Sao Paulo state. This study must improve significantly the studies of vegetation and climate changes that occurred during the late Holocene (approximately the last 2000 years) in the southeastern region of Brazil. The δ 13 C results of mangrove soil presented values from -24 to -26 per mille The values of TOC and C/N associated with δ 13 C values indicated the predominance of organic matter from C 3 land plant and phytoplankton (algal) in the whole profile. The 14 C dating indicated Modern age at the shallow horizons to 1810 years B.P. for the deeper horizon. (author)

  15. The interpretation of archaeological dates from an AMS perspective

    International Nuclear Information System (INIS)

    Zoppi, U.; Sagona, A.; Siegele, R.; Hua, Q.; Jacobsen, G.; Lawson, E.M.

    2001-01-01

    The XVII century saw the establishment of the scientific method and scholars such as Galileo were giving excellent contributions to a variety of fields ranging from the natural sciences to the humanities. At the dawn of the new millenium, after a period of excessive specialization, the scientific climate is once again encouraging broad collaborations across different disciplines. For projects involving AMS measurements in general and radiocarbon dating in particular, the benefits of this new trend are numerous. For example, the full potential of the radiocarbon dating method can be exploited only through the mutual understanding of the problems related to sample selection, chemical preparation, AMS measurement, data analysis and interpretation. This paper is intended to enhance the exchange of information by reporting to our current and potential collaborators about the latest technical developments undertaken at the ANTARES AMS facility at ANSTO. Furthermore, we will present two splendid examples of collaborative research: the radiocarbon dating of a replica of a famous chesspiece and the archaeological investigations at the ancient settlement of Sos Hoyuk (north-eastern Anatolia, Turkey) where the multidisciplinary approach was the key to a better understanding of the social structure, settlement patterns, land use and cultural contact, especially with the lands of Trans-Caucasus. (author). 12 refs., 4 figs

  16. 226Ra measurement by thermal ionisation mass spectrometry: Use of 226Ra and 14C for groundwater dating

    International Nuclear Information System (INIS)

    Dever, L.

    1997-01-01

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

  17. 14C dating of freshwater carbonate sediments with special reference to calcareous tufas and laminated lake sediments

    International Nuclear Information System (INIS)

    Pazdur, M.F.

    1992-09-01

    The sequence of laminated sediment of the lake Gosciaz, Poland, covers more than 13,000 years and is actually the longest sequence known so far. Besides of reconstructing past environmental changes, this sequence offers an excellent possibility for studying natural C-14 variations and calibrating the C-14 time scale in a range beyond 6,000 years B.P. The floating varve chronology based on previously taken sediment cores which cover a period of 9,682 years, has been improved by this study. Relative water level changes of the lake during the past 11,500 years have been reconstructed by means of C-14 and C-13 measurements carried out on carbonate fractions of the lake sediments. Periodical variations in the width of annual layers were found. The periods identified are 11 years and 22 years (solar cycle), 35 years (Bruckner cycle), and 200 years. The ratio of summer layer width and the total width of the annual layer shows secular changes which correlate with paleotemperature records. The duration of the Younger Dryas period was determined by combining the floating varve chronology with isotope and pollen analyses of the sediment material. A value of 1,500 years was found. The study also included radiocarbon dating of calcareous tufa taken from different study areas. 26 refs, 26 figs, 6 tabs

  18. Summed Probability Distribution of 14C Dates Suggests Regional Divergences in the Population Dynamics of the Jomon Period in Eastern Japan.

    Directory of Open Access Journals (Sweden)

    Enrico R Crema

    Full Text Available Recent advances in the use of summed probability distribution (SPD of calibrated 14C dates have opened new possibilities for studying prehistoric demography. The degree of correlation between climate change and population dynamics can now be accurately quantified, and divergences in the demographic history of distinct geographic areas can be statistically assessed. Here we contribute to this research agenda by reconstructing the prehistoric population change of Jomon hunter-gatherers between 7,000 and 3,000 cal BP. We collected 1,433 14C dates from three different regions in Eastern Japan (Kanto, Aomori and Hokkaido and established that the observed fluctuations in the SPDs were statistically significant. We also introduced a new non-parametric permutation test for comparing multiple sets of SPDs that highlights point of divergences in the population history of different geographic regions. Our analyses indicate a general rise-and-fall pattern shared by the three regions but also some key regional differences during the 6th millennium cal BP. The results confirm some of the patterns suggested by previous archaeological studies based on house and site counts but offer statistical significance and an absolute chronological framework that will enable future studies aiming to establish potential correlation with climatic changes.

  19. {sup 14}C dating and isotopic composition of mangrove soil in the Parque Estadual da Ilha do Cardoso, Southern Sao Paulo State

    Energy Technology Data Exchange (ETDEWEB)

    Vidotto, Elaine; Pessenda, Luiz Carlos Ruiz; Gouveia, Susy Eli M.; Bendassolli, Jose Albertino [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil)]. E-mails: evidotto@cena.usp.br; pessenda@cena.usp.br; susyeli@cena.usp.br; jab@cena.usp.br; Ricardi-Branco, Fresia [Universidade Estadual de Campinas (UNICAMP), SP (Brazil)]. E-mail: fresia@ige.unicamp.br; Aravena, Ramon [University of Waterloo, Ontario (Canada)]. E-mail: roaraven@sciborg.uwaterloo.ca

    2007-07-01

    This work is part of a study involving paleoenvironmental records based on pollen analysis, isotopic composition ({sup 12}C, {sup 13}C and {sup 14}N, {sup 15}N) and {sup 14}C dating of mangrove soil. Samplings have been made in the Jacariu mangrove located at Parque Estadual da Ilha do Cardoso, Cananeia, southern Sao Paulo state. This study must improve significantly the studies of vegetation and climate changes that occurred during the late Holocene (approximately the last 2000 years) in the southeastern region of Brazil. The {delta}{sup 13}C results of mangrove soil presented values from -24 to -26 per mille The values of TOC and C/N associated with {delta}{sup 13}C values indicated the predominance of organic matter from C{sub 3} land plant and phytoplankton (algal) in the whole profile. The {sup 14}C dating indicated Modern age at the shallow horizons to 1810 years B.P. for the deeper horizon. (author)

  20. Holocene megathermal abrupt environmental changes derived from {sup 14}C dating of a coral reef at Leizhou Peninsula, South China Sea

    Energy Technology Data Exchange (ETDEWEB)

    Shen Chengde; Yi Weixi E-mail: cdshen@gig.ac.cn; Yu Kefu; Sun Yanmin; Liu Tungsheng; Beer, J.; Hajdas, I.; Bonani, G

    2004-08-01

    A depth profile of a Goniopora coral reef at Leizhou Peninsula, South China Sea, was radiocarbon dated using liquid scintillation counting (LSC) and accelerator mass spectrometry (AMS). The time of formation, during 6600-7400 cal BP, can be divided into nine stages, each terminated by abrupt growth cessation of Goniopora and appearance of Ostrea shells. The results show that, during the Holocene megathermal (8.2-3.3 ka BP), large climatic changes have occurred in the South China Sea area.

  1. {sup 14}C AMS measurements in tree rings to estimate local fossil CO{sub 2} in Bosco Fontana forest (Mantova, Italy)

    Energy Technology Data Exchange (ETDEWEB)

    Capano, Manuela, E-mail: capanomanuela@tiscali.i [CIRCE, Dipartimento di Scienze Ambientali, Seconda Universita di Napoli, and INNOVA, Via Vivaldi, 43 81100 Caserta (Italy); Marzaioli, Fabio; Sirignano, Carmina; Altieri, Simona; Lubritto, Carmine; D' Onofrio, Antonio; Terrasi, Filippo [CIRCE, Dipartimento di Scienze Ambientali, Seconda Universita di Napoli, and INNOVA, Via Vivaldi, 43 81100 Caserta (Italy)

    2010-04-15

    Radiocarbon concentration in atmosphere changes overtime due to anthropogenic and natural factors. Species growth preserves the local atmospheric radiocarbon signature over their life span in the annual tree rings and make it possible to use tree rings for the monitoring of changes in fossil-fuel emissions due to an increase of traffic exhaust, during the last decades. In this paper, the CIRCE AMS system has been used to measure the {sup 14}C concentration in tree rings of plants grown near an industrial area and a very busy State Road, in a forest in north Italy. Preliminary results related to tree rings of several years of plants respectively near and far the emitting sources are displayed, in order to estimate the local pollution effect. It is possible to find a dilution in years 2000 and 2006 in both the trees analysed, but not enough data have been analysed yet in order to distinguish the fossil dilution derived from the street vehicular traffic or that from the industries.

  2. Separating the wheat from the chaff: Dating charred plant remains extracted from Daub (with reference to the 14C chronology of the Epi-Lengyel culture in Upper Silesia)

    Czech Academy of Sciences Publication Activity Database

    Chmielewski, T. J.; Sady, A.; Goslar, T.; Furmanek, M.; Juchelka, Jiří

    2017-01-01

    Roč. 59, č. 1 (2017), s. 251-268 ISSN 0033-8222 Institutional support: RVO:68081758 Keywords : food residue * dates * pottery * bones * ams * radiocarbon AMS dating * chaff temper dating * Eneolithic * epi-Lengyel * Upper Silesia Subject RIV: AC - Archeology, Anthropology, Ethnology OBOR OECD: Archaeology Impact factor: 1.280, year: 2016

  3. 14C Analysis of protein extracts from Bacillus spores.

    Science.gov (United States)

    Cappuccio, Jenny A; Falso, Miranda J Sarachine; Kashgarian, Michaele; Buchholz, Bruce A

    2014-07-01

    Investigators of bioagent incidents or interdicted materials need validated, independent analytical methods that will allow them to distinguish between recently made bioagent samples versus material drawn from the archives of a historical program. Heterotrophic bacteria convert the carbon in their food sources, growth substrate or culture media, into the biomolecules they need. The F(14)C (fraction modern radiocarbon) of a variety of media, Bacillus spores, and separated proteins from Bacillus spores was measured by accelerator mass spectrometry (AMS). AMS precisely measures F(14)C values of biological materials and has been used to date the synthesis of biomaterials over the bomb pulse era (1955 to present). The F(14)C of Bacillus spores reflects the radiocarbon content of the media in which they were grown. In a survey of commercial media we found that the F(14)C value indicated that carbon sources for the media were alive within about a year of the date of manufacture and generally of terrestrial origin. Hence, bacteria and their products can be dated using their (14)C signature. Bacillus spore samples were generated onsite with defined media and carbon free purification and also obtained from archived material. Using mechanical lysis and a variety of washes with carbon free acids and bases, contaminant carbon was removed from soluble proteins to enable accurate (14)C bomb-pulse dating. Since media is contemporary, (14)C bomb-pulse dating of isolated soluble proteins can be used to distinguish between historical archives of bioagents and those produced from recent media. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  4. 14C analysis via intracavity optogalvanic spectroscopy

    International Nuclear Information System (INIS)

    Murnick, Daniel; Dogru, Ozgur; Ilkmen, Erhan

    2010-01-01

    A new ultra sensitive laser-based analytical technique, intracavity optogalvanic spectroscopy (ICOGS), allowing extremely high sensitivity for detection of 14 C-labeled carbon dioxide has recently been demonstrated. Capable of replacing accelerator mass spectrometers (AMS) for many applications, the technique quantifies zeptomoles of 14 C in sub micromole CO 2 samples. Based on the specificity of narrow laser resonances coupled with the sensitivity provided by standing waves in an optical cavity, and detection via impedance variations, limits of detection near 10 -1514 C/ 12 C ratios have been obtained with theoretical limits much lower. Using a 15 W 14 CO 2 laser, a linear calibration with samples from 5 x 10 -15 to >1.5 x 10 -12 in 14 C/ 12 C ratios, as determined by AMS, was demonstrated. Calibration becomes non-linear over larger concentration ranges due to interactions between CO 2 and buffer gas, laser saturation effects and changes in equilibration time constants. The instrument is small (table top), low maintenance and can be coupled to GC or LC input. The method can also be applied to detection of other trace entities. Possible applications include microdosing studies in drug development, individualized sub-therapeutic tests of drug metabolism, carbon dating and real time monitoring of atmospheric radiocarbon.

  5. Anthropogenic contributions to atmospheric Hg, Pb and As accumulation recorded by peat cores from southern Greenland and Denmark dated using the 14C "bomb pulse curve"

    Science.gov (United States)

    Shotyk, W.; Goodsite, M. E.; Roos-Barraclough, F.; Frei, R.; Heinemeier, J.; Asmund, G.; Lohse, C.; Hansen, T. S.

    2003-11-01

    Mercury concentrations are clearly elevated in the surface and sub-surface layers of peat cores collected from a minerotrophic ("groundwater-fed") fen in southern Greenland (GL) and an ombrotrophic ("rainwater-fed") bog in Denmark (DK). Using 14C to precisely date samples since ca. AD 1950 using the "atmospheric bomb pulse," the chronology of Hg accumulation in GL is remarkably similar to the bog in DK where Hg was supplied only by atmospheric deposition: this suggests not only that Hg has been supplied to the surface layers of the minerotrophic core (GL) primarily by atmospheric inputs, but also that the peat cores have preserved a consistent record of the changing rates of atmospheric Hg accumulation. The lowest Hg fluxes in the GL core (0.3 to 0.5 μg/m 2/yr) were found in peats dating from AD 550 to AD 975, compared to the maximum of 164 μg/m 2/yr in AD 1953. Atmospheric Hg accumulation rates have since declined, with the value for 1995 (14 μg/m 2/yr) comparable to the value for 1995 obtained by published studies of atmospheric transport modelling (12 μg/m 2/yr). The greatest rates of atmospheric Hg accumulation in the DK core are also found in the sample dating from AD 1953 and are comparable in magnitude (184 μg/m 2/yr) to the GL core; again, the fluxes have since gone into strong decline. The accumulation rates recorded by the peat core for AD 1994 (14 μg/m 2/yr) are also comparable to the value for 1995 obtained by atmospheric transport modelling (18 μg/m 2/yr). Comparing the Pb/Ti and As/Ti ratios of the DK samples with the corresponding crustal ratios (or "natural background values" for preanthropogenic peat) shows that the samples dating from 1953 also contain the maximum concentration of "excess" Pb and As. The synchroneity of the enrichments of all three elements (Hg, Pb, and As) suggests a common source, with coal-burning the most likely candidate. Independent support for this interpretation was obtained from the Pb isotope data ( 206Pb/ 207Pb

  6. Radiocarbon dates from the Oxford AMS system: Archaeometry datelist 17

    International Nuclear Information System (INIS)

    Hedges, R.E.M.; Housley, R.A.; Ramsey, C.B.; Van Klinken, G.J.

    1993-01-01

    This seventeenth list of accelerator dates consists mainly of material dated since the beginning of 1991, but includes a number of measurements made earlier in the dating programme. In accordance with international radiocarbon convention all dates are expressed in radiocarbon years before AD 1950 (years BP) using the half-life of 5568 years, this convention having been reaffirmed at the Trondheim Radiocarbon Conference 1985. Errors are quoted as one standard deviation and are based on an assessment of all the contributions to the error in the laboratory isotope ratio measurement. Natural fractionation of carbon isotopes is accounted for by estimating δ 13 C values except for more recent dates where δ 13 C have been measured relative to PDB (only to within ± 0.5-1.0%). All combining procedures and significance tests are based on Ward and Wilson (1978). Comments composed by the Laboratory on the basis of information supplied by submitters are given without attribution. (author)

  7. Reassessment of the C-13/C-12 and C-14/C-12 isotopic fractionation ratio and its impact on high-precision radiocarbon dating

    NARCIS (Netherlands)

    Fahrni, Simon M.; Southon, John R.; Santos, Guaciara M.; Palstra, Sanne W. L.; Meijer, Harro A. J.; Xu, Xiaomei

    2017-01-01

    The vast majority of radiocarbon measurement results (C-14/C-12 isotopic ratios or sample activities) are corrected for isotopic fractionation processes (measured as C-13/C-12 isotopic ratios) that occur in nature, in sample preparation and measurement. In 1954 Harmon Craig suggested a value of 2.0

  8. AMS exposure dating : a case study from Himalaya and Tibet and its application potentials in earth science studies in India

    International Nuclear Information System (INIS)

    Sharma, K.K.

    1999-01-01

    The development of accelerator mass spectrometry (AMS) has made possible low level (10 -6 atoms/gm) measurements of 10 Be, 14 C, 26 Al, 36 Cl, 129 I isotopes in geological materials. Early studies investigated 10 Be atoms of cosmogenic nuclides produced mainly in the atmosphere (called garden variety), which subsequently admixed with the geological material from land surfaces get transported into the ocean waters and fixed in the ocean sediments. Subsequently, focus shifted to in-situ produced long-lived isotopes in quartz and their measurement in the terrestrial samples. This opened a new field of exposure dating and its potential applications in earth sciences and their role to study the time controlled processes resulting in diverse geomorphic landforms

  9. Isotopic and molecular fractionation in combustion; three routes to molecular marker validation, including direct molecular 'dating' (GC/AMS)

    Science.gov (United States)

    Currie, L. A.; Klouda, G. A.; Benner, B. A.; Garrity, K.; Eglinton, T. I.

    The identification of unique isotopic, elemental, and molecular markers for sources of combustion aerosol has growing practical importance because of the potential effects of fine particle aerosol on health, visibility and global climate. It is urgent, therefore, that substantial efforts be directed toward the validation of assumptions involving the use of such tracers for source apportionment. We describe here three independent routes toward carbonaceous aerosol molecular marker identification and validation: (1) tracer regression and multivariate statistical techniques applied to field measurements of mixed source, carbonaceous aerosols; (2) a new development in aerosol 14C metrology: direct, pure compound accelerator mass spectrometry (AMS) by off-line GC/AMS ('molecular dating'); and (3) direct observation of isotopic and molecular source emissions during controlled laboratory combustion of specific fuels. Findings from the combined studies include: independent support for benzo( ghi)perylene as a motor vehicle tracer from the first (statistical) and second (direct 'dating') studies; a new indication, from the third (controlled combustion) study, of a relation between 13C isotopic fractionation and PAH molecular fractionation, also linked with fuel and stage of combustion; and quantitative data showing the influence of both fuel type and combustion conditions on the yields of such species as elemental carbon and PAH, reinforcing the importance of exercising caution when applying presumed conservative elemental or organic tracers to fossil or biomass burning field data as in the first study.

  10. 14C Accelerator mass spectrometry in Brazil

    International Nuclear Information System (INIS)

    Macario, K.D.; Gomes, P.R.S.; Anjos, Roberto M.; Linares, R.; Queiroz, E.A.; Oliveira, F.M.; Cardozo, L.; Carvalho, C.R.A.

    2011-01-01

    Radiocarbon Accelerator Mass Spectrometry is an ultra-sensitive technique that enables the direct measurement of carbon isotopes in samples as small as a few milligrams. The possibility of dating or tracing rare or even compound specific carbon samples has application in many fields of science such as Archaeology, Geosciences and Biomedicine. Several kinds of material such as wood, charcoal, carbonate and bone can be chemically treated and converted to graphite to be measured in the accelerator system. The Physics Institute of Universidade Federal Fluminense (UFF), in Brazil will soon be able to perform the complete 14 C-AMS measurement of samples. At the Nuclear Chronology Laboratory (LACRON) samples are prepared and converted to carbon dioxide. A stainless steel vacuum system was constructed for carbon dioxide purification and graphitization is performed in sealed tubes in a muffle oven. Graphite samples will be analyzed in a 250 kV Single Stage Accelerator produced by National Electrostatic Corporation which will be installed in the beginning of 2012. With the sample preparation laboratory at LACRON and the SSAMS system, the Physics Institute of UFF will be the first 14 C-AMS facility in Latin America. (author)

  11. Development of a method to measure the concentration of 14C in the stack air of nuclear power plants by accelerator mass spectrometry (AMS)

    International Nuclear Information System (INIS)

    Stenstroem, K.; Erlandsson, B.; Hellborg, R.; Haakansson, K.; Wiebert, A.; Skog, G.

    1993-04-01

    C-14, a pure low-energetic beta-emitter, is produced through various nuclear reactions in nuclear power plants. Some of this C-14 is air-borne and is transported via the ventilation system through the stack of the power station and is integrated in living matter in the surroundings of the plant. The long half-life of the isotope (T1/2=5730 years) and the biological importance of carbon may lead to a not negligible contribution of the radiation dose for those living in the neighbourhood of nuclear power plants. C-14 has earlier been measured radiometrically with mainly two different methods, using proportional counters or liquid scintillators. In this report a new method is described, using an accelerator based technique. accelerator mass spectrometry (AMS). This technique has at least three advantages over the radiometrical methods. It requires only a few litres of gas per sample, which is 100-1000 times less compared to the radiometrical methods. It is insensitive to the beta and gamma rays from other radioactive isotopes in the stack air. The measuring time with AMS, about 20 minutes per sample, is considerably shorter compared to the radiometrical methods, which demand several hours per sample. The integrity of the AMS method is high and it might be convenient for regulatory supervision. (22 refs.)

  12. The use of AMS radiocarbon dating for Xia-Shang-Zhou chronology

    CERN Document Server

    Guo, Z Y; LiuKeXin; Lu Xiang Yang; Ma Hong Ji; Wu Xiao Hon; Yuan Si Xun

    2000-01-01

    The possibility and problems of using radiocarbon dating to historical chronology are discussed. The current situation of ancient Chinese chronology and the project of Xia-Shang-Zhou chronology are introduced. A chronological study requires the AMS radiocarbon dating with high precision, high reliability and high efficiency. The Peking University AMS facility (PKUAMS) has been upgraded and a series of quality control steps were adopted. To reduce the error of calendar age, wiggle matching with serial samples should be used. Some preliminary results of Xia-Shang-Zhou chronology are presented.

  13. Desert Habitation History by 14C Dating of Soil Layers in Rural Building Structures (Negev, Israel) : Preliminary Results from Horvat Haluqim

    NARCIS (Netherlands)

    Bruins, Hendrik J.; van der Plicht, Johannes; Haiman, Mordechai

    2012-01-01

    Traditional archaeological approaches in the central Negev Desert used to employ excavation techniques in post-prehistoric periods in which stratigraphy is based on architecture, while material culture forms the basis for dating assessment and chronology. Such an approach was understandable, as it

  14. An update on in situ cosmogenic {sup 14}C analysis at ETH Zuerich

    Energy Technology Data Exchange (ETDEWEB)

    Hippe, K., E-mail: hippe@erdw.ethz.ch [Institute of Geochemistry and Petrology, ETH Zuerich, Zuerich CH-8092 (Switzerland); Kober, F. [Institute of Geology, ETH Zuerich, Zuerich CH-8092 (Switzerland); Wacker, L. [Institute for Particle Physics, ETH Zuerich, Zuerich CH-8093 (Switzerland); Fahrni, S.M. [Institute for Particle Physics, ETH Zuerich, Zuerich CH-8093 (Switzerland); Department of Chemistry and Biochemistry, University of Bern, Bern CH-3012 (Switzerland); Ivy-Ochs, S. [Institute for Particle Physics, ETH Zuerich, Zuerich CH-8093 (Switzerland); Akcar, N.; Schluechter, C. [Institute of Geological Sciences, University of Bern, Bern CH-3012 (Switzerland); Wieler, R. [Institute of Geochemistry and Petrology, ETH Zuerich, Zuerich CH-8092 (Switzerland)

    2013-01-15

    We present the improved performance of the modified in situ cosmogenic {sup 14}C extraction system at ETH Zuerich. Samples are now processed faster (2 days in total) and are measured with a high analytical precision of usually <2% using the gas ion source of the MICADAS AMS facility. Measurements of the PP-4 standard sample show a good reproducibility and consistency with published values. Procedural blanks are very low at currently {approx}4.0 Multiplication-Sign 10{sup 414}C atoms. Analyses of samples from a {approx}300 year old rock avalanche prove that we can successfully apply in situ{sup 14}C exposure dating to very young surfaces. Additionally, we present a modified calculation scheme for in situ{sup 14}C concentrations which differs from that used for conventional radiocarbon dating. This new approach explicitly accounts for the characteristics of in situ{sup 14}C production.

  15. Siberian population of the New Stone Age: mtDNA haplotype diversity in the ancient population from the Ust'-Ida I burial ground, dated 4020-3210 BC by 14C.

    Science.gov (United States)

    Naumova O, Y u; Rychkov S, Y u

    1998-03-01

    On the basis of analysis of mtDNA from skeletal remains, dated by 14C 4020-3210 BC, from the Ust'-Ida I Neolithic burial ground in Cis-Baikal area of Siberia, we obtained genetic characteristics of the ancient Mongoloid population. Using the 7 restriction enzymes for the analysis of site's polymorphism in 16,106-16,545 region of mtDNA, we studied the structure of the most frequent DNA haplotypes, and estimated the intrapopulational nucleotide diversity of the Neolithic population. Comparison of the Neolithic and modern indigeneous populations from Siberia, Mongolia and Ural showed, that the ancient Siberian population is one of the ancestors of the modern population of Siberia. From genetic distance, in the assumption of constant nucleotide substitution rate, we estimated the divergence time between the Neolithic and the modern Siberian population. This divergence time (5572 years ago) is conformed to the age of skeletal remains (5542-5652 years). With use of the 14C dates of the skeletal remains, nucleotide substitution rate in mtDNA was estimated as 1% sequence divergence for 8938-9115 years.

  16. Detecting human presence at the border of the Northeastern Italian Pre-Alps. 14C dating at Rio Secco cave as expression of the first Gravettian and the late mousterian in the Northern Adriatic Region.

    Science.gov (United States)

    Talamo, Sahra; Peresani, Marco; Romandini, Matteo; Duches, Rossella; Jéquier, Camille; Nannini, Nicola; Pastoors, Andreas; Picin, Andrea; Vaquero, Manuel; Weniger, Gerd-Christian; Hublin, Jean-Jacques

    2014-01-01

    In the northern Adriatic regions, which include the Venetian region and the Dalmatian coast, late Neanderthal settlements are recorded in few sites and even more ephemeral are remains of the Mid-Upper Palaeolithic occupations. A contribution to reconstruct the human presence during this time range has been produced from a recently investigated cave, Rio Secco, located in the northern Adriatic region at the foot of the Carnic Pre-Alps. Chronometric data make Rio Secco a key site in the context of recording occupation by late Neanderthals and regarding the diffusion of the Mid-Upper Palaeolithic culture in a particular district at the border of the alpine region. As for the Gravettian, its diffusion in Italy is a subject of on-going research and the aim of this paper is to provide new information on the timing of this process in Italy. In the southern end of the Peninsula the first occupation dates to around 28,000 14C BP, whereas our results on Gravettian layer range from 29,390 to 28,995 14C years BP. At the present state of knowledge, the emergence of the Gravettian in eastern Italy is contemporaneous with several sites in Central Europe and the chronological dates support the hypothesis that the Swabian Gravettian probably dispersed from eastern Austria.

  17. Detecting human presence at the border of the Northeastern Italian Pre-Alps. 14C dating at Rio Secco cave as expression of the first Gravettian and the late mousterian in the Northern Adriatic Region.

    Directory of Open Access Journals (Sweden)

    Sahra Talamo

    Full Text Available In the northern Adriatic regions, which include the Venetian region and the Dalmatian coast, late Neanderthal settlements are recorded in few sites and even more ephemeral are remains of the Mid-Upper Palaeolithic occupations. A contribution to reconstruct the human presence during this time range has been produced from a recently investigated cave, Rio Secco, located in the northern Adriatic region at the foot of the Carnic Pre-Alps. Chronometric data make Rio Secco a key site in the context of recording occupation by late Neanderthals and regarding the diffusion of the Mid-Upper Palaeolithic culture in a particular district at the border of the alpine region. As for the Gravettian, its diffusion in Italy is a subject of on-going research and the aim of this paper is to provide new information on the timing of this process in Italy. In the southern end of the Peninsula the first occupation dates to around 28,000 14C BP, whereas our results on Gravettian layer range from 29,390 to 28,995 14C years BP. At the present state of knowledge, the emergence of the Gravettian in eastern Italy is contemporaneous with several sites in Central Europe and the chronological dates support the hypothesis that the Swabian Gravettian probably dispersed from eastern Austria.

  18. AMS radiocarbon dating of wood trunks in the pumiceous deposits of the Kikai-Akahoya eruption in Yakushima Island, SW Japan

    Science.gov (United States)

    Okuno, Mitsuru; Nakamura, Toshio; Geshi, Nobuo; Kimura, Katsuhiko; Saito-Kokubu, Yoko; Kobayashi, Tetsuo

    2013-01-01

    Radiocarbon dating using accelerator mass spectrometry (AMS) was performed on numerous wood trunks from pumiceous deposits along the Nagata, Isso and Miyanoura rivers on the northern side of Yakushima Island, 60 km south of Kyushu Island. The obtained 14C dates were around 6.5 ka BP, which, in combination with the geological characteristics of the pumiceous deposits indicates that these specimens were buried during the Kikai-Akahoya (K-Ah) eruption from the Kikai caldera. However, the fact that they are not charred suggests that the origin of these deposits are not pyroclastic flows. Fourteen taxa (Pinus subgen. Diploxylon, Tsuga, Cryptomeria, Chamaecyparis, Myrica, Castanea, Castanopsis, Quercus subgen. Cyclobalanopsis, Trochodendron, Phellodendron, Lagerstroemia, Rhododendron, Myrsine and Symplocos) were identified through anatomical characteristics. This is the first discovery of forest species on the Yakushima Island before the devastating eruption.

  19. AMS radiocarbon dating of wood trunks in the pumiceous deposits of the Kikai-Akahoya eruption in Yakushima Island, SW Japan

    Energy Technology Data Exchange (ETDEWEB)

    Okuno, Mitsuru, E-mail: okuno@fukuoka-u.ac.jp [Department of Earth System Science, Faculty of Science, Fukuoka University, 814-0180 Fukuoka (Japan); AIG Collaborative Research Institute for International Study on Eruptive History and Informatics, Fukuoka University, 814-0180 Fukuoka (Japan); Nakamura, Toshio [Center for Chronological Research, Nagoya University, 464-8602 Nagoya (Japan); Geshi, Nobuo [Geological Survey of Japan, National Institute of Advanced Science and Technology, 305-8567 Tsukuba (Japan); Kimura, Katsuhiko [Division of Environment System Management, Faculty of Symbiotic System Science, Fukushima University, 960-1296 Fukushima (Japan); Saito-Kokubu, Yoko [Tono Geoscience Center, Japan Atomic Energy Agency (JAEA), 959-31 Jorinji, Toki, Gifu 509-5102 (Japan); Kobayashi, Tetsuo [Department of Earth and Environmental Sciences, Graduate School of Science and Engineering, Kagoshima University, 890-0065 Kagoshima (Japan)

    2013-01-15

    Radiocarbon dating using accelerator mass spectrometry (AMS) was performed on numerous wood trunks from pumiceous deposits along the Nagata, Isso and Miyanoura rivers on the northern side of Yakushima Island, 60 km south of Kyushu Island. The obtained {sup 14}C dates were around 6.5 ka BP, which, in combination with the geological characteristics of the pumiceous deposits indicates that these specimens were buried during the Kikai-Akahoya (K-Ah) eruption from the Kikai caldera. However, the fact that they are not charred suggests that the origin of these deposits are not pyroclastic flows. Fourteen taxa (Pinus subgen. Diploxylon, Tsuga, Cryptomeria, Chamaecyparis, Myrica, Castanea, Castanopsis, Quercus subgen. Cyclobalanopsis, Trochodendron, Phellodendron, Lagerstroemia, Rhododendron, Myrsine and Symplocos) were identified through anatomical characteristics. This is the first discovery of forest species on the Yakushima Island before the devastating eruption.

  20. Forensic applications of {sup 14}C at CIRCE

    Energy Technology Data Exchange (ETDEWEB)

    Marzaioli, F., E-mail: fabio.marzaioli@unina2.it [CIRCE, Dipartimento di Scienze Ambientali, Seconda Universita degli Studi di Napoli and INNOVA, Via Vivaldi 43, 81100 Caserta (Italy); Fiumano, V., E-mail: vittoriofiumano85@libero.it [CIRCE, Dipartimento di Scienze della Vita, Seconda Universita degli Studi di Napoli and INNOVA, Via Vivaldi 43, 81100 Caserta (Italy); Capano, M., E-mail: manuela.capano@unina2.it [CIRCE, Dipartimento di Studio delle Componenti Culturali del Territorio, Seconda Universita degli Studi di Napoli and INNOVA, Piazza S. Francesco, 81055 Santa Maria Capua Vetere, Caserta (Italy); Passariello, I., E-mail: isabella.passariello@unina2.it [CIRCE, Dipartimento di Scienze Ambientali, Seconda Universita degli Studi di Napoli and INNOVA, Via Vivaldi 43, 81100 Caserta (Italy); Cesare, N.De., E-mail: nicola.decesare@unina2.it [CIRCE, Dipartimento di Scienze della Vita, Seconda Universita degli Studi di Napoli and INNOVA, Via Vivaldi 43, 81100 Caserta (Italy); Terrasi, F., E-mail: filippo.terrasi@unina2.it [CIRCE, Dipartimento di Scienze Ambientali, Seconda Universita degli Studi di Napoli and INNOVA, Via Vivaldi 43, 81100 Caserta (Italy)

    2011-12-15

    The decreasing trend of the radiocarbon pulse produced during the atmospheric tests of nuclear weapons (bomb-carbon) coupled with high sensitivity accelerator mass spectrometry (AMS) measurements, drastically increased the precision of radiocarbon age determinations since the second part of the sixties, allowing the application of radiocarbon AMS to a wide range of studies previously not directly involving conventional radiocarbon dating (i.e. food authenticity, forensic, biochemistry). In the framework of authenticity evaluation of artworks, high precision radiocarbon ({sup 14}C) AMS measurements ({Delta}R/R < 0.3%) reduce the conventional uncertainty of the dating to few decades, allowing precise age estimation of materials containing carbon (C). The Centre for Isotopic Research on Cultural and Environmental heritage (CIRCE) during its activity on AMS {sup 14}C dating achieved high precision measurements opening the opportunity to these kinds of applications. This paper presents the main results obtained from radiocarbon measurements on a set of bone samples analyzed for the determination of the post-mortem interval in the framework of an unsolved case investigated by the Rome prosecutor office. The chronological characterization of the wooden support of the 'Acerenza portrait' is also presented with the aim to evaluate its age and to further investigate the possibility to attribute this artwork to Leonardo da Vinci. Bomb-{sup 14}C dating on the lipid and collagen fractions of bones allows the evaluation of the year of the death of the individuals by means of ad hoc calibration data sheet with the typical few years precision and difference between collagen apparent age and the year of death appeared in agreement with the age of one individual estimated by dating of tooth collagen. Conventional radiocarbon dating on both wood and wood extracted cellulose leads to an estimation of the portrait wood board age (2{sigma}) of 1459-1524 AD (57% relative

  1. Reviewing the Mid-First Millennium BC {sup 14}C 'warp' using {sup 14}C/bristlecone pine data

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, R.E., E-mail: retaylor@ucr.edu [Department of Anthropology, University of California, Riverside, Riverside, CA (United States); Cotsen Institute of Archaeology, University of California, Los Angeles, CA (United States); Keck Carbon Cycle Accelerator Mass Spectrometry Laboratory, University of California, Irvine, CA (United States); Southon, John [Keck Carbon Cycle Accelerator Mass Spectrometry Laboratory, University of California, Irvine, CA (United States)

    2013-01-15

    AMS-based {sup 14}C measurements have been obtained on 53 dendrochronologically-dated Bristlecone pine (Pinus longaeva) wood samples in decadal increments spanning 2300-2750 cal BP with particular interest focused on the decades centered on 2405 cal BP and 2625 cal BP. In general, there is overall agreement with the current IntCal04/09 consensus calibration curve for this period. For the 2400-2410 cal BP interval, our Bristlecone-based {sup 14}C value is consistent with the {sup 14}C value obtained by Belfast on Irish oak for that decade but not on German oak values obtained by Seattle. Our {sup 14}C value for the 2620-2630 cal BP interval is consistent with the German oak (Heidelberg)-based {sup 14}C decadal value. The {sup 10}Be-based reconstruction of {sup 14}C variations over the 2620-2630 cal BP interval also supports the Heidelberg data although clearly additional clarifications are required before the current tree ring-based {sup 14}C and ice core-based {sup 10}Be data for this interval can be accurately interpreted and valid inferences obtained.

  2. How accurate is the 14C method

    International Nuclear Information System (INIS)

    Nydal, R.

    1979-01-01

    Radiocarbon daters have in recent years focussed their interest on accuracy and reliability of 14 C dates. The use of dates for resolving fine chronological structures that are not dateable otherwise has stressed this point. The total uncertainty in dating an event is composed of errors relating to dating of the sample, i.e. uncertainty in measured quantities, deviations from assumed content of 14 C in material when alive; and errors related to quality of sample material, i.e. contamination from carbon of different age, diffuse context between sample and event. Statistical variability in counting of 14 C activity gives the most important contribution to measurement uncertainty - increasing with age and shortage of sample material. Corrections for isotopic fractionation and reservoir effects must be performed, and - most important when dates are compared with historical ages - the dendrochronological calibration will correct for past variations in the atmospheric 14 C content. Future improvement of dating precision can however only be obtained by the combined efforts of both daters and submitters of samples, thus minimizing errors related to selection and handling of sample material as well as those related to the 14 C method and measurements. (Auth.)

  3. Old ages of two historical Romanian trees assessed by AMS radiocarbon dating

    International Nuclear Information System (INIS)

    Patrut, Adrian; Reden, Karl F. von; Lowy, Daniel A.; Patrut, Roxana T.; Lucian Vaida, D.; Margineanu, Dragos

    2013-01-01

    Two large Romanian poplars are considered to be associated with significant historical events of the past. In order to verify these claims, wood samples collected from the broken trunks of the two poplars were radiocarbon dated by AMS. The oldest radiocarbon dates were found to be 275 ± 20 bp for the black poplar of Mocod and 316 ± 22 bp for the gray poplar of Rafaila. These values correspond to calibrated ages of 365 ± 10 and 465 ± 25 years, respectively. The dating results indicate old ages for the two trees, i.e., 455 years for the Mocod poplar and 560 years for the Rafaila poplar. Such age values validate historical information on the two large Romanian trees.

  4. Old ages of two historical Romanian trees assessed by AMS radiocarbon dating

    Energy Technology Data Exchange (ETDEWEB)

    Patrut, Adrian, E-mail: apatrut@gmail.com [Babes-Bolyai University, Department of Chemistry, Arany Janos 11, 400028 Cluj-Napoca (Romania); Reden, Karl F. von [Woods Hole Oceanographic Institution, Department of Geology and Geophysics, NOSAMS Facility, 360 Woods Hole Rd., Mailstop 8, Woods Hole, MA 02543 (United States); Lowy, Daniel A. [FlexEl, LLC, 387 Technology Drive, College Park, MD 20742 (United States); Patrut, Roxana T. [Babes-Bolyai University, Department of Biology and Geology, Gh. Bilascu 44, 400015 Cluj-Napoca (Romania); Lucian Vaida, D. [Museum of Border Regiment Nasaud, Granicerilor 19, 425200 Nasaud (Romania); Margineanu, Dragos [Babes-Bolyai University, Department of Chemistry, Arany Janos 11, 400028 Cluj-Napoca (Romania)

    2013-01-15

    Two large Romanian poplars are considered to be associated with significant historical events of the past. In order to verify these claims, wood samples collected from the broken trunks of the two poplars were radiocarbon dated by AMS. The oldest radiocarbon dates were found to be 275 {+-} 20 bp for the black poplar of Mocod and 316 {+-} 22 bp for the gray poplar of Rafaila. These values correspond to calibrated ages of 365 {+-} 10 and 465 {+-} 25 years, respectively. The dating results indicate old ages for the two trees, i.e., 455 years for the Mocod poplar and 560 years for the Rafaila poplar. Such age values validate historical information on the two large Romanian trees.

  5. A combined PIXE-PIGE approach for the assessment of the diagenetic state of cremated bones submitted to AMS radiocarbon dating

    Energy Technology Data Exchange (ETDEWEB)

    Quarta, Gianluca, E-mail: gianluca.quarta@unisalento.it [CEDAD-Department of Engineering for Innovation, University of Salento, via per Monteroni, 73100 Lecce (Italy); Calcagnile, Lucio; D' Elia, Marisa; Maruccio, Lucio; Gaballo, Valentina; Caramia, Annalisa [CEDAD-Department of Engineering for Innovation, University of Salento, via per Monteroni, 73100 Lecce (Italy)

    2013-01-15

    Bone samples from a Bronze age necropolis in Northern Italy, exposed to different combustion temperatures, were submitted to XRD (X-ray Diffraction), PIXE (Particle Induced X-ray Emission) and PIGE (Particle Induced Gamma Ray Emission) analyses in order to obtain information about their diagenetic state. Structural carbonate was then extracted by acid hydrolysis and used for {sup 14}C-AMS (Accelerator Mass Spectrometry) dating. These analytical techniques permitted the study of the effects of the combustion temperature on the crystallinity of the bone apatite and on its elemental chemical composition in terms of major, minor and trace elements. The results indicate that combustion at temperatures above {approx}700 Degree-Sign C induces changes in the bone crystalline structure, reducing the diagenetic uptake of elements from the burial environment.

  6. A combined PIXE-PIGE approach for the assessment of the diagenetic state of cremated bones submitted to AMS radiocarbon dating

    Science.gov (United States)

    Quarta, Gianluca; Calcagnile, Lucio; D'Elia, Marisa; Maruccio, Lucio; Gaballo, Valentina; Caramia, Annalisa

    2013-01-01

    Bone samples from a Bronze age necropolis in Northern Italy, exposed to different combustion temperatures, were submitted to XRD (X-ray Diffraction), PIXE (Particle Induced X-ray Emission) and PIGE (Particle Induced Gamma Ray Emission) analyses in order to obtain information about their diagenetic state. Structural carbonate was then extracted by acid hydrolysis and used for 14C-AMS (Accelerator Mass Spectrometry) dating. These analytical techniques permitted the study of the effects of the combustion temperature on the crystallinity of the bone apatite and on its elemental chemical composition in terms of major, minor and trace elements. The results indicate that combustion at temperatures above ∼700 °C induces changes in the bone crystalline structure, reducing the diagenetic uptake of elements from the burial environment.

  7. Development of a sample preparation system for AMS radiocarbon dating at CRICH, Korea

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Myung-Jin; Lee, Byeong-Cheol; Lim, Eun-Soo [Cultural Research Institute of Chungcheong Heritage, Gongju (Korea, Republic of); Hong, Duk-Geun [Kangwon National University, Chuncheon (Korea, Republic of); Park, Soon-Bal [Chungnam National University, Daejeon (Korea, Republic of); Youn, Min-Young [Seoul National University, Seoul (Korea, Republic of)

    2010-01-15

    We developed a sample preparation system for radiocarbon dating by using AMS measurement at Cultural Research Institute of Chungcheong Heritage, Korea. From the investigation of the reduction process, the optimum graphitization temperature was chosen as 625 .deg. C. Using Aldrich graphite powder of 0.75 {+-} 0.023 pMC, the background value of our preparation system was controlled at a low level. The robustness against chemical treatment and contamination was also observed from samples of Oxalic acid II and IAEA-C4. The resultant values, 134.04 {+-} 0.99 pMC and 0.38 {+-} 0.043 pMC, were in good agreement with the consensus values. Based on comparison, our conventional ages agreed very well with those of Beta Analytic Co. and SNU-AMS. No memory effect existed in the preparation system. Therefore, we concluded that the sample preparation system was operated in a stable manner and that the basic radiocarbon dating procedures were completely verified.

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

    International Nuclear Information System (INIS)

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

    2005-01-01

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

  9. 14C uncovers the past

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    Radio-carbon dating, a method of dating prehistoric remains that has been developed since the Second World War, is based on the fact that all organic matter contains a radioactive isotope of carbon - 14 C- which, because it decays at a fixed rate, gives a good indication of the age of the substance. The CSIR's National Physical Research Laboratory entered the field of radio-carbon dating in 1967, when the Nature Isotopes Division was established. The division has become a world centre of excellence and much has been done to clear up the chronology of southern African prehistory. It has been found, for instance, that anatomically modern man appeared in southern Africa some 40000 years earlier than in Europe, and that the Zimbabwe ruins were built mainly around the year 1350 AD. The radio-carbon method can also be used to determine the age and flow rate of underground water and the rate at which tracer gases dissolve in the oceans, i.e. the efficiency with which the oceans cleanse the atmosphere from pollutants

  10. Ion beam analysis and AMS dating of the silver coin hoard of Preuschdorf (Alsace, France)

    Science.gov (United States)

    Beck, Lucile; Alloin, Elise; Vigneron, Anaïs; Caffy, Ingrid; Klein, Ulrich

    2017-09-01

    The hoard of Preuschdorf is a monetary deposit discovered in Alsace (France) in 2005. This find was composed of 7327 silver-copper coins. They seem to have been struck over more than one century, between the end of the 15th and the beginning of the 17th century. This hoard is an exceptional find composed of a large quantity of coins from various periods, areas and contexts. It is also remarkable by the presence of counterfeit coins. IBA was used to analyze the silver content of the official coins by combining PIXE and RBS. The fineness was found to be between 20 and 42% according to the mint place and an unexpected subdivision of the values has been revealed. For the counterfeit coins, the analyses were able to bring to light different elaboration processes: amalgam silvering with two various contents of mercury and application of a thin layer of pure silver. Finally, linen fibers attached to the coins have been dated by AMS radiocarbon dating. The radiocarbon calibrated dates perfectly match with the chronological range given by the coins.

  11. AMS Radiocarbon Dating of Large Za Baobabs (Adansonia za) of Madagascar.

    Science.gov (United States)

    Patrut, Adrian; Patrut, Roxana T; Danthu, Pascal; Leong Pock-Tsy, Jean-Michel; Rakosy, Laszlo; Lowy, Daniel A; von Reden, Karl F

    2016-01-01

    The article reports the radiocarbon investigation of Anzapalivoro, the largest za baobab (Adansonia za) specimen of Madagascar and of another za, namely the Big cistern baobab. Several wood samples collected from the large inner cavity and from the outer part/exterior of the tree were investigated by AMS (accelerator mass spectrometry) radiocarbon dating. For samples collected from the cavity walls, the age values increase with the distance into the wood up to a point of maximum age, after which the values decrease toward the outer part. This anomaly of age sequences indicates that the inner cavity of Anzapalivoro is a false cavity, practically an empty space between several fused stems disposed in a ring-shaped structure. The radiocarbon date of the oldest sample was 780 ± 30 bp, which corresponds to a calibrated age of around 735 yr. Dating results indicate that Anzapalivoro has a closed ring-shaped structure, which consists of 5 fused stems that close a false cavity. The oldest part of the biggest za baobab has a calculated age of 900 years. We also disclose results of the investigation of a second za baobab, the Big cistern baobab, which was hollowed out for water storage. This specimen, which consists of 4 fused stems, was found to be around 260 years old.

  12. AMS Radiocarbon Dating of Large Za Baobabs (Adansonia za of Madagascar.

    Directory of Open Access Journals (Sweden)

    Adrian Patrut

    Full Text Available The article reports the radiocarbon investigation of Anzapalivoro, the largest za baobab (Adansonia za specimen of Madagascar and of another za, namely the Big cistern baobab. Several wood samples collected from the large inner cavity and from the outer part/exterior of the tree were investigated by AMS (accelerator mass spectrometry radiocarbon dating. For samples collected from the cavity walls, the age values increase with the distance into the wood up to a point of maximum age, after which the values decrease toward the outer part. This anomaly of age sequences indicates that the inner cavity of Anzapalivoro is a false cavity, practically an empty space between several fused stems disposed in a ring-shaped structure. The radiocarbon date of the oldest sample was 780 ± 30 bp, which corresponds to a calibrated age of around 735 yr. Dating results indicate that Anzapalivoro has a closed ring-shaped structure, which consists of 5 fused stems that close a false cavity. The oldest part of the biggest za baobab has a calculated age of 900 years. We also disclose results of the investigation of a second za baobab, the Big cistern baobab, which was hollowed out for water storage. This specimen, which consists of 4 fused stems, was found to be around 260 years old.

  13. AMS radiocarbon dating of very large Grandidier’s baobabs (Adansonia grandidieri)

    Energy Technology Data Exchange (ETDEWEB)

    Patrut, Adrian [Babeş-Bolyai University, Faculty of Chemistry, Cluj-Napoca (Romania); Reden, Karl F. von [NOSAMS Facility, Dept. of Geology & Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA (United States); Danthu, Pascal [Cirad, UPR BSEF, Montpellier (France); DP Forêt et Biodiversité, Antananarivo (Madagascar); Leong Pock-Tsy, Jean-Michel [DP Forêt et Biodiversité, Antananarivo (Madagascar); Rakosy, Laszlo; Patrut, Roxana T. [Babeş-Bolyai University, Faculty of Biology and Geology, Cluj-Napoca (Romania); Lowy, Daniel A. [Nova University, Alexandria Campus, Alexandria, VA (United States); Margineanu, Dragos [Babeş-Bolyai University, Faculty of Chemistry, Cluj-Napoca (Romania)

    2015-10-15

    The article reports the AMS radiocarbon investigation of the two largest known Adansonia grandidieri specimens. The two baobabs, which are named Tsitakakoike and Pregnant baobab, are located in Southwestern Madagascar, near Andombiro. A third specimen from this area, the House baobab, was also investigated. According to measurements, Tsitakakoike is the biggest individual above ground level of all Adansonia species. The House baobab was selected for its exposed structure, which is identical to the closed ring-shaped structure with false cavities identified by us in large and old Adansonia digitata specimens. According to our research, Tsitakakoike and the Pregnant baobab have multi-stemmed cylindrical trunks which are mainly hollow; the two very large baobabs also possess a ring-shaped structure. The radiocarbon dates of the oldest wood samples collected from the large trunks were 1274 ± 20 BP for Tsitakakoike and 930 ± 20 BP for the Pregnant baobab. According to their original positions and to the architectures of the two A. grandidieri, the ages of Tsitakakoike and Pregnant baobab would be between 1300 and 1500 years. Therefore, A. grandidieri becomes the third Adansonia species with individuals that can live over 1000 years, according to accurate dating results.

  14. AMS radiocarbon analyses from Lake Baikal, Siberia: Challenges of dating sediments from a large, oligotrophic lake

    Science.gov (United States)

    Colman, Steven M.; Jones, Glenn A.; Rubin, M.; King, J.W.; Peck, J.A.; Orem, W.H.

    1996-01-01

    A suite of 146 new accelerator-mass spectrometer (AMS) radiocarbon ages provides the first reliable chronology for late Quaternary sediments in Lake Baikal. In this large, highly oligotrophic lake, biogenic and authigenic carbonate are absent, and plant macrofossils are extremely rare. Total organic carbon is therefore the primary material available for dating. Several problems are associated with the TOC ages. One is the mixture of carbon sources in TOC, not all of which are syndepositional in age. This problem manifests itself in apparent ages for the sediment surface that are greater than zero. However, because most of the organic carbon in Lake Baikal sediments is algal (autochthonous) in origin, this effect is limited to about 1000+500 years, which can be corrected, at least for young deposits. The other major problem with dating Lake Baikal sediments is the very low carbon contents of glacial-age deposits, which makes them extremely susceptible to contamination with modern carbon. This problem can be minimized by careful sampling and handling procedures. The ages show almost an order of magnitude difference in sediment-accumulation rates among different sedimentary environments in Lake Baikal, from about 0.04 mm/year on isolated banks such as Academician Ridge, to nearly 0.3 mm/year in the turbidite depositional areas beneath the deep basin floors, such as the Central Basin. The new AMS ages clearly indicate that the dramatic increase in diatom productivity in the lake, as evidenced by increases in biogenic silica and organic carbon, began about 13 ka, in contrast to previous estimates of 7 ka for the age of this transition. Holocene net sedimentation rates may be less than, equal to, or greater than those in the late Pleistocene, depending on the site. This variability reflects the balance between variable terrigenous sedimentation and increased biogenic sedimentation during interglaciations. The ages reported here, and the temporal and spatial variation in

  15. Uptake of [14C]triadimenol via grain and root after seed treatment of winter barley with a flowable seed dressing: Influence of soil moisture and sowing date on the distribution of radioactivity and active ingredient content in plant and soil

    International Nuclear Information System (INIS)

    Schneider, M.

    1988-12-01

    Winter barley seed of the 'Vogelsander Gold' variety was shown in a total of 7 lysimeters after seed treatment with [benzene ring-U- 14 C]triadimenol in the formulation as [ 14 C]Baytan 075 FS and [ 14 C]Baytan 25 DS at an early (September) and a late date (October). After both dates of sowing, the FS-treated winter barley developed under 3 different soil moisture conditions. The radioactivity and active ingredient contents in plants and soil were recorded until tillering as a function of low, high and natural precipitation after sowing. Details on the uptake of radioactivity via grain and roots were quantitatively and qualitatively studied in two further lysimeters, a pot experiment as well as experiments in the growth chamber. The results are presented and discussed in detail. (orig./MG) [de

  16. Time range for accumulation of shell middens from Higashimyo (western Japan) and Kimhae (southern Korea) by AMS radiocarbon dating

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Toshio, E-mail: nakamura@nendai.nagoya-u.ac.jp [Center for Chronological Research, Nagoya University, Chikusa, Nagoya 464-8602 (Japan); Matsui, Akira [National Research Institute for Cultural Properties, Nara, Nijyo-cho, Nara 630-8577 (Japan); Nishida, Iwao; Nakano, Mitsuru [Saga-City Board of Education, Sakae-machi, Saga 840-8501 (Japan); Omori, Takayuki [University Museum, University of Tokyo, Hongo 7-3-1, Bunkyo, Tokyo 113-0033 (Japan)

    2013-01-15

    Numerous large and small shell middens have been reported throughout the world. An interesting question is when the huge and thick shell middens were formed, and how many years were required to build up the whole midden. Shell middens contain not only shell fragments but also organic substances such as bones, nuts, acorn, and plant residues, which are suitable substances with which to establish {sup 14}C chronology of the middens. We have conducted {sup 14}C dating on terrestrial and marine materials collected from two lowland shell middens, the Higashimyo site in Japan (the Earliest Jomon period) and the Kimhae site in Korea (the Proto-Three Kingdom period), to establish high precision {sup 14}C chronologies and determine the time required for shell accumulation. According to Bayesian analysis of {sup 14}C ages from terrestrial samples, accumulation of Midden No. 1 at Higashimyo (altitude from -1.1 to -2.3 m a.s.l., {Delta}d = 1.2 m) started at around 8050-7950 cal BP and ended at 7950-7750 cal BP, lasting for ca. 100 cal yr, while accumulation of Midden No. 2 (altitude from -0.5 to -2.0 m a.s.l., {Delta}d = 1.5 m) started at around 8050-7800 cal BP and ended at 7800-7650 cal BP, lasting for ca. 200 cal yr. Thus the Midden No. 1 was abandoned a bit earlier than Midden No. 2, but the time range for sediment accumulation overlaps each other. Accumulation at the Kimhae shell midden (altitude from 5 to 14 m a.s.l., {Delta}d = 9 m) started at around the middle of the 1st C cal BC and ended at around the middle of the 3rd C cal AD, lasting for ca. 250 to 300 cal yr.

  17. Radiocarbon dating of a Japanese ancient document 'Minamoto no Yoritomo Sodehan Migyosho' by AMS

    International Nuclear Information System (INIS)

    Oda, H.; Nakaura, T.; Akiyama, M.

    2005-01-01

    In this study, radiocarbon age of a Japanese ancient document 'Minamoto no Yoritomo Sodehan Migyosho' was measured by AMS. The purpose of this study is to judge whether the document is genuine or not. The document descended to the Matsugi family which had controlled the craftsmen of metal casting. The document has a description of the written age, AD1189. The content of the document is about the formal recognition of their authority over the craftsmen by Minamoto no Yoritomo who established the first military government in AD1192. This document is written on a slightly-blackish-paper sheet called Shukushi. Shukushi paper sheets had been commonly used for the official documents of the Emperor. Therefore, if the document was really issued by Minamoto no Yoritomo, it can be a sole example as the document of warrior class among the extant Shukushi paper. The paleographical views, however, suggested that the document may be a counterfeit written in several centuries later. Japanese paper fragment is a suitable sample for radiocarbon dating because there is little discrepancy between the calibrated radiocarbon age and the written age. The calibrated radiocarbon age of 'Minamoto no Yoritomo Sodehan Migyosho' indicated the 16th century or the first half of the 17th century. This age corresponds to the period when the ancestor of Matsugi family appeared in Japanese history. This result shows that the document was forged in the Warring State Period for the legitimacy of their control over the craftsmen. The Shukusi used for the counterfeit document of warrior class is the outcome of the forger's misunderstanding that Shukushi paper should be used for the important documents.

  18. Forgery at the Snite Museum of Art? Improving AMS Radiocarbon Dating at the University of Notre Dame

    Science.gov (United States)

    Troyer, Laura; Bagwell, Connor; Anderson, Tyler; Clark, Adam; Nelson, Austin; Skulski, Michael; Collon, Philippe

    2017-09-01

    The Snite Museum of Art recently obtained several donations of artifacts. Five of the pieces lack sufficient background information to prove authenticity and require further analysis to positively determine the artwork's age. One method to determine the artwork's age is radiocarbon dating via Accelerator Mass Spectrometry (AMS) performed at the University of Notre Dame's Nuclear Science Laboratory. Samples are prepared by combustion of a small amount of material and subsequent reduction to carbon into an iron powder matrix (graphitization). The graphitization procedure affects the maximum measurement rate, and a poor graphitization can be detrimental to the AMS measurement of the sample. Previous graphitization procedures resulted in a particle current too low or inconsistent to optimize AMS measurements. Thus, there was a desire to design and refine the graphitization system. The finalized process yielded physically darker samples and increased sample currents by two orders of magnitude. Additionally, the first testing of the samples was successful, yet analysis of the dates proved inconclusive. AMS measurements will be performed again to obtain better sampling statistics in the hopes of narrowing the reported date ranges. NSF and JINA-CEE.

  19. Accelerator mass spectrometry 14C determination in CO2 produced from laser decomposition of aragonite.

    Science.gov (United States)

    Rosenheim, Brad E; Thorrold, Simon R; Roberts, Mark L

    2008-11-01

    The determination of (14)C in aragonite (CaCO(3)) decomposed thermally to CO(2) using an yttrium-aluminum-garnet doped neodymium laser is reported. Laser decomposition accelerator mass spectrometry (LD-AMS) measurements reproduce AMS determinations of (14)C from the conventional reaction of aragonite with concentrated phosphoric acid. The lack of significant differences between these sets of measurements indicates that LD-AMS radiocarbon dating can overcome the significant fractionation that has been observed during stable isotope (C and O) laser decomposition analysis of different carbonate minerals. The laser regularly converted nearly 30% of material removed into CO(2) despite it being optimized for ablation, where laser energy breaks material apart rather than chemically altering it. These results illustrate promise for using laser decomposition on the front-end of AMS systems that directly measure CO(2) gas. The feasibility of such measurements depends on (1) the improvement of material removal and/or CO(2) generation efficiency of the laser decomposition system and (2) the ionization efficiency of AMS systems measuring continuously flowing CO(2).

  20. A reevaluation of the Pallett Creek earthquake chronology based on new AMS radiocarbon dates, San Andreas fault, California

    Science.gov (United States)

    Scharer, K.M.; Biasi, G.P.; Weldon, R.J.

    2011-01-01

    The Pallett Creek paleoseismic record occupies a keystone position in most attempts to develop rupture histories for the southern San Andreas fault. Previous estimates of earthquake ages at Pallett Creek were determined by decay counting radiocarbon methods. That method requires large samples which can lead to unaccounted sources of uncertainty in radiocarbon ages because of the heterogeneous composition of organic layers. In contrast, accelerator mass spectrometry (AMS) radiocarbon dates may be obtained from small samples that have known carbon sources and also allow for a more complete sampling of the section. We present 65 new AMS radiocarbon dates that span nine ground-rupturing earthquakes at Pallett Creek. Overall, the AMS dates are similar to and reveal no dramatic bias in the conventional dates. For many layers, however, individual charcoal samples were younger than the conventional dates, leading to earthquake ages that are overall slightly younger than previously reported. New earthquake ages are determined by Bayesian refinement of the layer ages based on stratigraphic ordering and sedimentological constraints. The new chronology is more regular than previously published records in large part due to new samples constraining the age of event R. The closed interval from event C to 1857 has a mean recurrence of 135years (?? = 83.2 years) and a quasiperiodic coefficient of variation (COV) of 0.61. We show that the new dates and resultant earthquake chronology have a stronger effect on COV than the specific membership of this long series and dating precision improvements from sedimentation rates. Copyright 2011 by the American Geophysical Union.

  1. Soil and vegetation dynamics in a forest-savannah boundary in Southern Amazon state during the holocene, using 14C dating and stable carbon isotopes of soil organic matter

    International Nuclear Information System (INIS)

    Vidotto, Elaine; Pessenda, Luiz Carlos Ruiz; Ribeiro, Adauto de Souza; Bendassolli, Jose Albertino

    2005-01-01

    This work presents a comparative study between organic soil horizons formed in depressions, distant ca. 500 meters from each sampling site, in a forest/savannah boundary in the Southern Amazon Basin. The influence of the paleovegetation and soil dynamics, based on carbon isotope ( 12 C, 13 C, 14 C) data of soil organic matter (SOM) was evaluated. The soils were classified as Dystropept (Cambissolo) and were considered as clayey. The total organic carbon contents decreased from the surface to deeper parts of the soils profiles. At deeper parts of the soil profiles in the savannah site, between 100 cm and 30 cm, the δ 13 C values characterized the influence of C 4 plants (around -18,0 per mille). From about 20 cm to the surface the δ 13 C values characterized the mixture of C 3 and C 4 plants. The soil δ 13 C values in the forest site ranged from -25,0 per mille at deeper parts of the profile to -26,0 per mille in the surface, characterizing the dominance of C 3 plants in this location. 13 C and 14 C data from soil samples indicated a predominance of C 3 plants in the early Holocene. From ca. 7000 to 3000 years BP the influence of C 4 plants increased, characterizing a savannah expansion probably related to a drier climate in the region. Since 3000 years 14 C BP, the carbon isotope data suggest the forest expansion, probably due to a return to wetter climate. 14 C data in the 40-50 cm and 100 cm soil depth were contemporary, showing no difference on the soil organic matter deposition in the savannah and in the forest locations. (author)

  2. 14C accelerator mass spectrometry - applications in archaeology, biomedicine and in the atmospheric sciences

    International Nuclear Information System (INIS)

    Rom, W.

    1990-03-01

    Accelerator mass spectrometry (AMS) is superior to all other analytical techniques in its detection sensitivity of radiocarbon ( 14 C). It has therefore influenced or even laid down the foundations for applications in many fields of science. In the current work, various applications of 14 C AMS are presented through published articles for which the measurements were performed at the Vienna Environmental Research Accelerator (VERA). These articles are embedded into an in-depth discussion about characteristic features of the respective fields, emphasizing the broad range of issues which need to be considered in interdisciplinary research. In archaeology new 14 C dates on equipment of the Iceman ('Oetzi'), the world's oldest intact mummy, show reasonable agreement with dates previously obtained on the Iceman himself (3360-3100 BC). However, several botanical remains from the finding place clearly belong to other time periods, indicating that the discovery site of Oetzi has been used as a mountain pass 1500 yr earlier and also 2000 yr later. Dating on spruce logs from the world's oldest salt mines at Hallstatt, Austria provide evidence that salt mining started 1-2 centuries earlier than previously supposed, i.e. in the 14th to the 13th century BC. Recently, Bayesian mathematics is a frequently used tool in calibrating radiocarbon data. So-called vague or non-informative priors employed in this method may cause severe problems as shown by extensive computer simulations. In biomedicine problems in toxicology and in forensic medicine were investigated. Heterocyclic amines (HAs) are probably the epidemiologically most relevant class of mutagenic and carcinogenic substances since they are produced naturally in cooking protein-rich food. A study of 14 C labeled HAs (MeIQx and PhIP) in rodents and humans, one of the first studies using 14 C-labeled mutagens also in healthy human volunteers, severely calls in question the validity of animal models for assessing heterocyclic

  3. Progress on multi-nuclide AMS of JAEA-AMS-TONO

    Science.gov (United States)

    Saito-Kokubu, Yoko; Matsubara, Akihiro; Miyake, Masayasu; Nishizawa, Akimitsu; Ohwaki, Yoshio; Nishio, Tomohiro; Sanada, Katsuki; Hanaki, Tatsumi

    2015-10-01

    The JAEA-AMS-TONO (Japan Atomic Energy Agency's Accelerator Mass Spectrometer established at the Tono Geoscience Center) facility has been used for the dating of geological samples. The AMS system is versatile, based on a 5 MV tandem Pelletron-type accelerator. Since its establishment in 1997, the AMS system has been used for measurement of carbon-14 (14C) mainly for 14C dating studies in neotectonics and hydrogeology, in support of JAEA's research on geosphere stability applicable to the long-term isolation of high-level radioactive waste. Results of the measurement of 14C in soils and plants has been applied to the dating of fault activity and volcanism. Development of beryllium-10 (10Be) and aluminum-26 (26Al) AMS systems are now underway to enhance the capability of the multi-nuclide AMS in studies of dating by cosmogenic nuclides. The 10Be-AMS system has already been used for routine measurements in applied studies and improvements of the measurement technique have been made. Now we plan to fine tune the system and perform test measurements to develop the 26Al-AMS system.

  4. Progress on multi-nuclide AMS of JAEA-AMS-TONO

    Energy Technology Data Exchange (ETDEWEB)

    Saito-Kokubu, Yoko, E-mail: kokubu.yoko@jaea.go.jp [Japan Atomic Energy Agency, Toki, Gifu 509-5102 (Japan); Matsubara, Akihiro [Japan Atomic Energy Agency, Toki, Gifu 509-5102 (Japan); Miyake, Masayasu; Nishizawa, Akimitsu; Ohwaki, Yoshio; Nishio, Tomohiro; Sanada, Katsuki [Pesco Corp., Ltd., Toki, Gifu 509-5123 (Japan); Hanaki, Tatsumi [Japan Atomic Energy Agency, Toki, Gifu 509-5102 (Japan)

    2015-10-15

    The JAEA-AMS-TONO (Japan Atomic Energy Agency’s Accelerator Mass Spectrometer established at the Tono Geoscience Center) facility has been used for the dating of geological samples. The AMS system is versatile, based on a 5 MV tandem Pelletron-type accelerator. Since its establishment in 1997, the AMS system has been used for measurement of carbon-14 ({sup 14}C) mainly for {sup 14}C dating studies in neotectonics and hydrogeology, in support of JAEA’s research on geosphere stability applicable to the long-term isolation of high-level radioactive waste. Results of the measurement of {sup 14}C in soils and plants has been applied to the dating of fault activity and volcanism. Development of beryllium-10 ({sup 10}Be) and aluminum-26 ({sup 26}Al) AMS systems are now underway to enhance the capability of the multi-nuclide AMS in studies of dating by cosmogenic nuclides. The {sup 10}Be-AMS system has already been used for routine measurements in applied studies and improvements of the measurement technique have been made. Now we plan to fine tune the system and perform test measurements to develop the {sup 26}Al-AMS system.

  5. Difficulty in assessing low 3H, 14C and 36Cl concentrations in old groundwaters and its implication for groundwater dating - ANDRA 2007/2008 drilling program (Meuse/Haute-Marne)

    International Nuclear Information System (INIS)

    Jean-Baptiste, P.; Fourre, E.; Dapoigny, A.; Michelot, J.L.; Massault, M.; Noret, A.; Rebeix, R.; Le Gal La Salle, C.; Aquilina, L.; Labasque, T.; Vinsot, A.

    2010-01-01

    -Rennes. Twenty five water samples were collected from drilling sites A, B, C, E, F. At each site, one drill hole was dedicated to the study of the Oxfordian aquifer, a second to the Dogger and a third to the COx layer. An additional borehole was drilled to the Trias formation at site C. Two sampling devices were used and tested for sampling single water venues, including a specially design bottle sampler allowing to take samples at a specific depth in the water column, and a 'diapo' system that can pump water from a specified depth horizon. In parallel, 'global' water samples were collected using a submersible pump that samples the entire water column. Samples for radiocarbon analyses were collected in stainless-steel flow through vessels, without any contact with the atmosphere, while 3 H samples were collected in glass bottles. In order to obtain the best possible results, samples were taken on three different occasions, (i) during the drilling operations, (ii) after a short pumping period (a few days) and (iii) after a 'long-term' pumping (on the order of 10 days). Further constraints were borehole chemical logging that involved injection of foreign shallow aquifer waters ( 14 C and 3 H rich) along with NaCl or NaBr tracers. The tritium versus radiocarbon diagram shows that a significant number of samples are above the detection limit. The good agreement between 14 C and 3 H results, and the non-negligible CFC content of those samples, allows us to discard any analytical problems. For groundwaters showing anomalous 3 H and 14 C levels, an explanation can easily be found. In particular, the Oxfordian groundwaters from site E are known to be contaminated by young waters, likely due to leakage problems with the drill casing (these waters also show anomalous geochemical and helium concentrations). Samples from boreholes that underwent tracing also show above background results in both 14 C and 3 H (site A). Trias water shows non negligible 14 C and 3

  6. AMS radiocarbon dating of medieval textile relics: The frocks and the pillow of St. Francis of Assisi

    Energy Technology Data Exchange (ETDEWEB)

    Fedi, M.E. [Dipartimento di Fisica dell' Universita di Firenze and INFN Sezione di Firenze, via Sansone 1, 50019 Sesto Fiorentino (Italy)], E-mail: fedi@fi.infn.it; Cartocci, A.; Taccetti, F.; Mando, P.A. [Dipartimento di Fisica dell' Universita di Firenze and INFN Sezione di Firenze, via Sansone 1, 50019 Sesto Fiorentino (Italy)

    2008-05-15

    Since natural textiles usually originate from short-lived organisms, they can represent a useful material to date samples from historical periods with a good accuracy. In this work, we present a set of radiocarbon measurements on medieval textile relics: two woollen habits and a pillow traditionally associated with St. Francis of Assisi, the saint patron of Italy. The strategy in choosing samples for radiocarbon dating is first discussed and the procedures for measurements - performed at the 3 MV Tandetron accelerator of Laboratorio di Tecniche Nucleari per i Beni Culturali (LABEC), Florence - are described; AMS results for the two frocks showed that only one of them, presently kept in the church of St. Francis in Cortona, is compatible with the Saint's period of life, as is the pillow also kept in Cortona. Another frock attributed to St. Francis appears to date from at least 80 years after his death. However, the goal of these measurements was not a bare authentication/disconfirmation of the relics; they just represent an example of how scientific analysis can integrate with humanistic studies. Indeed, AMS results, combined with a thorough analysis of the textiles typologies, confirmed the historical hypotheses based on documentary studies and on tradition. The overall conclusions contributed to the decisions taken for conservation, and have as a whole enhanced the religious importance of the relics.

  7. AMS radiocarbon dating of medieval textile relics: The frocks and the pillow of St. Francis of Assisi

    International Nuclear Information System (INIS)

    Fedi, M.E.; Cartocci, A.; Taccetti, F.; Mando, P.A.

    2008-01-01

    Since natural textiles usually originate from short-lived organisms, they can represent a useful material to date samples from historical periods with a good accuracy. In this work, we present a set of radiocarbon measurements on medieval textile relics: two woollen habits and a pillow traditionally associated with St. Francis of Assisi, the saint patron of Italy. The strategy in choosing samples for radiocarbon dating is first discussed and the procedures for measurements - performed at the 3 MV Tandetron accelerator of Laboratorio di Tecniche Nucleari per i Beni Culturali (LABEC), Florence - are described; AMS results for the two frocks showed that only one of them, presently kept in the church of St. Francis in Cortona, is compatible with the Saint's period of life, as is the pillow also kept in Cortona. Another frock attributed to St. Francis appears to date from at least 80 years after his death. However, the goal of these measurements was not a bare authentication/disconfirmation of the relics; they just represent an example of how scientific analysis can integrate with humanistic studies. Indeed, AMS results, combined with a thorough analysis of the textiles typologies, confirmed the historical hypotheses based on documentary studies and on tradition. The overall conclusions contributed to the decisions taken for conservation, and have as a whole enhanced the religious importance of the relics

  8. AMS radiocarbon dating of medieval textile relics: The frocks and the pillow of St. Francis of Assisi

    Science.gov (United States)

    Fedi, M. E.; Cartocci, A.; Taccetti, F.; Mandò, P. A.

    2008-05-01

    Since natural textiles usually originate from short-lived organisms, they can represent a useful material to date samples from historical periods with a good accuracy. In this work, we present a set of radiocarbon measurements on medieval textile relics: two woollen habits and a pillow traditionally associated with St. Francis of Assisi, the saint patron of Italy. The strategy in choosing samples for radiocarbon dating is first discussed and the procedures for measurements - performed at the 3 MV Tandetron accelerator of Laboratorio di Tecniche Nucleari per i Beni Culturali (LABEC), Florence - are described; AMS results for the two frocks showed that only one of them, presently kept in the church of St. Francis in Cortona, is compatible with the Saint's period of life, as is the pillow also kept in Cortona. Another frock attributed to St. Francis appears to date from at least 80 years after his death. However, the goal of these measurements was not a bare authentication/disconfirmation of the relics; they just represent an example of how scientific analysis can integrate with humanistic studies. Indeed, AMS results, combined with a thorough analysis of the textiles typologies, confirmed the historical hypotheses based on documentary studies and on tradition. The overall conclusions contributed to the decisions taken for conservation, and have as a whole enhanced the religious importance of the relics.

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

    International Nuclear Information System (INIS)

    Lappin, Graham; Garner, R.Colin

    2004-01-01

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

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

    Science.gov (United States)

    Lappin, Graham; Garner, R Colin

    2004-01-01

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

  11. Accelerator mass spectrometry analysis of 14C-oxaliplatin concentrations in biological samples and 14C contents in biological samples and antineoplastic agents

    Science.gov (United States)

    Toyoguchi, Teiko; Kobayashi, Takeshi; Konno, Noboru; Shiraishi, Tadashi; Kato, Kazuhiro; Tokanai, Fuyuki

    2015-10-01

    Accelerator mass spectrometry (AMS) is expected to play an important role in microdose trials. In this study, we measured the 14C concentration in 14C-oxaliplatin-spiked serum, urine and supernatant of fecal homogenate samples in our Yamagata University (YU) - AMS system. The calibration curves of 14C concentration in serum, urine and supernatant of fecal homogenate were linear (the correlation coefficients were ⩾0.9893), and the precision and accuracy was within the acceptance criteria. To examine a 14C content of water in three vacuum blood collection tubes and a syringe were measured. 14C was not detected from water in these devices. The mean 14C content in urine samples of 6 healthy Japanese volunteers was 0.144 dpm/mL, and the intra-day fluctuation of 14C content in urine from a volunteer was little. The antineoplastic agents are administered to the patients in combination. Then, 14C contents of the antineoplastic agents were quantitated. 14C contents were different among 10 antineoplastic agents; 14C contents of paclitaxel injection and docetaxel hydrate injection were higher than those of the other injections. These results indicate that our quantitation method using YU-AMS system is suited for microdosing studies and that measurement of baseline and co-administered drugs might be necessary for the studies in low concentrations.

  12. Accelerator mass spectrometry analysis of "1"4C-oxaliplatin concentrations in biological samples and "1"4C contents in biological samples and antineoplastic agents

    International Nuclear Information System (INIS)

    Toyoguchi, Teiko; Kobayashi, Takeshi; Konno, Noboru; Shiraishi, Tadashi; Kato, Kazuhiro; Tokanai, Fuyuki

    2015-01-01

    Accelerator mass spectrometry (AMS) is expected to play an important role in microdose trials. In this study, we measured the "1"4C concentration in "1"4C-oxaliplatin-spiked serum, urine and supernatant of fecal homogenate samples in our Yamagata University (YU) – AMS system. The calibration curves of "1"4C concentration in serum, urine and supernatant of fecal homogenate were linear (the correlation coefficients were ⩾0.9893), and the precision and accuracy was within the acceptance criteria. To examine a "1"4C content of water in three vacuum blood collection tubes and a syringe were measured. "1"4C was not detected from water in these devices. The mean "1"4C content in urine samples of 6 healthy Japanese volunteers was 0.144 dpm/mL, and the intra-day fluctuation of "1"4C content in urine from a volunteer was little. The antineoplastic agents are administered to the patients in combination. Then, "1"4C contents of the antineoplastic agents were quantitated. "1"4C contents were different among 10 antineoplastic agents; "1"4C contents of paclitaxel injection and docetaxel hydrate injection were higher than those of the other injections. These results indicate that our quantitation method using YU-AMS system is suited for microdosing studies and that measurement of baseline and co-administered drugs might be necessary for the studies in low concentrations.

  13. Accelerator mass spectrometry analysis of {sup 14}C-oxaliplatin concentrations in biological samples and {sup 14}C contents in biological samples and antineoplastic agents

    Energy Technology Data Exchange (ETDEWEB)

    Toyoguchi, Teiko, E-mail: tteiko@med.id.yamagata-u.ac.jp [Department of Pharmacy, Yamagata University Hospital, 2-2-2 Iida-Nishi, Yamagata-shi, Yamagata 990-9585 (Japan); Kobayashi, Takeshi; Konno, Noboru; Shiraishi, Tadashi [Department of Pharmacy, Yamagata University Hospital, 2-2-2 Iida-Nishi, Yamagata-shi, Yamagata 990-9585 (Japan); Kato, Kazuhiro; Tokanai, Fuyuki [Department of Physics, Faculty of Science, Yamagata University, 1-4-12 Kojirakawa-machi, Yamagata-shi, Yamagata 990-8560 (Japan)

    2015-10-15

    Accelerator mass spectrometry (AMS) is expected to play an important role in microdose trials. In this study, we measured the {sup 14}C concentration in {sup 14}C-oxaliplatin-spiked serum, urine and supernatant of fecal homogenate samples in our Yamagata University (YU) – AMS system. The calibration curves of {sup 14}C concentration in serum, urine and supernatant of fecal homogenate were linear (the correlation coefficients were ⩾0.9893), and the precision and accuracy was within the acceptance criteria. To examine a {sup 14}C content of water in three vacuum blood collection tubes and a syringe were measured. {sup 14}C was not detected from water in these devices. The mean {sup 14}C content in urine samples of 6 healthy Japanese volunteers was 0.144 dpm/mL, and the intra-day fluctuation of {sup 14}C content in urine from a volunteer was little. The antineoplastic agents are administered to the patients in combination. Then, {sup 14}C contents of the antineoplastic agents were quantitated. {sup 14}C contents were different among 10 antineoplastic agents; {sup 14}C contents of paclitaxel injection and docetaxel hydrate injection were higher than those of the other injections. These results indicate that our quantitation method using YU-AMS system is suited for microdosing studies and that measurement of baseline and co-administered drugs might be necessary for the studies in low concentrations.

  14. RICH – A new AMS facility at the Royal Institute for Cultural Heritage, Brussels, Belgium

    Energy Technology Data Exchange (ETDEWEB)

    Boudin, Mathieu; Van Strydonck, Mark; Brande, Tess van den [Royal Institute for Cultural Heritage, Jubelpark 1, 1000 Brussels (Belgium); Synal, Hans-Arno; Wacker, Luckas [Laboratory of Ion Beam Physics, ETH Zurich, 8093 Zurich (Switzerland)

    2015-10-15

    Since 1989 the radiocarbon dating lab has their own graphitization system for {sup 14}C AMS dating but RICH (Royal Institute for Cultural Heritage) did not possess their own AMS and measurements were carried out in collaboration with other AMS facilities. In April 2013 the Micadas (Mini Carbon Dating System) AMS was installed at RICH in Brussels and after 1.5 year operation the high stability and performance of the Micadas can be demonstrated by repeated analyses of primary standard OXA II and secondary standards. Results of unknown samples measured on the RICH–Micadas and on other AMS systems are in good agreement.

  15. Synthesis of 14C-dehydrocorydaline chloride

    International Nuclear Information System (INIS)

    Zhang Rui; Wang Ding

    1988-01-01

    A method for synthesis of 14 C-dehydrocorydaline chloride is described. In the presence of sodium hydroxide, acetonylpalmatine is reacted with 14 C-methyl iodide in sealed glass ampoule to give 14 C-13-methylpalmatine iodide which is then converted to chloride. The radiochemical purity of 14 C-dehydrocorydaline determined by TLC is over 98% and the labelling efficiency is 54%

  16. In situ determination of 241Am on Enewetak Atoll. Date of survey: July 1977-December 1979

    International Nuclear Information System (INIS)

    Tipton, W.J.; Fritzsche, A.E.; Jaffe, R.J.; Villaire, A.E.

    1981-11-01

    An in situ gamma ray spectrometer system was operated at Enewetak Atoll from July 1977 to December 1979 in support of the Enewetak Cleanup Project. The system employed a high purity germanium planar detector suspended at a height of 7.4 m above ground. Conversion factors were established to relate measured photopeak count rate data to source concentration in the soil. Data obtained for 241 Am, together with plutonium-to-americium ratios obtained from soil sample analyses, were used to establish area-averaged surface (0 to 3 cm) transuranic concentration values. In areas which exceeded cleanup criteria, measurements were made in an iterative fashion to guide soil removal until levels were reduced below the cleanup criteria. Final measurements made after soil removal had been completed were used to document remaining surface transuranic concentration values and to establish external exposure rate levels due to 137 Cs and 60 Co

  17. Comparison of manual and automated pretreatment methods for AMS radiocarbon dating of plant fossils

    Science.gov (United States)

    Bradley, L.A.; Stafford, Thomas W.

    1994-01-01

    A new automated pretreatment system for the preparation of materials submitted for accelerator mass spectrometry (AMS) analysis is less time-consuming and results in a higher sample yield. The new procedure was tested using two groups of plant fossils: one group was pretreated using the traditional method, and the second, using the automated pretreatment apparatus. The time it took to complete the procedure and the amount of sample material remaining were compared. The automated pretreatment apparatus proved to be more than three times faster and, in most cases, produced a higher yield. A darker discoloration of the KOH solutions was observed indicating that the automated system is more thorough in removing humates from the specimen compared to the manual method. -Authors

  18. Behaviors of 14C-butachlor, 14C-chlorpyrifos and 14C-DDT in Rana japonica japonica Guenther

    International Nuclear Information System (INIS)

    Zhang Yiqiang; Zhong Chuangguang; Zhao Xiaokui; Chen Shunhua

    2002-01-01

    The research on the behaviors of 14 C-butachlor, 14 C-chlorpyrifos and 14 C-DDT in the frog Rana japonica japonica Guenther was carried out. After administrated per os to the frogs in doses of 380, 347, 363 Bq/g, 14 C-butachlor, 14 C-chlorpyrifos and 14 C-DDT, were distributed respectively to various organs within 24 h with specific accumulating organs as gallbladder, intestine and intestine, relevantly to the pesticides described. Compared to that in gallbladder and intestine, the radioactivity of many organs was extremely low, and this might due to the characters of the pesticides. Analysis of the metabolites of 14 C-DDT in frog at 24 th hr demonstrated that DDT was difficult to be degraded. Most 14 C-butachlor, 14 C-chlorpyrifos 14 C-DDT in liver and fat or ovary of frog was extractable with acetone. However, there were some differences between the pesticides, and the organs as well. And 14 C-butachlor, 14 C-chlorpyrifos or 14 C-DDT were better bound in liver than in fat

  19. Application of Alkenone 14C-Based chronostratigraphy in carbonate barren sediments on the Peru Margin.

    Science.gov (United States)

    Higginson, M. J.; Altabet, M. A.; Herbert, T. D.

    2003-04-01

    Despite the availability of high-quality sediment cores in key locations, little paleoclimatic information exists for the Peru margin largely because poor carbonate preservation severely restricts the use of traditional carbonate-based proxies for stratigraphy, dating, and paleo-environmental reconstruction. Many sites also include hiatuses produced by the variable influence of undercurrents on sediment accumulation. To overcome these difficulties, we have developed (in collaboration with T. Eglinton, WHOI) a laboratory facility to successfully extract and purify haptophyte-derived alkenones for compound specific 14C AMS dating (modified from OHKOUCHI et al., 2002). This avoids potential problems with dating bulk organic carbon which we assume, even in an upwelling environment as highly productive as the Peru margin, is not a priori solely of marine origin. In a recently collected, mid-Peru Margin core (ODP Leg 201 Site 1228D), comparison of our alkenone 14C dates with bulk sediment organic carbon dates and known stratigraphic markers produces a very well constrained, curvilinear age-depth relationship for at least the last 14 Kyr. A discrete ash layer at Site 1228D with an adjacent alkenone 14C age of 3890 ± 350 yr, is within error identical to the 14C age of a prominent ash layer (3800 ± 50 yr) found west of the large Peruvian El Misti volcano (16^o18'S, 71^o24'W). In summary, these results show that the Peru margin alkenones are autochthonous (i.e. not from an older, distant source) and provide sufficient dating precision to permit, for the first time, high-resolution paleoceanographic studies in this highly important marine province. Based upon this new chronology, synchronous changes in alkenone-derived SST estimates in two of our independently-dated records are the first to record at high-resolution (a) a large LGM-Holocene SST range in the Tropics (up to 7.8 ^oC during brief events in this upwelling location); and (b) sharp coolings (4 ^oC) consistent with

  20. /sup 14/C uncovers the past

    Energy Technology Data Exchange (ETDEWEB)

    1977-01-01

    Radiocarbon dating, a method of dating prehistoric remains that has been developed since the Second World War, is based on the fact that all organic matter contains a radioactive isotope of carbon -/sup 14/C- which, because it decays at a fixed rate, gives a good indication of the age of the substance. The CSIR's National Physical Research Laboratory entered the field of radio-carbon dating in 1967, when the Nature Isotopes Division was established. The division has become a world center of excellence and much has been done to clear up the chronology of southern African prehistory. It has been found, for instance, that anatomically modern man appeared in southern Africa some 40000 years earlier than in Europe, and that the Zimbabwe ruins were built mainly around the year 1350 AD. The radio-carbon method can also be used to determine the age and flow rate of underground water and the rate at which tracer gases dissolve in the oceans, i.e. the efficiency with which the oceans cleanse the atmosphere from pollutants.

  1. Bepaling van 14C in afvalwater

    NARCIS (Netherlands)

    Hiemstra YS; Kwakman PJM; Nissan LN; Aldenkamp FJ; LSO

    1998-01-01

    In opdracht van de Hoofdinspectie Milieuhygiene van het ministerie van VROM heeft LSO een methode ontwikkeld om 14C in afvalwater van nucleaire installaties te bepalen. De methode meet organisch gebonden-14C en anorganisch-14C in de vorm van carbonaat (14CO32-) in afvalwater. Het rapport

  2. 14C ages for the ejecta from Kutcharo and Mashu calderas, eastern Hokkaido, Japan

    International Nuclear Information System (INIS)

    Yamamoto, Takahiro; Ito, Jun-ichi; Nakagawa, Mitsuhiro; Hasegawa, Takeshi; Kishimoto, Hiroshi

    2010-01-01

    Eruption ages of the ejecta from Kutcharo and Mashu calderas were systematically determined by 14 C dating. 16 charred samples were newly obtained from the Mashu and Nakashumbetsu Tephra Formations around the calderas and dated by AMS and β-counting methods. Examined units are Ma-d, Ma-e, Ma-f, Ma-j, Ma-k, Ma-l and Ml-a in the Mashu ejecta and 6 Nakashumbetsu tephra layers including Kutcharo Pumice Flow Deposit I (KpI), which is the youngest caldera-forming product from Kutcharo caldera. Results of the 14 C dating range from 3,660 ±40 yBP to 36,080±1,300 yBP, and are consistent with the tephrostratigraphy. Calendar age for KpI was newly calculated at almost 40 ka and this age shows there was about 70,000 years recurrence interval between KpI and KpIV caldera-forming eruptions. Mashu caldera has appeared on the eastern part of Kutcharo caldera immediately after the KpI eruption, and calendar age for its main caldera-forming eruption were determined at ca. BC 5,600. (author)

  3. Convenient synthesis of [2-14C]-methylglyoxal bis(guanylhydrazone), [14C]-mitoguazone

    International Nuclear Information System (INIS)

    Burgos, A.; Ellames, G.J.

    1995-01-01

    [2- 14 C]-Methylglyoxal bis(guanylhydrazone) dihydrochloride, [ 14 C]-mitoguazone has been prepared in three steps from potassium[1- 14 C]-acetate in an overall radiochemical yield of 16%. The key steps in this procedure are the formation of the sodium salt of[acetone-2- 14 C]-methylsulfinylacetone, and Pummerer rearrangement to the [ 14 C] labelled hermithioacetal, which is trapped with two equivalents of aminoguanidine to afford the desired [ 14 C]-mitoguazone. (Author)

  4. Feasibility studies of RFQ based 14C accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Guo Zhiyu; Liu Kexin; Yan Xueqing; Xie Yi; Fang Jiaxun; Chen Jiaer

    2007-01-01

    Electrostatic accelerators with terminal voltage less than 1 MeV have been successfully used for 14 C AMS. This contribution shows that a small RFQ accelerator may also be suitable for AMS 14 C measurements. A well-designed RFQ accelerator can realize a low energy spread and high isotopic selection with a length of less than 1 m and reasonable power consumption. Compared with small tandem accelerators, a RFQ does not need isolation gas and can accept much higher beam currents. Its stripper would be at ground potential and there would be no further acceleration after stripping, so the background from charge exchange processes should be lower. The RFQ design and system are described

  5. Synthesis of [3-14C]- and [phenyl-U-14C] olaquindox

    International Nuclear Information System (INIS)

    Maul, W.; Scherling, D.; Seng, F.

    1981-01-01

    Olaquindox is a new feed additive. [ 14 C]Olaquindox, labelled in different positions, was needed for tracer-studies of pharmacokinetics, biotransformation and residues in several species of animals. 2-[N-(2-hydroxethyl)-carbamoyl]-3-methyl-[3- 14 C]quinoxaline-1,4-dioxide([3- 14 C]Olaquindox) was synthesized from barium[ 14 C]carbonate (22 mmoles; 1.15 Ci) via [1- 14 C]acetic acid, sodium[1- 14 C]acetate, [1- 14 C]acetylchloride, ethyl[3- 14 C]acetoacetate and 2-carbethoxy-3-methyl-[3- 14 C]quinoxaline-1,4-dioxide with an overall yield of 10%, based on barium[ 14 C]carbonate. The radiochemical purity was better than 98% (tlc). The specific activities of three preparations were 10.5, 8.4 and 5.45 μCi/mg respectively. [phenyl-U- 14 C]Olaquindox was synthesized starting from [U- 14 C]aniline (19.8 mmoles; 284.4 mCi). Intermediate products were N-acetyl[U- 14 C]aniline, 2-nitro-N-acetyl[U- 14 C]aniline, 2-nitro[U- 14 C]aniline and [U- 14 C]benzofurazanoxide. The total yield was 50% as calculated for [U- 14 C]aniline. At calibration samples of two preparations showed specific activities of 49.5 and 11.1 μCi/mg respectively. The radiochemical purity was checked by tlc and exceeded 98%. (author)

  6. AMS measurements

    International Nuclear Information System (INIS)

    Lawson, E.M.

    1999-01-01

    Accelerator mass spectrometry (AMS) ia an ultrasensitive analysis technique using a system based on a nuclear particle accelerator and its beam transport system to detect and measure individual 14 C ions.. In AMS a 14 C abundance is obtained by comparing the measurement rates of 14 C and 13 C ions. This is not as simple as it sounds. The enormous difference in the numbers of the two isotopes makes it very hard to uniquely detect 14 C ions. For modern samples, those with the most 14 C, some 10 10 13 C ions leave the source for every 14 C ion. However, the use of an accelerator and various high energy techniques makes it possible to the detect the 14 C and to reject the 13 C. in order to achieve this high rejection efficiency the injection magnet is set to transmit only one isotope, namely 14 C. However, a subsequent measurement of 13 C must be made. The number and the rate of arrival of 13 C ions is such that individual ions cannot be measured, instead a 13 C current is measured in a Faraday cup. It is possible to alternate the injection magnet field between that to transmit 14 C and that to transmit 13 C. This method is known as slow cycling but suffers from significant dead (not useful) periods while the magnet field is changed and stabilises. Furthermore and more significantly, during this dead time changes in ion source output may occur distorting the 14 C/ 13 C ratio. We instead employ a method known as fast cycling which involves rapidly increasing the energy of the 13 C ions as they enter the injection magnet. This is achieved by the use of a high voltage (6.7 kV) pulser. We can also inject 12 C by this method although a 14.7 kV pulse is required. The switching time from one carbon isotope to another is only a fraction of a millisecond in this fast cycling method. Hence one has quasi-simultaneous measurement of 14 C and 13 C. Measurements of the 14 C/ 13 C ratio from a sample are always compared to the same ratio from an internationally accepted standard

  7. A convenient synthesis of sup 14 C-cotinine from sup 14 C-nicotine

    Energy Technology Data Exchange (ETDEWEB)

    Desai, D.H.; Djordjevic, M.V.; Amin, S. (American Health Foundation, Valhalla, NY (USA). Naylor Dana Inst. for Disease Prevention)

    1991-03-01

    A convenient synthesis with analytical monitoring of {sup 14}C-cotinine is reported. {sup 14}C-Nicotine was converted into {sup 14}C-dibromocotinine hydrobromide perbromide. Debromination, achieved by using Zn dust/acetic acid, resulted in high yields (71%) of {sup 14}C-cotinine. (author).

  8. Synthesis of pinacolyl [14C]methylphosphonochloridate

    International Nuclear Information System (INIS)

    Horvat, J.; Keglevic, D.; Klaic, B.; Kveder, S.; Ladesic, B.; Cosic, M.; Zupanc, S.

    1982-01-01

    A three-step synthetic route to pinacolyl [ 14 C]methylphosphonochloridate (3) from [ 14 C]methyl iodide is described. Condensation of sodium di-n-butyl phosphite with [ 14 C]methyl iodide gave di-n-butyl [ 14 C]methylphosphonate (1) which was converted into [ 14 C]methylphosphonic dichloride (2) by prolonged refluxing with thionyl chloride. Reaction of 2 with pinacolyl alcohol in the presence of N,N-di-n--propylaniline as the base afforded the title compound 3. The radiochemical yield of redistilled 3 was 34,2% based on 1, and the overall radiochemical yield was 20,0% from [ 14 C]methyl iodide. (author)

  9. Benzene Synthesis for 14C Measurements and Evaluation of Uncertainty in Mollusk Shells

    International Nuclear Information System (INIS)

    Romero del Hombrebueno, B.; Simon, M. A.; Larena, P.

    2002-01-01

    This work describes the method and Instrumentation used by Environmental Isotopes laboratory of the CIEMAT Analytical Chemistry Laboratory (DIAE) for the synthesis of benzene from carbonates of mollusk shells and the liquid scintillation counting of 14 C for radiocarbon dating in these samples. The usefulness of mollusk shells for 14 C dating are considered. (Author) 15 refs

  10. Stratigraphy and AMS radiocarbon dates of cored sediments (IrBH-2) from the Irosin caldera, the Philippines

    International Nuclear Information System (INIS)

    Mirabueno, Ma. Hannah T.; Laguerta, Eduardo P.; Delos Reyes, Perla J.; Bariso, Ericson B.; Torii, Masayuki; Fujiki, Toshiyuki; Okuno, Mitsuru; Nakamura, Toshio; Danhara, Tohru; Saito-Kokubu, Yoko; Kobayashi, Tetsuo

    2014-01-01

    Core drilling at Site IrBH-2 within the Irosin caldera in Sorsogon Province, southern Luzon reached a depth of 50 m. Systematic logging and documentation were carried out to describe and interpret the sediments. The accelerator mass spectrometer (AMS) radiocarbon dates obtained from plant fragments at 7.02-10.40-m depth were 1000 to 1800 BP. Lahars and fluvial deposits were the predominant deposits in the core sequence. The upper 12 m consisted mostly of andesitic fluvial and minor lahar deposits. These deposits may be correlated with the reworking of eruptive products from resurgent andesitic volcanism. One pyroclastic flow and 12 fallout deposits, including five possible fallout deposits, were intercalated with reworked sediments at depths of 12-50 m. The refractive index of representative samples indicated that post-caldera eruptions involved mainly andesite to dacite, with minor rhyolite magmas. The rhyolite fallout in the core had similar petrographic characteristics to the 41 cal kBP Irosin ignimbrite, suggesting that the fallout and the ignimbrite were sourced from the same magma. (author)

  11. Can we constrain postglacial sedimentation in the western Arctic Ocean by ramped pyrolysis 14C? A case study from the Chukchi-Alaskan margin.

    Science.gov (United States)

    Suzuki, K.; Yamamoto, M.; Rosenheim, B. E.; Omori, T.; Polyak, L.; Nam, S. I.

    2017-12-01

    The Arctic Ocean underwent dramatic climate changes in the past. Variations in sea-ice extent and ocean current system in the Arctic cause changes in surface albedo and deep water formation, which have global climatic implications. However, Arctic paleoceanographic studies are lagging behind the other oceans due largely to chronostratigraphic difficulties. One of the reasons for this is a scant presence of material suitable for 14C dating in large areas of the Arctic seafloor. To enable improved age constraints for sediments impoverished in datable material, we apply ramped pyrolysis 14C method (Ramped PyrOx 14C, Rosenheim et al., 2008) to sedimentary records from the Chukchi-Alaska margin recovering Holocene to late-glacial deposits. Samples were divided into five fraction products by gradual heating sedimentary organic carbon from ambient laboratory temperature to 1000°C. The thermographs show a trimodal pattern of organic matter decomposition over temperature, and we consider that CO2 generated at the lowest temperature range was derived from autochthonous organic carbon contemporaneous with sediment deposition, similar to studies in the Antarctic margin and elsewhere. For verification of results, some of the samples treated for ramped pyrolysis 14C were taken from intervals dated earlier by AMS 14C using bivalve mollusks. Ultimately, our results allow a new appraisal of deglacial to Holocene deposition at the Chukchi-Alaska margin with potential to be applied to other regions of the Arctic Ocean.

  12. Synthesis of (/sup 14/C)Zolpidem

    Energy Technology Data Exchange (ETDEWEB)

    Allen, J.; Tizot, A.

    1986-04-01

    The synthesis of (/sup 14/C)Zolpidem, a new hypnotic agent having a non-benzodiazepine structure, is described. This compound was synthesised in a 64% overall radiochemical yield from potassium (/sup 14/C)cyanide and with a specific radioactivity of 56 mCi/mmol. It was used for pharmacokinetic and drug metabolism studies.

  13. Synthesis of [14C]Zolpidem

    International Nuclear Information System (INIS)

    Allen, J.; Tizot, A.

    1986-01-01

    The synthesis of [ 14 C]Zolpidem, a new hypnotic agent having a non-benzodiazepine structure, is described. This compound was synthesised in a 64% overall radiochemical yield from potassium [ 14 C]cyanide and with a specific radioactivity of 56 mCi/mmol. It was used for pharmacokinetic and drug metabolism studies. (author)

  14. Synthesis of 14C-labelled milrinone

    International Nuclear Information System (INIS)

    Duncan, D.R.; Johnston, D.; Andrews, R.S.

    1985-01-01

    A synthetic procedure for producing 14 C-labelled milrinone, a potent new cardiotonic agent, is described. The synthesis was achieved in two steps from 1-(4-pyridyl)propan-2-one utilising [2- 14 C]cyanoacetamide as the source of the radiolabel. The overall chemical yield was 46% and the radiochemical yield 35%. (author)

  15. Formation of 14C-asparagine from 14C-precursor in mulberry leaves

    International Nuclear Information System (INIS)

    Yamashita, Tadaaki

    1981-01-01

    Since a remarkable accumulation of asparagine in the young leaves of mulberry has been observed, the formation of 14 C-asparagine from 14 C-labeled substrates in young leaves was examined in comparison with that in the mature leaves. 14 C-aspartic acid and 14 C-succinic acid expected as active precursors for asparagine biosynthesis, and 14 C-sucrose as respiratory substrates were fed respectively to the disks of young or mature leaves of mulberry. Although 14 C-succinic acid was actively converted to 14 C-asparagine, no significant amount of 14 C-asparagine was formed from 14 C-aspartic acid in two hours of feeding period. The rate of formation of 14 C-asparagine from 14 C-succinic acid in the mature leaves was slightly higher than that in the young leaves. Amino acids other than asparagine acquired 14 C from 14 C-labeled substrates were mainly aspartic acid, glutamic acid, alanine and ν-amino butyric acid in both of the leaves. Intending to accelerate the formation of asparagine in the leaves, ammonium ion was supplied to culturing solution as only source of nitrogen and plants were grown for two weeks in that solution before 14 C-labeled substrates feeding experiments. Supplying of ammonium ion brought about enhanced accumulation of asparagine in the young leaves, and caused remarkable formation of 14 C-asparagine from 14 C-aspartic acid in both of the leaves. However, the rate of 14 C-asparagine formation from 14 C-aspartic acid in the young leaves did not exceed that in the mature leaves. (author)

  16. A high resolution method for {sup 14}C analysis of a coral from South China Sea: Implication for “AD 775” {sup 14}C event

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Ping [State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 510640 Guangzhou (China); Shen, Chengde, E-mail: cdshen@gig.ac.cn [State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 510640 Guangzhou (China); State Key Laboratory of Nuclear Physics and Technology, Peking University, 100871 Beijing (China); Yi, Weixi; Wang, Ning [State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 510640 Guangzhou (China); Ding, Xingfang; Liu, Kexin; Fu, Dongpo [State Key Laboratory of Nuclear Physics and Technology, Peking University, 100871 Beijing (China); Liu, Weiguo [State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, The Chinese Academy of Sciences, 710075 Xi’an (China); Liu, Yi [CAS Key Laboratory of Crust-Mantle Materials and Environments, School of Earth and Space Sciences, University of Science and Technology of China, 230026 Hefei (China)

    2015-10-15

    A pre-heating method that improves the background and precision of {sup 14}C dating significantly was applied for fossil coral dating with high resolution in our lab in Guangzhou Institute of Geochemistry, Chinese Academy of Sciences (GIGCAS). The reaction tube is heated under 300 °C in a vacuum line before it is used for graphitization. The method can reduce the contamination absorbed in TiH{sub 2}, Zn and Fe power placed in the graphitization tube. With the pre-heating and average drilling method, bi-weekly resolution {sup 14}C dating in a fossil coral is carried out to investigate the “AD 775 {sup 14}C spike event”. Different from the tree ring {sup 14}C archives with the {sup 14}C spike of ∼15‰ (Δ{sup 14}C), the {sup 14}C spike in the coral shows an abrupt peak of 45‰ and two smaller spikes of Δ{sup 14}C > 20‰ in half a year in AD 776. And then, the {sup 14}C content in coral decreases gradually in AD 777. The peak time of the {sup 14}C spike event likely occurs in the summer of AD 776 according to the δ{sup 18}O variation in coral. High-resolution dating of {sup 14}C in coral provides not only a more detail process of the event than that from tree rings, but also the first report of the event from sea ecosystem. Both of them suggest an extraterrestrial origin of the event cause.

  17. Preparation of arginine (guanide 14C)

    International Nuclear Information System (INIS)

    Pichat, L.; Baret, C.

    1960-01-01

    Reaction of anhydrous ammoniac at 800 deg. C on 14 CO 3 Ba gives rise to barium cyanamide 14 C with a yield of about 98 per cent. Addition on H 2 S on cyanamide 14 C leads to thiourea 14 C with a 85 per cent yield, which is quantitatively transformed into S-ethyl-isothiouronium iodide by treatment with methyl iodide. This 14 C-isothiouronium salt is used to introduce 14 C guanide group in α-N-tosyl-ornithine; tosyl group in α-N-tosyl-arginine thus obtained is then removed by hydrolysis with hydrochloric acid. Arginine is separated as flavianic acid salt and is purified on exchange resin Dowex-50. The overall yield based on 14 CO 3 Ba is 25 per cent. (author) [fr

  18. 14C concentrations in tree stems, 1

    International Nuclear Information System (INIS)

    Kikata, Yoji; Yonenobu, Hitoshi; Morishita, Fumio; Hattori, Yoshiaki; Marsoen, S.N.

    1993-01-01

    The 14 C concentrations in trees sampled at various latitudes were measured with a Tandetron Accelerator Mass Spectrometer at Nagoya University. The growing periods of the parts for 14 C measurements were estimated by the relationship between meteorological conditions and the appearance of anatomical features of annual rings such as false rings, latewood formation, and so on. The following results were obtained: 1. The latitude dependence of the 14 C variation is found in tree stems as well as in the atmosphere. 2. The 14 C concentrations in tree stems are almost equal to those in the atmosphere at the latitude where the tree had grown and at the time when the sampled section is formed. Therefore the 14 C concentrations in the atmosphere are estimated by those of the tree stems. 3. The time when the 14 C concentration in the tree showed its maximum value has difference of 1 - 2 years with that of the latitude where the tree had grown. 4. This phenomena seemed to be related closely with the mechanism of global mixing of 14 CO 2 produced by atmospheric nuclear weapon tests. This mechanism causes a time lag of 14 C variation between northern and southern hemisphere. (author)

  19. 10Be and 14C in the Earth system

    International Nuclear Information System (INIS)

    Oeschger, H.; Beer, J.; Andree, M.

    1987-01-01

    In a very short period of time, 10 Be data have significantly improved our knowledge in various fields of Earth and planetary sciences. Examples are solar modulation of isotope production, revealed in 10 Be ice-core profiles; geomagnetic modulation of isotope production, revealed in 10 Be ice-core (from the past 10 ka) and ocean-sediment profiles (geomagnetic reversals); climatic effects reflected in 10 Be profiles in loess and polar ice cores ( 10 Be behaviour in atmosphere); comparison of 10 Be and 14 C variations (tree rings) from carbon-cycle models and information on ocean circulation history from 14 C measurements on benthic and planktonic Foraminifera in ocean sediments. An overview on work in collaboration with the Zurich AMS (accelerator mass spectroscopy) facility is given. (author)

  20. 14C Records from Indonesian Sea

    International Nuclear Information System (INIS)

    Baresic, J.; Fallon, S.; Mazerat, J.

    2013-01-01

    To investigate ocean currents and past climate events affecting the Indonesian throughflow (ITF), a radiocarbon record from a Porites coral collected from Alor Island, Indonesia, was constructed. Porites corals are often used in paleoclimate research and water mass circulation studies in the Tropics because of their abundance in the region and growth rate of 8 - 20 mm/y. These characteristics allow reconstructions of past environmental changes on weekly to annual time scales. At this point radiocarbon coral results from Alor cover approximately 30 years. An age model was constructed using the sea surface temperature proxy δ18O. Alor radiocarbon results were compared with previous measurements obtained from Padang and Langkai corals. a14C values obtained from the Alor coral display a strong seasonal cycle, high values during Australian summer and low values during Australian winter. Higher a 14C summer values indicate inflow of waters enriched by 14C through Makassar Strait from the North Pacific Ocean and Java Sea surface water. Summer a14C values are also enhanced by summer stratification. Winter values indicate upwelling of deep Ocean waters within the research area and transport of 14C-depleted waters from the Banda Sea, which has input from the South Pacific Ocean (lower a14C than North Pacific). Therefore, the a14C coral record reflects the movement of enriched water from North Pacific to Indian Ocean through Makassar Strait during summer and upwelling of depleted surface waters from the Banda Sea during the winter. Lower a14C dips could be attributed to strong El Nino events, which would enhance surface water mixing and upwelling of low radiocarbon deep waters. Water transport from North Pacific Ocean decreases during El Nino events also contributing to lowering of a14C signal.(author)

  1. 14C levels in Trombay environment

    International Nuclear Information System (INIS)

    Doshi, G.R.; Sadarangani, S.H.; Krishnamoorthy, T.M.

    1994-01-01

    The passive air sampling method has been used to measure the spatial distribution of the specific activity of 14 C in air samples collected within the Trombay complex. The samples collected within radial distance of about 0.5 km from Cirus showed 3 to 5 times higher specific activity of 14 C over the natural background level of 6.2 pCi/g C. The same decreased with the distance and approached the value of natural level at the site boundary (1.6 km). The specific activity of 14 C in leaf samples collected within the complex showed the similar pattern. (author). 6 refs., 2 tabs

  2. Biodegradation mechanism of linear alkylbenzenesulfonate-14C

    International Nuclear Information System (INIS)

    Kubodera, Tadayoshi; Muto, Toshio; Yamamoto, Tatsuo

    1978-01-01

    The biodegradation of linear alkylbenzenesulfonate- 14 C (LAS- 14 C) tagged with 14 C at the linear side chain was studied on activated sludge by tracer method in addition to the methylene blue method which is widely employed in the biodegradation of LAS. It was found that there were three periods of rapid adsorption period, acclimation period, and degradation process. The radiolysis of dodecylbenzenesulfonate was studied on irradiating by 5000 Ci 60 Co source. The decomposition products were identified by GLC and GC-MS spectrometry after desulfonation. 1-Tetralone, 1-indanone, 4-methyl-1-tetralone, naphthalene et al. were found in them. (author)

  3. [14C]Virginiamycin residues in eggs

    International Nuclear Information System (INIS)

    Corpet, D.E.; Baradat, M.; Bories, G.F.

    1988-01-01

    Laying hens were fed ab libitum a diet supplemented at 40, 10, and 0 mg/kg with [ 14 C]virginiamycin, to determine whether or not virginamycin or its metabolites were transferred to the eggs. About 0.05% of the ingested 14 C dose was recovered in the eggs. Radiolabeled residues expressed in terms of virginiamycin equivalents were found to be 5.1 ng/g in the albumen and 31.8 ng/g in the yolk from hens fed a 10 mg/kg diet. No antibiotic activity could be detected in the eggs. Tentative identifications showed that in the albumen about 17% of the 14 C behaved chromatographically like virginiamycin and 18% was associated to the ovalbumin. In the yolk 31% of the 14 C was associated to proteins, 58% to fatty acids, and 4% to unsaponifiable matter

  4. Evaluation of 14C abundance in soil respiration using accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Koarashi, Jun; Iida, Takao; Moriizumi, Jun; Asano, Tomohiro

    2004-01-01

    To clarify the behavior of 14 C in terrestrial ecosystems, 14 C abundance in soil respiration was evaluated in an urban forest with a new method involving a closed chamber technique and 14 C measurement by accelerator mass spectrometry (AMS). Soil respiration had a higher Δ 14 C than the contemporary atmosphere. This indicates that a significant portion of soil respiration is derived from the decomposition of soil organic matter enriched in 14 C by atmospheric nuclear weapons tests, with a notable time lag between atmospheric 14 C addition and re-emission from soil. On the other hand, δ 14 C in soil respiration demonstrated that 14 C abundance ratio itself in soil-respired CO 2 is not always high compared with that in atmospheric CO 2 because of the isotope fractionation during plant photosynthesis and microbial decomposition of soil organic matter. The Δ 14 C in soil respiration was slightly lower in August than in March, suggesting a relatively high contribution of plant root respiration and decomposition of newly accumulated and/or 14 C-depleted soil organic matter to the total soil respiration in August

  5. Human folate metabolism using 14C-accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Arjomand, A; Bucholz, B A; Clifford, A J; Duecker, S R; Johnson, H; Schneider, P D; Zulim, R A.

    1999-01-01

    Folate is a water soluble vitamin required for optimal health, growth and development. It occurs naturally in various states of oxidation of the pteridine ring and with varying lengths to its glutamate chain. Folates function as one-carbon donors through methyl transferase catalyzed reactions. Low-folate diets, especially by those with suboptimal methyltransferase activity, are associated with increased risk of neural tube birth defects in children, hyperhomocysteinemic heart disease, and cancer in adults. Rapidly dividing (neoplastic) cells have a high folate need for DNA synthesis. Chemical analogs of folate (antifolates) that interfere with folate metabolism are used as therapeutic agents in cancer treatment. Although much is known about folate chemistry, metabolism of this vitamin in vivo in humans is not well understood. Since folate levels in blood and tissues are very low and methods to measure them are inadequate, the few previous studies that have examined folate metabolism used large doses of radiolabeled folic acid in patients with Hodgkins disease and cancer (Butterworth et al. 1969, Krumdieck et al. 1978). A subsequent protocol using deuterated folic acid was also insufficiently sensitive to trace a physiologic folate dose (Stites et al. 1997). Accelerator mass spectrometry (AMS) is an emerging bioanalytical tool that overcomes the limitations of traditional mass spectrometry and of decay counting of long lived radioisotopes (Vogel et al. 1995). AMS can detect attomolar concentrations of 14 C in milligram-sized samples enabling in vivo radiotracer studies in healthy humans. We used AMS to study the metabolism of a physiologic 80 nmol oral dose of 14 C-folic acid (1/6 US RDA) by measuring the 14 C-folate levels in serial plasma, urine and feces samples taken over a 150-day period after dosing a healthy adult volunteer

  6. Syntheses of [6-14C] and [5-carboxy, 6-14C2]nitrendipine

    International Nuclear Information System (INIS)

    Maul, N.; Scherling, D.

    1989-01-01

    [6- 14 C]Nitrendipine synthesis started from barium[ 14 ]carbonate, which was converted to [1- 14 C]acetyl chloride. The acid chloride was condensed with Meldrum's acid (2,2-dimethyl-1,3-dioxane-4,6-dione). The resulting intermediate was treated with boiling methanol to give methyl [3- 14 C]acetoacetate. The reaction with gaseous ammonia in toluene yielded the corresponding methyl 3-amino[3- 14 C]crotonate which was condensed with ethyl 2-(3-nitro-benzylidene) acetoacetate to obtain [6- 14 C]nitrendipine. (author)

  7. Syntheses of (6- sup 14 C) and (5-carboxy, 6- sup 14 C sub 2 )nitrendipine

    Energy Technology Data Exchange (ETDEWEB)

    Maul, N.; Scherling, D. (Bayer AG, Wuppertal (Germany, F.R.). Inst. fuer Pharmakologie)

    1989-04-01

    (6-{sup 14}C)Nitrendipine synthesis started from barium({sup 14})carbonate, which was converted to (1-{sup 14}C)acetyl chloride. The acid chloride was condensed with Meldrum's acid (2,2-dimethyl-1,3-dioxane-4,6-dione). The resulting intermediate was treated with boiling methanol to give methyl (3-{sup 14}C)acetoacetate. The reaction with gaseous ammonia in toluene yielded the corresponding methyl 3-amino(3-{sup 14}C)crotonate which was condensed with ethyl 2-(3-nitro-benzylidene) acetoacetate to obtain (6-{sup 14}C)nitrendipine. (author).

  8. Low-level (submicromole) environmental 14C metrology

    International Nuclear Information System (INIS)

    Currie, L.A.; Kessler, J.D.; Marolf, J.V.; McNichol, A.P.; Stuart, D.R.; Donoghue, J.C.; Donahue, D.J.; Burr, G.S.; Biddulph, D.

    2000-01-01

    Accelerator mass spectrometry (AMS) measurements of environmental 14 C have been employed during the past decade at the several micromole level (tens of μg carbon), but advanced research in the atmospheric and marine sciences demands still higher (μg) sensitivity, an extreme example being the determination of 14 C in elemental or 'black' carbon (BC) at levels of 2-10 μg per kg of Greenland snow and ice (Currie et al., 1998). A fundamental limitation for 14 C AMS is Poisson counting statistics, which sets in at about 1 μg modern-C. Using the small sample (25 μg) AMS target preparation facility at NOSAMS (Pearson et al., 1998), and the microsample combustion-dilution facility at NIST, we have demonstrated an intrinsic modern-C quantification limit (m Q ) of ca. 0.9 μg, based on a 1-parameter fit to the empirical AMS variance function. (For environmental 14 C, the modern carbon quantification limit is defined as that mass (m Q ) corresponding to 10% relative standard deviation (rsd) for the fraction of modern carbon, σ(f M )/f M .) Stringent control, required for quantitative dilution factors (DL), is achieved with the NIST on-line manometric/mass spectrometry facility that compensates also for unsuspected trace impurities from vigorous chemical processing (e.g., acid digestion). Our current combustion blank is trivial (mean: 0.16 ± 0.02 μg C, n=13) but lognormally distributed (dispersion [σ]: 0.07 ± 0.01 μg). An iterative numerical expression is introduced to assess the quantitative impacts of fossil and modern carbon blank components on m Q ; and a new 'clean chemistry' BC processing system is described for the minimization of such blanks. For the assay of soot carbon in Greenland snow/ice, the overall processing blank has been reduced from nearly 7 μg total carbon to less than 1 μg, and is undetectable for BC

  9. Uptake and distribution of 14C during and following exposure to [14C]methyl isocyanate

    International Nuclear Information System (INIS)

    Ferguson, J.S.; Kennedy, A.L.; Stock, M.F.; Brown, W.E.; Alarie, Y.

    1988-01-01

    Guinea pigs were exposed to [ 14 C]methyl isocyanate ( 14 CH 3 -NCO, 14 C MIC) for periods of 1 to 6 hr at concentrations of 0.5 to 15 ppm. Arterial blood samples taken during exposure revealed immediate and rapid uptake of 14 C. Clearance of 14 C was then gradual over a period of 3 days. Similarly 14 C was present in urine and bile immediately following exposure, and clearance paralleled that observed in blood. Guinea pigs fitted with a tracheal cannula and exposed while under anesthesia showed a reduced 14 C uptake in blood indicating that most of the 14 C MIC uptake in normal guinea pigs occurred from retention of this agent in the upper respiratory tract passages. In exposed guinea pigs 14 C was distributed to all examined tissues. In pregnant female mice similarly exposed to 14 C MIC, 14 C was observed in all tissues examined following exposure including the uterus, placenta, and fetus. While the form of 14 C distributed in blood and tissues has not yet been identified, these findings may help to explain the toxicity of MIC or MIC reaction products on organs other than the respiratory tract, as noted by several investigators

  10. A new AMS facility based on a Cockcroft-Walton type 1 MV tandetron at IFIN-HH Magurele, Romania

    Science.gov (United States)

    Stan-Sion, C.; Enachescu, M.; Ghita, D. G.; Calinescu, C. I.; Petre, A.; Mosu, D. V.; Klein, M.

    2014-01-01

    A 1 MV AMS machine was recently installed in the National Institute for Physics and Nuclear Engineering IFIN-HH, Bucharest Romania. It is the second AMS facility at IFIN-HH having the goal not only to continue but mainly to enlarge the research area of this highly sensitive analyzing method. The multi-element AMS was developed by HVEE to measure 14C, 10Be, and 26Al, and 129I. The results of an acceptance test are presented and demonstrate that this machine is capable of routine 14C age dating and of measurements of other radioisotopes in terms of accuracy and precision as well as a low background level.

  11. Groundwater flowpaths and residence times inferred by 14C, 36Cl and 4He isotopes in the Continental Intercalaire aquifer (North-Western Africa)

    Science.gov (United States)

    Petersen, J. O.; Deschamps, P.; Hamelin, B.; Fourré, E.; Gonçalvès, J.; Zouari, K.; Guendouz, A.; Michelot, J.-L.; Massault, M.; Dapoigny, A.; ASTER Team

    2018-05-01

    In a semi-arid to arid climate context, dependency on groundwater resources may lead to overexploitation and deterioration of water quality. The Continental Intercalaire (CI) aquifer is one such continental-scale aquifer (more than a million of km2), which is mainly confined, poorly recharged but intensely abstracted. To date, the management of this resource relies on hydrogeological modelling and key parameters such as recharge/discharge rate and groundwater dynamics. We use a combination of residence time indicators (14C, 36Cl, 4He) and stable isotopes of water (2H and 18O) to give greater constraint on the groundwater residence time in the CI. In previous studies, 14C measurements and steady state modelling indicate a residence time of less than 100 ka whereas in others, 36Cl measurements and transient scenarios modelling suggest a longer residence time (>500 ka). In this study, most of the 14C measurements are below the limit of detection, establishing residence times greater than 40 ka and confirming the necessity of strict sampling protocols to exclude all air and AMS measurements when low 14C concentrations are expected. In the Tunisian recharge area, detectable 14C indicate sporadic recharge episodes (3-7 ka and 29-43 ka), whereas 4He and 36Cl concentrations in central areas suggest very old (water quality in the whole system.

  12. Bomb pulse radiocarbon dating

    International Nuclear Information System (INIS)

    Tuniz, C.; Zoppi, U.; Hotchkis, M.A.C.

    2004-01-01

    Modern forensic science has to deal not only with homicides and other traditional crimes but also with more global threats such as the smuggling of nuclear materials, clandestine production of weapons of mass destruction, stockpiling of illicit drugs by state controlled groups and war crimes. Forensic applications have always benefited from the use of advanced analytical tools that can characterize materials found at crime scenes. In this paper we will discuss the use of accelerator mass spectrometry (AMS) as an ultrasensitive tool for the crime laboratories of the third millennium. An important objective in forensic science is to order past events chronologically by analysing materials associated with criminal actions. Radiocarbon dating is known to the general public for its application to historical and prehistorical investigations. Examples of forensic significance include the assassination of the Inca Atahualpa by Francisco Pizarro in the early 1530s, the possible murder of the Tyrolean Ice Man (Oetzi) 5300 years ago and the analysis of the burial cloths allegedly associated with the crucifixion of Jesus Christ . Recent murders, including those associated with war crimes in the Balkans during the 1990s, can be studied using 14 C bomb pulse dating. This method has other forensic applications, including investigation of frauds related to food and wine counterfeiting, dating of opium crops and dating of substances used in biological warfare. AMS extends the applicability of the radiocarbon method, allowing the analysis of 14 C in submilligram organic samples. Specific molecular compounds extracted from bones, hair, skin and other carbon bearing substances of forensic significance can now be dated, enhancing the sensitivity and reliability of chronological determinations. AMS can also be used to analyse rare actinide isotopes released into the environment during the clandestine production of nuclear weapons or associated with the smuggling of nuclear materials. In

  13. Radioactive waste with 14C in Argentina

    International Nuclear Information System (INIS)

    Di Lello, D.S.

    2009-01-01

    14 C is a long half-life radioisotope, which is present in radioactive waste generated during the operation and decommissioning of nuclear power plants. 14 C can also be found in waste generated by medical diagnostic laboratories or any one generated by fields that deal with research and development (mainly connected with the biochemists area). According to international precedents the disposal of 14 C based on the final amount found in radioactive waste and its chemical form have conditioned the design and operation of the facilities (either because of the amount of it or the chemical form in which 14 C was present). We have to take into account that the design of facilities for radioactive waste disposal is included among the obligations of the National Radioactive Waste Management Program (PNGRR). It is absolutely necessary to count with enough information about the characteristics of any waste containing 14 C that is generated in Argentina, in order to be able to fulfil the requirements previously mentioned. The main characteristics of interest in the frame of the present project are: a) the principal reactions that take place for the formation of 14 C; b) The specific concentration of activity in materials where this radio nuclei is formed or is accumulated; c) To know which is the current step in the process of managing these wastes (in Argentina and all over the world). Either if it refers to bulk or conditioned storage, inside the generating facility; d) Transportation possibilities of 14 C under these conditions; e) The accumulated volume and the generation rate of this kind of waste in Argentina. This paper presents an initial collection and evaluation of the information related to the characteristics already mentioned, having gathered published material from the literature and information in the PNGRR up to this moment. The description of the characteristics of the radioactive waste containing 14 C from nuclear power plants, hospitals and research and

  14. {sup 14}C content in aerosols in Mexico City

    Energy Technology Data Exchange (ETDEWEB)

    Gómez, V.; Solís, C.; Chávez, E.; Andrade, E.; Ortiz, M.E.; Huerta, A.; Aragón, J.; Rodríguez-Ceja, M. [Instituto de Física, Universidad Nacional Autónoma de México, Apartado Postal 20-364, México, D.F. 01000 (Mexico); Martínez, M.A. [Facultad de Ciencias, Universidad Nacional Autónoma de México (Mexico); Ortiz, E. [Universidad Autónoma Metropolitana-Azcapotzalco, Av. San Pablo 180, C. P. 02200 México, D.F. (Mexico)

    2016-03-15

    {sup 14}C-AMS of total carbon was determined in aerosols (PM{sub 10} fraction), collected in Mexico City during two weeks from 21 November to 3 December 2012. Other tracers such as total carbon (TC), organic carbon (OC), elemental carbon (EC) and trace element contents were also determined. F{sup 14}C values varied from 0.39 to 0.48 with an average of 0.43. These values are slightly lower than those previously obtained for PM{sub 2.5} in 2003 and 2006 and reflect a high contribution of fossil CO{sub 2} to the carbonaceous matter in aerosols from Mexico City. In contrast, from 2006 to 2012 PM{sub 10} increased; EC, Ca, Ti and Fe concentrations remained constant, while OC, TC and K concentrations decreased. The use of potassium as an indicator of biomass burning showed that this source was negligible during this campaign. Combined analytical approaches allowed us to distinguish temporal variations of anthropogenic and natural inputs to the F{sup 14}C.

  15. Tritium AMS for biomedical applications

    International Nuclear Information System (INIS)

    Roberts, M.L.; Velsko, C.; Turteltaub, K.W.

    1993-08-01

    We are developing 3 H-AMS to measure 3 H activity of mg-sized biological samples. LLNL has already successfully applied 14 C AMS to a variety of problems in the area of biomedical research. Development of 3 H AMS would greatly complement these studies. The ability to perform 3 H AMS measurements at sensitivities equivalent to those obtained for 14 C will allow us to perform experiments using compounds that are not readily available in 14 C-tagged form. A 3 H capability would also allow us to perform unique double-labeling experiments in which we learn the fate, distribution, and metabolism of separate fractions of biological compounds

  16. Placental transfer of 14C-hexoprenaline

    International Nuclear Information System (INIS)

    Lipshitz, J.; Broyles, K.; Whybrew, W.D.; Ahokas, R.A.; Anderson, G.D.

    1982-01-01

    The placental transfer of a single intravenous injection of 14 C-hexoprenaline was studied in eight pregnant New Zealand white rabbits. Maternal and fetal blood was sampled intermittently for 60 minutes after the injection. An initial rapid decrease in the levels of 14 C-hexoprenaline in maternal blood was followed by a second slower phase, whereas fetal heart rate after the administration of a single maternal intravenous injection of hexoprenaline in the treatment of fetal distress is due to the action on the uterus and/or on maternal cardiovascular function, and not to direct stimulation of the fetus

  17. Organic compounds preparation with 14 C

    International Nuclear Information System (INIS)

    Shirvani, Gholam Hossein.

    1996-09-01

    Active urea is a basic reagent for the synthesis of active uric-8- 14 C acid. In our manner, activated Barium carbonate with specified activity was placed in a special furnace with ability of passing gases. Then, ammonia gas was passed through it at about 850 Degree C to obtain Barium Cyanamide. Reaction of the produced compound with CO 2 , and then acidification of the mixture, gave activated urea. Condensation of the urea with Ethylcyanoacetate, produce 6-Aminouracil which upon nitrosation, reduction and then condensation with urea, the desired Uric-8- 14 C acid was synthesized. (author). 148 refs.,

  18. Synthesis of 14C-labeled stepholidine

    International Nuclear Information System (INIS)

    Yang Liu; Zhang Xin

    1988-01-01

    L-Tetrahydroprotoberberine (THPB) alkaloids are dopamine-receptor antagonists. Stepholidine has been shown to possess the strongest pharmacological effects among the THPB alkaloids studied. In order to study its metabolism and the mode of action of the drug, a radiolabeled stepholidine was required. We report here the synthesis of 14 C-labeled stepholidine by Mannich condensation of 7-benzyloxy-1-(4-benzyloxy-3-hydroxy-benzyl)-6-methoxy-1,2,3,4-tetrahydroisoquinoline with ( 14 C)formaldehyde followed by methylation and debensylation in 32% radiochemical yield. (author)

  19. 14C Behaviour in PWR coolant

    International Nuclear Information System (INIS)

    Sims, Howard; Dickinson Shirley; Garbett, Keith

    2012-09-01

    Although 14 C is produced in relatively small amounts in PWR coolant, it is important to know its fate, for example whether it is released by gaseous discharge, removed by absorption on ion exchange (IX) resins or deposited on the fuel pin surfaces. 14 C can exist in a range of possible chemical forms: inorganic carbon compounds (probably mainly CO 2 ), elemental carbon, and organic compounds such as hydrocarbons. This paper presents results from a preliminary survey of the possible reactions of 14 C in PWR coolant. The main conclusions of the study are: - A combination of thermal and radiolytic reactions controls the chemistry of 14 C in reactor coolant. A simple chemical kinetic model predicts that CH 3 OH would be the initial product from radiolytic reactions of 14 C following its formation from 17 O. CH 3 OH is predicted to arise as a result of reactions of OH . with CH 4 and CH 3 , and it persists because there is no known radiation chemical reduction mechanism. - Thermodynamic considerations show that CH 3 OH can be thermally reduced to CH 4 in PWR conditions, although formation of CO 2 from small organics is the most thermodynamically favourable outcome. Such reactions could be catalysed on active nickel surfaces in the primary circuit. - Limited plant data would suggest that CH 4 is the dominant form in PWR and CO 2 in BWR. This implies that radiation chemistry may be important in determining the speciation. - Addition of acetate does not affect the amount of 14 C formed, but the addition of large amounts of stable carbon would lead to a large range of additional products, some of which would be expected to deposit on fuel pin surfaces as high molecular weight hydrocarbons. However, the subsequent thermal decomposition reactions of these products are not known. - Acetate addition may represent a small input of 12 C compared with organic material released from CVCS resins, although the importance of this may depend on whether that is predominantly soluble

  20. Disposition of 14C-β-carotene following delivery with autologous triacylglyceride-rich lipoproteins

    International Nuclear Information System (INIS)

    Dueker, Stephen R.; Le Thuy Vuong; Faulkner, Brian; Buchholz, Bruce A.; Vogel, John S.

    2007-01-01

    Following ingestion, a fraction of β-carotene is cleaved into vitamin A in the intestine, while another is absorbed intact and distributed among tissues and organs. The extent to which this absorbed β-carotene serves as a source of vitamin A is unknown in vivo. In the present study we use the attomole sensitivity of accelerator mass spectrometry (AMS) for 14 C to quantify the disposition of 14 C-β-carotene (930 ng; 60.4 nCi of activity) after intravenous injection with an autologous triacylglyceride-rich lipoprotein fraction in a single volunteer. Total 14 C was quantified in serial plasma samples and also in triglyceride-rich, and low density lipoprotein, subfractions. The appearance of 14 C-retinol, the circulating form of vitamin A in plasma, was determined by chromatographic separation of plasma retinol extracts prior to AMS analysis. The data showed that 14 C concentrations rapidly decayed within the triglyceride-rich lipoprotein fractions after injection, whereas low density lipoprotein 14 C began a significant rise in 14 C 5 h post dose. Plasma 14 C-retinol also appeared at 5 h post dose and its concentrations were maintained above baseline for >88 days. Based upon comparisons of 14 C-retinol concentrations following an earlier study with orally dosed 14 C-β-carotene, a molar vitamin A value of the absorbed β-carotene of 0.19 was derived, meaning that 1 mole of absorbed β-carotene provides 0.19 moles of vitamin A. This is the first study to show that infused β-carotene contributes to the vitamin A economy in humans in vivo

  1. 14C tebuconazole degradation in Colombian soils.

    Science.gov (United States)

    Mosquera, C S; Martínez, M J; Guerrero, J A

    2010-01-01

    Tebuconazole is a fungicide used on onion crops (Allium Fistulosum L) in Colombia. Persistence of pesticides in soils is characterized by the half-life (DT50), which is influenced by their chemical structure, the physical and chemical properties of the soil and the previous soil history. Based on its structural and chemical properties, tebuconazole should be expected to be relatively persistent in soils. Laboratory incubation studies were conducted to evaluate persistence and bond residues of 14C tebuconazole in three soils, two inceptisol (I) and one histosol (H). Textural classifications were: loam (101), loamy sand (102) and loam (H03), respectively. Data obtained followed a first-order degradation kinetics (R2 > or = 0.899) with DT50 values between 158 and 198 days. The production of 14CO2 from the 14C-ring-labelled test chemicals was very low and increased slightly during 63 days in all cases. The methanol extractable 14C-residues were higher than aqueous ones and both decreased over incubation time for the three soils. The formation of bound 14C-residues increased with time and final values were 11.3; 5.55 and 7.87% for 101, 102 and H03 respectively. Soil 101 showed the lowest mineralization rate and the highest bound residues formation, which might be explained by the clay fraction content. In contrast, an inverse behavior was found for soils 102 and H03, these results might be explained by the higher soil organic carbon content.

  2. Synthesis of /sup 14/C-labeled felbamate from phenylacetic-(methylene-/sup 14/C) acid

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Y.M.; Kucharczyk, N.; Sofia, R.D.

    1986-05-01

    A synthetic procedure for the preparation of 2-phenyl-1,3-propanediol-2-/sup 14/C dicarbamate, starting with phenylacetic-(methylene-/sup 14/C) acid was developed. The procedure from phenylacetic acid to 2-phenyl-1,3-propanediol dicarbamate has four steps via phenylmalonic acid and 2-phenyl-1,3-propanediol. The overall yield of all four steps was 28%.

  3. Study of the reaction 14 C (p,p) 14 C

    International Nuclear Information System (INIS)

    Murillo, G.; Ramirez, J.; Avila, O.; Fernandez, M.; Darden, S.E.; Prior, R.P.; Sen, S.

    1991-04-01

    The study of the elastic scattering of polarized protons in 14 C, it has been very limited. Some angular distributions exists to low energy, as well as measures of excitation functions to several angles for the differential section and the vectorial analyzer power. A detailed study of the elastic scattering of protons by 14 C, it give us experimental information of the excited states in 15 N. The study of these states, is since of considerable interest it is not very easy to obtain a target of 14 C also in a reaction 14 C (p,p) 14 C is possible to obtain information of levels in 15 N to an excitation energy E X >14.95 MeV. (Author)

  4. Observational infant exploratory [14C]-paracetamol pharmacokinetic microdose/therapeutic dose study with accelerator mass spectrometry bioanalysis

    NARCIS (Netherlands)

    Garner, C.R.; Park, K.B.; French, N.S.; Earnshaw, C.; Schipani, A.; Selby, A.M.; Byrne, L.; Siner, S.; Crawley, F.P.; Vaes, W.H.J.; Duijn, E. van; ligt, R. de; Varendi, H.; Lass, J.; Grynkiewicz, G.; Maruszak, W.; Turner, M.A.

    2015-01-01

    Aims The aims of the study were to compare [14C]-paracetamol ([14C]-PARA) paediatric pharmacokinetics (PK) after administration mixed in a therapeutic dose or an isolated microdose and to develop further and validate accelerator mass spectrometry (AMS) bioanalysis in the 0-2 year old age group.

  5. AMS analyses at ANSTO

    Energy Technology Data Exchange (ETDEWEB)

    Lawson, E.M. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia). Physics Division

    1998-03-01

    The major use of ANTARES is Accelerator Mass Spectrometry (AMS) with {sup 14}C being the most commonly analysed radioisotope - presently about 35 % of the available beam time on ANTARES is used for {sup 14}C measurements. The accelerator measurements are supported by, and dependent on, a strong sample preparation section. The ANTARES AMS facility supports a wide range of investigations into fields such as global climate change, ice cores, oceanography, dendrochronology, anthropology, and classical and Australian archaeology. Described here are some examples of the ways in which AMS has been applied to support research into the archaeology, prehistory and culture of this continent`s indigenous Aboriginal peoples. (author)

  6. AMS analyses at ANSTO

    International Nuclear Information System (INIS)

    Lawson, E.M.

    1998-01-01

    The major use of ANTARES is Accelerator Mass Spectrometry (AMS) with 14 C being the most commonly analysed radioisotope - presently about 35 % of the available beam time on ANTARES is used for 14 C measurements. The accelerator measurements are supported by, and dependent on, a strong sample preparation section. The ANTARES AMS facility supports a wide range of investigations into fields such as global climate change, ice cores, oceanography, dendrochronology, anthropology, and classical and Australian archaeology. Described here are some examples of the ways in which AMS has been applied to support research into the archaeology, prehistory and culture of this continent's indigenous Aboriginal peoples. (author)

  7. Using accelerator mass spectrometry for radiocarbon dating of textiles

    Energy Technology Data Exchange (ETDEWEB)

    Jull, A.J.T.

    1997-12-01

    Since 1981 we have operated an NSF Accelerator Mass Spectrometry (AMS) Facility at the University of Arizona. The AMS method allows us to use very small samples of carbon, <1 mg for radiocarbon dating in contrast to earlier counting techniques. This has opened a vast array of applications of radiocarbon dating that was difficult to do before AMS because of sample size limitations of decay counting. Some of the many applications of AMS include paleoclimatic studies, archaeological research and the age of first settlement of North America by man, dating of art works and artifacts, fall times and terrestrial residence ages of meteorites, production of {sup 14}C in lunar samples by galactic and solar cosmic rays, studies of in situ {sup 14}C produced by cosmic ray spallation in rocks and ice, and studies of {sup 14}C in groundwater dissolved inorganic carbon and dissolved organic carbon. At our laboratory, we have also successfully applied AMS {sup 14}C to dating of many types of textiles, including silks and linens, art works, documents and artifacts fabricated from wood, parchment, ivory, and bone. The results for many of these samples are often important in questions of the authenticity of these works of art and artifacts. Our studies have encompassed a wide range of art works ranging from the Dead Sea Scrolls, the Shroud of Turin, and the Chinese silk trade to the works of Raphael, Rembrandt, and Picasso. Recently, we also dated the Vinland Map, a controversial document that shows the eastern coast of North America apparently using information from Viking voyages.

  8. Concentration and distribution of 14C in aquatic environment around Qinshan nuclear power plant

    International Nuclear Information System (INIS)

    Wang Zhongtang; Guo Qiuju; Hu Dan; Xu Hong

    2015-01-01

    In order to study the concentration and distribution of 14 C in aquatic environment in the vicinity of Qinshan Nuclear Power Plant (NPP) after twenty years' operation, an apparatus extracting dissolved inorganic carbon from water was set up and applied to pretreat the water samples collected around Qinshan NPP. The 14 C concentration was measured by accelerator mass spectrometer (AMS). The results show that the 14 C specific activities in surface seawater samples range from 196.8 to 206.5 Bq/kg 203.4 ± 5.6) Bq/kg in average), which are close to the background. The 14 C concentrations in cooling water discharged from Qinshan NPP are close to the 14 C values in near shore seawater samples out of liquid radioactive effluent discharge period. It can be further concluded that the 14 C discharged previously is diluted and diffused well, and no 14 C enrichment in seawater is found. Also, no obvious increment in the 14 C specific activities of surface water and underground water samples are found between Qinshan NPP region and the reference region. (authors)

  9. Quality of Graphite Target for Biological/Biomedical/Environmental Applications of 14C-Accelerator Mass Spectrometry

    Science.gov (United States)

    2010-01-01

    Catalytic graphitization for 14C-accelerator mass spectrometry (14C-AMS) produced various forms of elemental carbon. Our high-throughput Zn reduction method (C/Fe = 1:5, 500 °C, 3 h) produced the AMS target of graphite-coated iron powder (GCIP), a mix of nongraphitic carbon and Fe3C. Crystallinity of the AMS targets of GCIP (nongraphitic carbon) was increased to turbostratic carbon by raising the C/Fe ratio from 1:5 to 1:1 and the graphitization temperature from 500 to 585 °C. The AMS target of GCIP containing turbostratic carbon had a large isotopic fractionation and a low AMS ion current. The AMS target of GCIP containing turbostratic carbon also yielded less accurate/precise 14C-AMS measurements because of the lower graphitization yield and lower thermal conductivity that were caused by the higher C/Fe ratio of 1:1. On the other hand, the AMS target of GCIP containing nongraphitic carbon had higher graphitization yield and better thermal conductivity over the AMS target of GCIP containing turbostratic carbon due to optimal surface area provided by the iron powder. Finally, graphitization yield and thermal conductivity were stronger determinants (over graphite crystallinity) for accurate/precise/high-throughput biological, biomedical, and environmental14C-AMS applications such as absorption, distribution, metabolism, elimination (ADME), and physiologically based pharmacokinetics (PBPK) of nutrients, drugs, phytochemicals, and environmental chemicals. PMID:20163100

  10. Placental transfer of 14C-hexoprenaline

    International Nuclear Information System (INIS)

    Lipshitz, J.; Broyles, K.; Whybrew, W.D.; Ahokas, R.A.; Anderson, G.D.

    1982-01-01

    The placental transfer of a single intravenous injection of 14C-hexoprenaline was studied in eight pregnant New Zealand white rabbits. Maternal and fetal blood was sampled intermittently for 60 minutes after the injection. An initial rapid decrease in the levels of 14C-hexoprenaline in maternal blood was followed by a second slower phase, whereas fetal levels remained insignificant. The conclusion, therefore, is that the rapid improvement in fetal heart rate after the administration of a single maternal intravenous injection of hexoprenaline in the treatment of fetal distress is due to the action on the uterus and/or on maternal cardiovascular function, and not to direct stimulation of the fetus

  11. 14C2H4: distribution of 14C-labeled tissue metabolites in pea seedlings

    International Nuclear Information System (INIS)

    Giaquinta, R.; Beyer, E. Jr.

    1977-01-01

    The 14 C-metabolite distribution pattern following 14 C 2 H 4 metabolism in intact pea seedlings (Pisum sativum L.) was determined under various conditions. After a 24 hr exposure to 14 C 2 H 4 , the majority of 14 C-metabolites were water-soluble (60-70%) with lesser amounts in the protein (10-15%), lipid (1%), and insoluble (1-2%) fractions. Ion exchange chromatography of the water-soluble components into basic, neutral, and acidic fractions revealed a 50:40:10 distribution, respectively. Chromatography of the neutral fraction revealed two regions of radioactivity (Rf=0.38) and 0.63 which did not cochromatograph with twenty-two known sugars or neutral metabolites. Chromatograms of the basic fraction contained 3 regions of radioactivity. Similar distribution patterns were noted when 14 C 2 H 4 exposure was followed by a 6 hr air chase or when 5% CO 2 , an antagonist of ethylene action, was present during the exposure. Marked differences in the 14 C-metabolite distribution patterns were obtained when 14 CO 2 was substituted for 14 C 2 H 4 . These results indicate that the metabolic pathway involved in ethylene metabolism is different from that involved in intermediately carbon metabolism. (auth.)

  12. Model experiments for {sup 14}C water-age determinations

    Energy Technology Data Exchange (ETDEWEB)

    Wendt, I; Stahl, W; Geyh, M; Fauth, F [Bundesanstalt fuer Bodenforschung, Hannover (Germany)

    1967-05-15

    {sub 2} phase. A correction for the initial {sup 14}C-activity by means of the {delta}{sup 13}C-value is no longer possible, and the reliability of the {sup 14}C-dating method becomes questionable. (author)

  13. 14C measurements in aquifers with methane

    International Nuclear Information System (INIS)

    Barker, J.F.; Fritz, P.; Brown, R.M.

    1978-01-01

    A survey of various groundwater systems indicates that methane is a common trace constituent and occasionally a major carbon species in groundwaters. Thermocatalytic methane had delta 13 CCH 4 > -45% 0 and microbially-produced or biogenic methane had delta 13 CCH 4 0 . Groundwaters containing significant biogenic methane had abnormally heavy delta 13 C values for the inorganic carbon. Thermocatalytic methane had no apparent effect on the inorganic carbon. Because methanogenesis seriously affects the carbon isotope geochemistry of groundwaters, the correction of raw 14 C ages of affected groundwaters must consider these effects. Conceptual models are developed which adjust the 14 C activity of the groundwater for the effects of methanogenesis and for the dilution of carbon present during infiltration by simple dissolution of rock carbonate. These preliminary models are applied to groundwaters from the Alliston sand aquifer where methanogenesis has affected most samples. In this system, methanogenic bacteria using organic matter present in the aquifer matrix as substrate, have added inorganic carbon to the groundwater which has initiated further carbonate rock dissolution. These processes have diluted the inorganic carbon 14 C activity. (orig.) [de

  14. Radiocarbon dating by accelerator mass spectrometry: some recent results and applications

    International Nuclear Information System (INIS)

    Hedges, R.E.M.

    1987-01-01

    14 C differs from other nuclides measured by accelerator mass spectrometry (AMS) in that an extensive database of dates already exists. AMS dates should therefore have comparable accuracy, and the measurement of isotopic ratios to better than 1%, which was an important technical goal, has been reached. The main advantage of being able to date samples 1000 times smaller than previously lies in the extra selectivity that can be employed. This is reflected in the results and applications. Selection can apply at several levels; from objects that formerly contained too little carbon, to the choice of archaeological material, to the extraction of specific chemical compounds from a complex environmental sample. This is particularly useful in removing uncertainty regarding the validity of a date, since a given sample may comprise carbon atoms from different sources each with their own 14 C 'age'. Examples from archaeological and environmental research illustrating these points are given. 14 C dating by AMS differs from conventional radiocarbon dating by having the potential to measure much lower levels of 14 C, and therefore should double the time span of the method. This potential has not yet been realized because of sample contamination effects, and work in progress to reduce these is described. (author)

  15. Metabolic kinetics and biological effects of radiocarbon (14C)

    International Nuclear Information System (INIS)

    Vasilenko, I.Ya.; Osipov, V.A.; Lyaginskaya, A.M.; Bugryshev, P.F.; Istomina, A.G.; Turova, V.I.; Dement'ev, S.I.; Zhorova, E.S.; Mart'yanov, B.M.; Shal'nova, G.A.; Kuz'mina, T.D.; Shebenko, V.A.; Pomerantseva, M.D.; Ramajya, L.K.

    1988-01-01

    Radiocarbon 14 C is one of the most widespread radionuclides. Increased concentration of anthropogenic 14 C in the biosphere is a problem of considerable hygienic and ecological significance. The paper presents the results of comprehensive studies for years on biokinetics of the main 14 C compounds, inorganic (Na H 14 CO 3 , Na 2 14 CO 3 , K 2 14 CO 3 , Ca 14 CO 3 ) as well as organic ( 14 C-glucose, 14 C-succinic acid, 14 C-glucosamine, 14 C-glycine, 14 C-tryptophane, 14 C-valine, 14 C-palmitic acid, 14 C-stearic acid, 14 C-ethyl alcohol, 14 C-methyl alcohol, 14 C-urea), of 14 C as food constituent and of elementary radiocarbon. The 14 C toxicity is investigated for both acute and chronic small doses received by animals. The nuclide's genetic efficiency is assessed. Based on research evidence, the accumulation multiple and equilibrium time are estimated for long-term 14 C intake by humans. The data may be used for setting genetic standards and estimating an anthropogenic increase of 14 C concentration in the environment. The hazard of anthropogenic radiocarbon is assessed with allowance for further development of nuclear power industry. (author)

  16. Chemical characterization and AMS radiocarbon dating of the binder of a prehistoric rock pictograph at Tadrart Acacus, southern west Libya

    Czech Academy of Sciences Publication Activity Database

    Mori, F.; Ponti, R.; Messina, A.; Flieger, Miroslav; Havlíček, Vladimír; Sinibaldi, M.

    2006-01-01

    Roč. 7, - (2006), s. 344-349 ISSN 1296-2074 Institutional research plan: CEZ:AV0Z50200510 Keywords : rock pictograph * libyan sahara * radiocarbon dating Subject RIV: EE - Microbiology, Virology Impact factor: 0.738, year: 2006

  17. Synthesis of 14C analogue of 1,2-diaryl-[2-14C]-pyrroles

    International Nuclear Information System (INIS)

    Saemian, N.; Shirvani, G.; Matloubi, H.

    2007-01-01

    Three 1,2-diaryl pyrroles selective COX-2 inhibitors, 2-(4-fluorophenyl)-5-methyl-1-(4-methylsulfonyl-phenyl)-1H pyrrole, 2-(4-fluorophenyl)-1- [4-(methylsulfonyl) phenyl]-1H-pyrrole and 4-[2-(4-fluorophenyl)-1H-pyrrol-1-yl]benzenesulfon-amide, all three labeled with 14 C in the 2-position were prepared from para-fluoro-benzaldehyde-[carbonyl- 14 C]. (author)

  18. Synthesis of 14C-labelled butoxyethoxyethanol

    International Nuclear Information System (INIS)

    Thijssen, J.B.A.; Janssen, C.G.M.; Verluyten, W.L.M.; Heykants, J.J.P.

    1986-01-01

    Butoxyethoxyethanol, an organic solvent used as carrier in the levamisole pour-on formulation, was synthesized via a Makosza etherification of 1- 14 C-labelled bromobutane with mono tetrahydropyranyl (T.H.P.) protected diethylene glycol and subsequent removal of the T.H.P. protecting group. The compounds' synthetic yield was 88.8%; it had a specific activity of 32.5 mCi/mmol. The reaction product was radiochemically pure (99.6%) according to high-performance liquid chromatography and thin-layer chromatography in three solvent systems. (author)

  19. Lack of tissue renewal in human adult Achilles tendon is revealed by nuclear bomb 14C

    Science.gov (United States)

    Heinemeier, Katja Maria; Schjerling, Peter; Heinemeier, Jan; Magnusson, Stig Peter; Kjaer, Michael

    2013-01-01

    Tendons are often injured and heal poorly. Whether this is caused by a slow tissue turnover is unknown, since existing data provide diverging estimates of tendon protein half-life that range from 2 mo to 200 yr. With the purpose of determining life-long turnover of human tendon tissue, we used the 14C bomb-pulse method. This method takes advantage of the dramatic increase in atmospheric levels of 14C, produced by nuclear bomb tests in 1955–1963, which is reflected in all living organisms. Levels of 14C were measured in 28 forensic samples of Achilles tendon core and 4 skeletal muscle samples (donor birth years 1945–1983) with accelerator mass spectrometry (AMS) and compared to known atmospheric levels to estimate tissue turnover. We found that Achilles tendon tissue retained levels of 14C corresponding to atmospheric levels several decades before tissue sampling, demonstrating a very limited tissue turnover. The tendon concentrations of 14C approximately reflected the atmospheric levels present during the first 17 yr of life, indicating that the tendon core is formed during height growth and is essentially not renewed thereafter. In contrast, 14C levels in muscle indicated continuous turnover. Our observation provides a fundamental premise for understanding tendon function and pathology, and likely explains the poor regenerative capacity of tendon tissue.—Heinemeier, K. M., Schjerling, P., Heinemeier, J., Magnusson, S. P., Kjaer, M. Lack of tissue renewal in human adult Achilles tendon is revealed by nuclear bomb 14C. PMID:23401563

  20. Studies on 14C-extractable residue, 14C-bound residue and mineralization of 14C-labeled chlorsulfuron in soils

    International Nuclear Information System (INIS)

    Ye Qingfu; Sun Jinhe; Qi Wenyuan; Wu Jianmin

    2003-01-01

    The purpose of the present study was to investigate 14 C-extractable residue ( 14 C-ER), 14 C-bound residue ( 14 C-BR) and mineralization of 14 C-labeled chlorsulfuron in soils by using isotope technique. The main factors affecting 14 C-BR formation and the distribution pattern of 14 C-BR in humus were also discussed in details. The results were as follows: (1) The 14 C-ER content of 14 C-chlorsulfuron in seven kinds of soil was positively related to soil pH and negatively related to clay content and organic matter content significantly. Moreover. the decrease rate of 14 C-chlorsulfuron parent compound derived from 14 C-ER in soils followed the first order rate reaction, the half-life in Soil 1-Soil 7 were 13.0, 13.1, 17.7, 133.3, 21.8, 22.1, 33.2 days, respectively. It was concluded that soil pH was the main factor affecting the degradation of 14 C-chlorsulfuron. (2) The 14 C-BR content of 14 C-chlorsulfuron in soils increased sharply with the incubation time during the initial 20 days, then changed slowly with time. However, 14 C-BR content during the whole incubation depended on soil types. The order of 14 C-BR content followed Soil 1 > Soil 2, Soil 5 and Soil 6 > Soil 3 > Soil 7 > Soil 4. The maximum values of 14 C-BR content of 14 C-chlorsulfuron in Soil 1-Soil 7 were 53.3%, 40.9%, 37.8%, 16.4%, 42.5%, 41.0% and 31.3% of applied amount. In addition, the 14 C-BR content of 14 C-chlorsulfuron in soils was negatively related to soil pH significantly, and positively related to the clay content. The soil pH was found to be the main factor affecting BR formation of 14 C-chlorsulfuron among the basic properties of soil. (3) During the whole periods of the incubation, the 14 C-BR of 14 C-chlorsulfuron in soils was mainly distributed in fulvic acid and humin. The relative percent of 14 C-BR in fulvic acid was higher than in humin. While the relative percentage of the 14 C-BR in humic acid only account for 2%. It was suggested that fulvic acid played an important role

  1. Using accelerator mass spectrometry for radiocarbon dating of textiles

    International Nuclear Information System (INIS)

    Jull, A.J.T.

    1997-01-01

    Since 1981 we have operated an NSF Accelerator Mass Spectrometry (AMS) Facility at the University of Arizona. The AMS method allows us to use very small samples of carbon, 14 C in lunar samples by galactic and solar cosmic rays, studies of in situ 14 C produced by cosmic ray spallation in rocks and ice, and studies of 14 C in groundwater dissolved inorganic carbon and dissolved organic carbon. At our laboratory, we have also successfully applied AMS 14 C to dating of many types of textiles, including silks and linens, art works, documents and artifacts fabricated from wood, parchment, ivory, and bone. The results for many of these samples are often important in questions of the authenticity of these works of art and artifacts. Our studies have encompassed a wide range of art works ranging from the Dead Sea Scrolls, the Shroud of Turin, and the Chinese silk trade to the works of Raphael, Rembrandt, and Picasso. Recently, we also dated the Vinland Map, a controversial document that shows the eastern coast of North America apparently using information from Viking voyages

  2. Synthesis of dexamethasone-4-14C

    International Nuclear Information System (INIS)

    Rao, P.N.; Cessac, J.W.; Hill, K.A.

    1982-01-01

    The bismethylenedioxy (BMD) derivative of dexamethasone 2 was silylated with trimethylchlorosilane and imidazole in dimethylformamide to give the 11β-trimethylsilyloxy BMD derivative 3. The Δ 1 -double bond in 3 was hydrogenated over 5% palladium on carbon to give the Δ 4 -3-oxo steroid 4. Oxidation of 4 with potassium permanganate-sodium metaperiodate gave the seco-acid 5 which on subsequent treatment with acetic anhydride; sodium acetate and triethylamine gave the enol-lactone 6. The enol-lactone 6 was reacted with 14 C-methylmagnesium iodide to give an adduct 7a which on heating at reflux with lithium 2,6-di-t-butylphenoxide in dioxane gave the Δ 4 -3-oxo derivative 8. Compound 8 was heated at reflux with m-iodylbenzoic acid and diphenyl diselenide in toluene to give the Δsup(1,4)-3-oxo steroid 9. The protecting BMD and silyl groups were removed in a single step by reaction with aqueous trifluoroacetic acid containing 2N hydrochloric acid at room temperature to give dexamethasone-4- 14 C 10. (author)

  3. Methodological study on exposure date of Tiankeng by AMS measurement of in situ produced cosmogenic {sup 36}Cl

    Energy Technology Data Exchange (ETDEWEB)

    Dong Kejun [China Institute of Atomic Energy, P.O. Box 275(50), Beijing 102413 (China); Li Shizhuo [China Institute of Atomic Energy, P.O. Box 275(50), Beijing 102413 (China); CNNC China North Nuclear Fuel Company Ltd., Baotou 014035 (China); He Ming [China Institute of Atomic Energy, P.O. Box 275(50), Beijing 102413 (China); Sasa, Kimikazu [Tandem Accelerator Complex, University of Tsukuba, Tsukuba, Ibaraki 305-8577 (Japan); Matsushi, Yuki [Disaster Prevention Research Institute, Kyoto University (Japan); Huang Baojian [Institute of Karst Geology, Chinese Academy of Geological Sciences, Guilin 541004 (China); Ruan Xiangdong; Guan Yongjing [College of Physics Science and Technology, Guangxi University, Nanning 530004 (China); Takahashi, Tsutomu [Tandem Accelerator Complex, University of Tsukuba, Tsukuba, Ibaraki 305-8577 (Japan); Sueki, Keisuke [Graduate School of Pure and Applied Sciences, University of Tsukuba (Japan); Li Chaoli; Wu Shaoyong [China Institute of Atomic Energy, P.O. Box 275(50), Beijing 102413 (China); Wang Xianggao [China Institute of Atomic Energy, P.O. Box 275(50), Beijing 102413 (China); Institute of Karst Geology, Chinese Academy of Geological Sciences, Guilin 541004 (China); Shen Hongtao [China Institute of Atomic Energy, P.O. Box 275(50), Beijing 102413 (China); College of Physics and Technology, Guangxi Normal University, Guilin 541004 (China); Nagashima, Yasuo [Tandem Accelerator Complex, University of Tsukuba, Tsukuba, Ibaraki 305-8577 (Japan); Jiang Shan, E-mail: jiangs@ciae.ac.cn [China Institute of Atomic Energy, P.O. Box 275(50), Beijing 102413 (China)

    2013-01-15

    Tiankeng is a typical Karst relief of the late Quaternary Period. Studies on the exposure ages of Tiankeng are very important in geographical research to elucidate the formation condition, the developing process, and the features of biological species. {sup 36}Cl on the surface layer of the rupture cross-section of Tiankeng is largely produced by cosmogenic high-energy neutron induced reactions {sup 40}Ca(n, {alpha}p) and {sup 39}K(n, {alpha}), and has accumulated since the formation of the Tiankeng. Low-energy neutron reaction {sup 35}Cl(n, {gamma}) contributes a small portion of {sup 36}Cl. In this work, the concentration of the cosmogenic {sup 36}Cl in rock samples taken from Dashiwei Tiankeng, Leye County, Guangxi Zhuang Autonomous Region, China, was measured jointly by Accelerator Mass Spectrometry (AMS) laboratories of CIAE and University of Tsukuba in an effort to estimate the formation time (or exposure age) of the Tiankeng. The results show that the exposure time of Da Shiwei Tiankeng is about 26 {+-} 9.6 ka (without erosion correction). The sampling strategy and procedures, experimental set-up, and preliminary results will be presented in detail.

  4. Analysis of 14C-bearing compounds released by the corrosion of irradiated steel using accelerator mass spectrometry.

    Science.gov (United States)

    Cvetković, B Z; Salazar, G; Kunz, D; Szidat, S; Wieland, E

    2018-06-25

    The combination of ion chromatography (IC) with accelerator mass spectrometry (AMS) was developed to determine the speciation of 14C-(radiocarbon) bearing organic compounds in the femto to pico molar concentration range. The development of this compound-specific radiocarbon analysis (CSRA) of carboxylic acids is reported and the application of the method on a leaching solution from neutron-irradiated steel is demonstrated. The background and the dynamic range of the AMS-based method were quantified. On using 14C-labelled standards, the measurements demonstrate the repeatability of the analytical method and the reproducible recovery of the main target carboxylic acids (i.e., acetate, formate, malonate, and oxalate). The detection limit was determined to be in the mid fmol 14C per L level while the dynamic range of the analytical method covers three orders of magnitude from the low fmol to the mid pmol 14C per L level. Cross contamination was found to be negligible during IC fractionation and was accounted for during eluate processing and 14C detection by AMS. The 14C-bearing carboxylates released from an irradiated steel nut into an alkaline leaching solution were analysed using the CSRA-based analytical method with the aim to check the applicability of the approach and develop appropriate sample preparation. The concentrations of 14C-bearing formate and acetate, the main organic corrosion products, were at a low pmol 14C per L level for convenient dimensions of the alkaline leaching experiment which demonstrates that compound-specific 14C AMS is an extremely sensitive analytical method for analysing 14C-bearing compounds. The content of total organic 14C in solution (TO14C) determined by the direct measurement of an aliquot of the leaching solution agrees well with the sum of the 14C concentrations of the individual carboxylates within the uncertainty of the data. Furthermore, the TO14C content is in good agreement with the calculated value using the corrosion rate

  5. The contribution of AMS to geosciences

    International Nuclear Information System (INIS)

    Chivas, A.R.

    1998-01-01

    Full text: This presentation outlines some of the advances in AMS methods with emphasis on Australian examples and measurements using the accelerators at ANSTO and the Australian National University. Perhaps the best known of these techniques is the application of AMS 14 C dating which has the advantage of needing much smaller amounts of sample (typically 14 C determinations by β counting. AMS 14 C has been applied to dating an enormous array of materials including archaeological samples and sites, tree rings, ice cores, banding in coals and circulation and ventilation changes in the world's oceans. An exciting application of the measurement of the rare long-lived isotopes 10 Be, 26 Al and 36 Cl is in the relatively new field of cosmogenic exposure dating. Accumulation of these cosmogenically produced nuclides formed in-situ in exposed rock surfaces is used to estimate both the time of exposure of the rock surface and mean erosion rates. A large variety of landscape-related processes have been successfully addressed including weathering and sediment-transport rates and the ages of glacial retreat, tectonic uplift and lava eruptions. In the field of hydrology, 36 Cl studies of dissolved chloride have been used to successfully estimate the ages of ground waters and trace their origins. The tracing of atmospheric air masses that deliver rain and the origin of Australian salt lakes and continental salinisation using 36 Cl lead to important conclusions on the origin and residence time of chloride in the Australian landscape. The ultimate origin of the bulk of the surficial chloride in Australia is shown to be meteoric, and for the western part of the continent, a mean residence time of about 0.75 Ma pertains. The realisation of the long-term and continuing delivery of salts to the landscape needs recognition in planning strategies to combat salinisations of agricultural areas

  6. A procedure for batch separation of 14C-hexose from 14C-sucrose

    International Nuclear Information System (INIS)

    Tarpley, L.; Vietor, D.M.

    1991-01-01

    This presentation describes a method for separating 14 C-hexose from 14 C-sucrose in extracts of plant tissue. Portions of ethanol extracts are treated with activated charcoal in microcentrifuge tubes. Aliquots are removed, ethanol evaporated and replaced with reaction mixture that phosphorylates hexose (HEPPS, K 2 HPO 4 , Mg(C 2 H 3 O 2 ) 2 , ovalbumen, Na 2 ATP, yeast hexokinase). After a time course, the hexokinase reaction is stopped (slowed considerably) to minimize effects of contamination enzyme activities. The stopping agent used is lyxose, a nonphosphorylable analogue of glucose. The strong anionic charge of phosphate introduced through the hexokinase action results in binding (> 95%) of hexose-phosphate to anion-exchange resin. Sucrose remains unbound (> 95%) in solution. This batch ion-exchange is performed in microcentrifuge tubes to allow many samples to be processed simultaneously. Recovery of radiolabel in extracts is complete (99%), and determinations are repeatable (cv = 23%). This method for routinely separating and quantifying 14 C-hexose and 14 C-sucrose in plant tissue extracts can contribute to the economy and feasibility of studies of 14 C-photoassimilate partitioning to soluble sugars within and among plant tissues

  7. Imaging AMS

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, S.P.H.T. [Univ. of Oxford (United Kingdom)]|[Lawrence Livermore National Lab., CA (United States); Ramsey, C.B.; Hedges, R.E.M. [Univ. of Oxford (United Kingdom)

    1993-12-01

    The benefits of simultaneous high effective mass resolution and large spectrometer acceptance that accelerator mass spectrometry has afforded the bulk analysis of material samples by secondary ion mass spectrometry may also be applied to imaging SIMS. The authors are exploring imaging AMS with the addition to the Oxford {sup 14}C-AMS system of a scanning secondary ion source. It employs a sub micron probe and a separate Cs flood to further increase the useful ion yield. The source has been accommodated on the system by directly injecting sputtered ions into the accelerator without mass analysis. They are detected with a range of devices including new high-bandwidth detectors. Qualitative mass spectra may be easily generated by varying only the post-accelerator analysis magnet. Selected ion signals may be used for imaging. In developing the instrument for bioscience research the authors are establishing its capability for measuring the lighter elements prevalent in biological tissue. Importantly, the machine can map the distributions of radiocarbon labeled compounds with an efficiency of about 1{per_thousand}. A background due to misidentification of non-{sup 14}C ions as a result of the reduced ion mass filtering is too small to hinder high magnification microscopy.

  8. Carbon 14 dating method

    International Nuclear Information System (INIS)

    Fortin, Ph.

    2000-01-01

    This document gives a first introduction to 14 C dating as it is put into practice at the radiocarbon dating centre of Claude-Bernard university (Lyon-1 univ., Villeurbanne, France): general considerations and recalls of nuclear physics; the 14 C dating method; the initial standard activity; the isotopic fractioning; the measurement of samples activity; the liquid-scintillation counters; the calibration and correction of 14 C dates; the preparation of samples; the benzene synthesis; the current applications of the method. (J.S.)

  9. Dating the Lascaux cave gour formation

    International Nuclear Information System (INIS)

    Genty, D.; Touma, M.; Konik, S.; Konik, S.; Valladas, H.; Hellstrom, J.; Moreau, C.; Dumoulin, J.P.; Nouet, J.; Dauphin, Y.; Weil, R.

    2011-01-01

    Lascaux Cave is renowned for its outstanding prehistoric paintings, strikingly well-preserved over about 18,000 yr. While stalagmites and stalactites are almost absent in the cave, there is an extensive calcite flow-stone that covered a large part of the cave until its opening for tourists during the 1950's. The deposit comprises a succession of calcite rims, or 'gours', which allowed seepage water to pond in large areas in the cave. Their possible role in preservation of the cave paintings has often been evoked, but until now this deposit has not been studied in detail. Here, we present 24 new radiocarbon accelerator mass spectrometry (AMS) and 6 uranium-thorium (U-Th) analyses from the calcite of the gours, 4 AMS 14 C dates from charcoals trapped in the calcite, and 4 AMS 14 C analyses on organic matter extracted from the calcite. Combining the calibrated 14 C ages obtained on charcoals and organic matter and U-Th ages from 14 C analyses made on the carbonate, has allowed the calculation of the dead carbon proportion (dcp) of the carbonate deposits. The latter, used with the initial atmospheric 14 C activities reconstructed with the new IntCal09 calibration data, allows high-resolution age estimation of the gour calcite samples and their growth rates. The carbonate deposit grew between 9530 and 6635 yr cal BP (for dcp = 10.7 ± 1.8%; 2 s) or between 8518 and 5489 yr cal BP (for dcp = 20.5 ± 1.9%; 2 s). This coincides with humid periods that can be related to the Atlantic period in Europe and to Sapropel 1 in the eastern Mediterranean Sea. However, geomorphological changes at the cave entrance might also have played a role in the gour development. In the 1940's, when humans entered the cave for the first time since its prehistoric occupation, the calcite gours had already been inactive for several thousand years. (authors)

  10. Bioconversion of α-[14C]Zearalenol and β-[14C]Zearalenol into [14C]Zearalenone by Fusarium roseum Gibbosum

    International Nuclear Information System (INIS)

    Richardson, K.E.; Hagler, W.M. Jr.; Hamilton, P.B.

    1984-01-01

    Cultures of Fusarium roseum Gibbosum on rice were treated with [ 14 C]zearalenone, α-[ 14 C]zearalenol, or β-[ 14 C]zearalenol to determine whether a precursor-product relationship exists among these closely related fungal metabolites. Culture extracts were purified by silica gel column chromatography and fractionated by high-pressure liquid chromatography, and the level of radioactivity was determined. Within 7 days, the β-[ 14 C]zearalenol was converted to zearalenone, and no residual β-[ 14 C]zearalenol was detectable. Most of the α-[ 14 C]zearalenol added was also converted into zearalenone within 14 days. In cultures treated with [ 14 C]zearalenone, no radioactivity was noted in any other components

  11. A decade of AMS at University of Georgia

    Energy Technology Data Exchange (ETDEWEB)

    Culp, Randy, E-mail: rculp@uga.edu [Center for Applied Isotope Studies, University of Georgia, Athens, GA (United States); Noakes, John; Cherkinsky, Alex; Ravi Prasad, G.V.; Dvoracek, Doug [Center for Applied Isotope Studies, University of Georgia, Athens, GA (United States)

    2013-01-15

    In a span of 10 years, University of Georgia's Center for Applied Isotope Studies (CAIS) has transformed itself from principally a liquid scintillation counting (LSC) laboratory to one conducting thousands of accelerator mass spectrometry (AMS) and stable isotope ratio analysis (SIRA) annually. After receiving the first of the NEC compact AMS units in the United States, the CAIS began to meet the demand for {sup 14}C analysis outside the normal realm of most radiocarbon dating laboratories. With industry's support, isotope research continued on an already developing natural products program to authenticate materials origin and process of formation. The CAIS's AMS allowed for the detection of synthetic materials in milligram quantities rather than gram quantities required by LSC and allowed new compound specific SIRA techniques to be directed toward compound specific {sup 14}C measurement. By 2005 the CAIS was one of only a few laboratories accredited to determine bio-base content in industrial fuels and products by both AMS and LSC following ASTM D6866-10 [1]. Since 2001, when our first sample was analyzed by AMS method, both radiocarbon and natural products sample numbers have increased steadily. The advantages of AMS analysis in overall efficiency, cost savings, accuracy, and precision, are detailed here in a review of analytical precision for radiocarbon and natural products analyzed over 10 years of AMS operation. Comparisons are made between natural products and bio-based materials analyzed by both AMS and LSC. Although high precision is not required to authenticate natural products, for the purpose of product comparison with regard to degree of naturalness accurate and precise {sup 14}C measurement is shown to be achievable by both methods.

  12. A decade of AMS at the University of Georgia

    Science.gov (United States)

    Culp, Randy; Noakes, John; Cherkinsky, Alex; Ravi Prasad, G. V.; Dvoracek, Doug

    2013-01-01

    In a span of 10 years, the University of Georgia’s Center for Applied Isotope Studies (CAIS) has transformed itself from principally a liquid scintillation counting (LSC) laboratory to one conducting thousands of accelerator mass spectrometry (AMS) and stable isotope ratio analysis (SIRA) annually. After receiving the first of the NEC compact AMS units in the United States, the CAIS began to meet the demand for 14C analysis outside the normal realm of most radiocarbon dating laboratories. With industry’s support, isotope research continued on an already developing natural products program to authenticate materials origin and process of formation. The CAIS’s AMS allowed for the detection of synthetic materials in milligram quantities rather than gram quantities required by LSC and allowed new compound specific SIRA techniques to be directed toward compound specific 14C measurement. By 2005 the CAIS was one of only a few laboratories accredited to determine bio-base content in industrial fuels and products by both AMS and LSC following ASTM D6866-10 [1]. Since 2001, when our first sample was analyzed by AMS method, both radiocarbon and natural products sample numbers have increased steadily. The advantages of AMS analysis in overall efficiency, cost savings, accuracy, and precision, are detailed here in a review of analytical precision for radiocarbon and natural products analyzed over 10 years of AMS operation. Comparisons are made between natural products and bio-based materials analyzed by both AMS and LSC. Although high precision is not required to authenticate natural products, for the purpose of product comparison with regard to degree of naturalness accurate and precise 14C measurement is shown to be achievable by both methods.

  13. A decade of AMS at University of Georgia

    International Nuclear Information System (INIS)

    Culp, Randy; Noakes, John; Cherkinsky, Alex; Ravi Prasad, G.V.; Dvoracek, Doug

    2013-01-01

    In a span of 10 years, University of Georgia’s Center for Applied Isotope Studies (CAIS) has transformed itself from principally a liquid scintillation counting (LSC) laboratory to one conducting thousands of accelerator mass spectrometry (AMS) and stable isotope ratio analysis (SIRA) annually. After receiving the first of the NEC compact AMS units in the United States, the CAIS began to meet the demand for 14 C analysis outside the normal realm of most radiocarbon dating laboratories. With industry’s support, isotope research continued on an already developing natural products program to authenticate materials origin and process of formation. The CAIS’s AMS allowed for the detection of synthetic materials in milligram quantities rather than gram quantities required by LSC and allowed new compound specific SIRA techniques to be directed toward compound specific 14 C measurement. By 2005 the CAIS was one of only a few laboratories accredited to determine bio-base content in industrial fuels and products by both AMS and LSC following ASTM D6866-10 [1]. Since 2001, when our first sample was analyzed by AMS method, both radiocarbon and natural products sample numbers have increased steadily. The advantages of AMS analysis in overall efficiency, cost savings, accuracy, and precision, are detailed here in a review of analytical precision for radiocarbon and natural products analyzed over 10 years of AMS operation. Comparisons are made between natural products and bio-based materials analyzed by both AMS and LSC. Although high precision is not required to authenticate natural products, for the purpose of product comparison with regard to degree of naturalness accurate and precise 14 C measurement is shown to be achievable by both methods.

  14. Biological AMS at Uppsala University: Status report

    International Nuclear Information System (INIS)

    Salehpour, Mehran; Forsgard, Niklas; Possnert, Goeran

    2010-01-01

    In January 2007 a new research program was initiated at Uppsala University focusing on the biological applications of AMS. We have used a 5 MV Pelletron Tandem accelerator to study biological samples. With Microdosing applications in mind, a variety of measurements have been performed on human blood, plasma and urine that have been labeled with a 14 C-labeled pharmaceutical drug covering a concentration range, spanning 3 orders of magnitude. Furthermore, by studying small sample amounts and low concentrations, we have demonstrated sensitivity in the hundred zeptomole range for a small pharmaceutical substance in human blood. Another application of interest, based on the enhanced 14 C activity from the cold war bomb-peak, is dating of DNA molecules providing fundamental data for the regenerative medicine and stem cell research community. We show data on a sensitive carrier method for measuring the isotopic ratio of small biological sample in the few μgC range.

  15. Quantitation of 14C-oxaliplatin concentrations in human serum samples by using accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Kobayashi, Takeshi; Toyoguchi, Teiko; Kato, Kazuhiro; Tokanai, Fuyuki; Shiraishi, Tadashi

    2013-01-01

    The understanding of human pharmacokinetics is important for development of new drugs. Microdosing studies have been proposed as means of obtaining human pharmacokinetics information at early stages of drug development. Accelerator mass spectrometry (AMS) has high detection sensitivity and is expected to play an important role in microdose trials. In this study, we used the AMS microdosing facility at Yamagata University to measure the concentration of 14 C in 14 C-oxaliplatin-spiked serum samples. The calibration curve of 14 C concentration in serum was linear, and the correlation coefficient was 0.9994. The precision, accuracy, and stability values obtained (freeze and thaw cycles, and short- and long-term stability) satisfied the criteria. The mean background 14 C concentrations in samples of 6 healthy Japanese volunteers were 1.635dpm/mL in blood and 0.56dpm/mL in plasma. These results suggest the suitability of AMS-based quantitation for analyzing samples from microdosing studies. (author)

  16. METABOLISM OF [14C]GA19 AND [14C]GA53 BY ECOTYPES OF ...

    African Journals Online (AJOL)

    ADMIN

    hand, metabolism of [14C]GA53 was very limited in all day-length treatments and during both, day and night periods. ... compounds which are formed by covalent coupling of GAs to .... For each ecotype day-time and night-time metabolism of ...

  17. Synthesis of [methyl-14C]crotonobetaine from DL-[methyl-14C]carnitine

    International Nuclear Information System (INIS)

    Loester, H.; Seim, H.

    1996-01-01

    The causes of carnitine deficiency syndromes are not completely understood, but decomposition of L-carnitine in vivo is likely to be involved. Carnitine is metabolized to γ-butyrobetaine, and crotonobetaine is probably an intermediate in this pathway. To validate experimentally the precursor-product relationship between the three physiologically occuring γ-betaines - L-carnitine, crotonobetaine, γ-butyrobetaine - labelling with stable or radioactive isotopes became necessary. Methyl-labelled carnitine isomers (L(-)-, D(+)- or DL-) or γ-butyrobetaine can be easily synthesized by methylation of 4-amino-3-hydroxybutyric acid isomers or 4-aminobutyric acid, respectively. Because of problems with the 4-aminocrotonic acid, we synthesized labelled crotonbetaine from labelled carnitine. Thus, DL-[methyl- 14 C]carnitine was dehydrated by reaction with concentrated sulfuric acid. After removal of the latter the products were separated and purified by ion exchange chromatography on DOWEX 50 WX8 (200 - 400 mesh) and gradient elution with hydrochloric acid. In addition to the labelled main product [methyl- 14 C]crotonobetaine (yield about 50 %), [methyl- 14 C]glycine betaine and [methyl- 14 C]acetonyl-trimethylammonium (ATMA) were formed. The end products were identified by combined thin layer chromatography/autoradiography and quantified by liquid scintillation counting. (Author)

  18. Synthesis of ethanol {sup 14}C-1; Synthese d'ethanol {sup 14}C-1

    Energy Technology Data Exchange (ETDEWEB)

    Wolff, R E; Pichat, L [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    The direct reduction by LiAlH{sub 4}, of a suspension of anhydrous sodium acetate in tetra-hydro-furfuryl-oxy-tetra-hydro-pyran is described. This study has shown that the ethanol thus obtained is impure and that the yields are erratic. On the contrary the reduction of acetyl chloride 1-{sup 14}C by LiAlH{sub 4}, in 'diethyl carbitol' leads to ethanol 1-{sup 14}C of satisfactory purity with a yield of about 71 percent. (author) [French] Une etude de la reduction directe par LiAlH{sub 4}, de l'acetate de soude anhydre en suspension dans le tetrahydrofurfuryloxytetrahydropyrane est decrite. Cette etude a montre que l'on obtient de l'ethanol souille d'impuretes, avec un rendement variable. Par contre, la reduction du chlorure d'acetyle {sup 14}C-1 par LiAlH{sub 4}, dans le 'diethyl carbitol' conduit a l'ethanol {sup 14}C-1 de purete convenable avec un rendement de l'ordre de 71 pour cent. (auteur)

  19. Chronometric investigations of the Middle to Upper Paleolithic transition in the Zagros Mountains using AMS radiocarbon dating and Bayesian age modelling.

    Science.gov (United States)

    Becerra-Valdivia, Lorena; Douka, Katerina; Comeskey, Daniel; Bazgir, Behrouz; Conard, Nicholas J; Marean, Curtis W; Ollé, Andreu; Otte, Marcel; Tumung, Laxmi; Zeidi, Mohsen; Higham, Thomas F G

    2017-08-01

    The Middle to Upper Paleolithic transition is often linked with a bio-cultural shift involving the dispersal of modern humans outside of Africa, the concomitant replacement of Neanderthals across Eurasia, and the emergence of new technological traditions. The Zagros Mountains region assumes importance in discussions concerning this period as its geographic location is central to all pertinent hominin migration areas, pointing to both east and west. As such, establishing a reliable chronology in the Zagros Mountains is crucial to our understanding of these biological and cultural developments. Political circumstance, coupled with the poor preservation of organic material, has meant that a clear chronological definition of the Middle to Upper Paleolithic transition for the Zagros Mountains region has not yet been achieved. To improve this situation, we have obtained new archaeological samples for AMS radiocarbon dating from three sites: Kobeh Cave, Kaldar Cave, and Ghār-e Boof (Iran). In addition, we have statistically modelled previously published radiocarbon determinations for Yafteh Cave (Iran) and Shanidar Cave (Iraqi Kurdistan), to improve their chronological resolution and enable us to compare the results with the new dataset. Bayesian modelling results suggest that the onset of the Upper Paleolithic in the Zagros Mountains dates to 45,000-40,250 cal BP (68.2% probability). Further chronometric data are required to improve the precision of this age range. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Magnitude of 14C/12C variations based on archaeological samples

    International Nuclear Information System (INIS)

    Kusumgar, S.; Agrawal, D.P.

    1977-01-01

    The magnitude of 14 C/ 12 C variations in the period A.D. 5O0 to 200 B.C. and 370 B.C. to 2900 B.C. is discussed. The 14 C dates of well-dated archaeological samples from India and Egypt do not show any significant divergence from the historical ages. On the other hand, the corrections based on dendrochronological samples show marked deviations for the same time period. A plea is, therefore, made to study old tree samples from Anatolia and Irish bogs and archaeological samples from west Asia to arrive at a more realistic calibration curve. (author)

  1. Convenient synthesis of [2-{sup 14}C]-methylglyoxal bis(guanylhydrazone), [{sup 14}C]-mitoguazone

    Energy Technology Data Exchange (ETDEWEB)

    Burgos, A.; Ellames, G.J. [Sterling Winthrop Research Centre, Alnwick (United Kingdom). Pharmaceuticals Research Div.

    1995-01-01

    [2-{sup 14}C]-Methylglyoxal bis(guanylhydrazone) dihydrochloride, [{sup 14}C]-mitoguazone has been prepared in three steps from potassium[1-{sup 14}C]-acetate in an overall radiochemical yield of 16%. The key steps in this procedure are the formation of the sodium salt of[acetone-2-{sup 14}C]-methylsulfinylacetone, and Pummerer rearrangement to the [{sup 14}C] labelled hermithioacetal, which is trapped with two equivalents of aminoguanidine to afford the desired [{sup 14}C]-mitoguazone. (Author).

  2. Elements in biological AMS

    International Nuclear Information System (INIS)

    Vogel, J.S.; McAninch, J.; Freeman, S.

    1996-08-01

    AMS (Accelerator Mass Spectrometry) provides high detection sensitivity for isotopes whose half-lives are between 10 years and 100 million years. 14 C is the most developed of such isotopes and is used in tracing natural and anthropogenic organic compounds in the Earth's biosphere. Thirty-three elements in the main periodic table and 17 lanthanides or actinides have long lived isotopes, providing potential tracers for research in elemental biochemistry. Overlap of biologically interesting heavy elements and possible AMS tracers is discussed

  3. Rarotonga Radiocarbon (delta 14C) for 1950 to 1997

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Rarotonga coral radiocarbon (14C) timeseries. Coral radiocarbon (Delta-14C) on untreated, low-speed drilled samples. Precision is +/- 4 per mil as documented by an...

  4. Transformation of the herbicide [14C]glufosinate in soils

    International Nuclear Information System (INIS)

    Smith, A.E.

    1989-01-01

    The degradation of 2 μg/g [ 14 C]glufosinate (DL-homoalan-4-ylmethylphosphinic acid) was studied in clay, clay loam, and sandy loam soils at 85% field capacity and at 20 degree C. Over a 4-week period the soils were extracted and analyzed for transformation products by radiochemical and gas chromatographic techniques. In all soils there was release of [ 14 C]carbon dioxide and formation of [ 14 C]-3-(hydroxymethylphosphinyl)propionic acid (MPPA) as major degradation products. Within 21 days, about 55% of the applied 14 C herbicide had been transformed to MPPA in the sandy loam and 19% to [ 14 C]carbon dioxide. After 28 days, approximately 45% of the 14 C herbicide had been transformed to MPPA in the clay and clay loam and 10% released as [ 14 C]carbon dioxide. At all samplings, other 14 C transformation products appeared to be insignificant

  5. Intracavity optogalvanic spectroscopy. An analytical technique for 14C analysis with subattomole sensitivity.

    Science.gov (United States)

    Murnick, Daniel E; Dogru, Ozgur; Ilkmen, Erhan

    2008-07-01

    We show a new ultrasensitive laser-based analytical technique, intracavity optogalvanic spectroscopy, allowing extremely high sensitivity for detection of (14)C-labeled carbon dioxide. Capable of replacing large accelerator mass spectrometers, the technique quantifies attomoles of (14)C in submicrogram samples. Based on the specificity of narrow laser resonances coupled with the sensitivity provided by standing waves in an optical cavity and detection via impedance variations, limits of detection near 10(-15) (14)C/(12)C ratios are obtained. Using a 15-W (14)CO2 laser, a linear calibration with samples from 10(-15) to >1.5 x 10(-12) in (14)C/(12)C ratios, as determined by accelerator mass spectrometry, is demonstrated. Possible applications include microdosing studies in drug development, individualized subtherapeutic tests of drug metabolism, carbon dating and real time monitoring of atmospheric radiocarbon. The method can also be applied to detection of other trace entities.

  6. Origins of the Iberomaurusian in NW Africa: new AMS radiocarbon dating of the Middle and Later Stone Age deposits at Taforalt Cave, Morocco.

    Science.gov (United States)

    Barton, R N E; Bouzouggar, A; Hogue, J T; Lee, S; Collcutt, S N; Ditchfield, P

    2013-09-01

    Recent genetic studies based on the distribution of mtDNA of haplogroup U6 have led to subtly different theories regarding the arrival of modern human populations in North Africa. One proposes that groups of the proto-U6 lineage spread from the Near East to North Africa around 40-45 ka (thousands of years ago), followed by some degree of regional continuity. Another envisages a westward human migration from the Near East, followed by further demographic expansion at ∼22 ka centred on the Maghreb and associated with a microlithic bladelet culture known as the Iberomaurusian. In evaluating these theories, we report on the results of new work on the Middle (MSA) and Later Stone (LSA) Age deposits at Taforalt Cave in Morocco. We present 54 AMS radiocarbon dates on bone and charcoals from a sequence of late MSA and LSA occupation levels of the cave. Using Bayesian modelling we show that an MSA non-Levallois flake industry was present until ∼24.5 ka Cal BP (calibrated years before present), followed by a gap in occupation and the subsequent appearance of an LSA Iberomaurusian industry from at least 21,160 Cal BP. The new dating offers fresh light on theories of continuity versus replacement of populations as presented by the genetic evidence. We examine the implications of these data for interpreting the first appearance of the LSA in the Maghreb and providing comparisons with other dated early blade and bladelet industries in North Africa. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. S-adenosyl-L-(l-14C)-homocysteine

    International Nuclear Information System (INIS)

    Thomas, H.J.; Montgomery, J.A.

    1987-01-01

    S-Adenosyl-L-(1- 14 C)-homocysteine was prepared from commercially available L-(1- 14 C)-methionine by conversion first to S-benzyl-L-(1- 14 C)-homocysteine which upon treatment with sodium in liquid ammonia gave the disodium salt of L-(1- 14 C)-homocysteine. Reaction of this sodium salt with 5'-O-tosyladenosine gave the title compound. (author)

  8. The LLNL AMS facility

    International Nuclear Information System (INIS)

    Roberts, M.L.; Bench, G.S.; Brown, T.A.

    1996-05-01

    The AMS facility at Lawrence Livermore National Laboratory (LLNL) routinely measures the isotopes 3 H, 7 Be, 10 Be, 14 C, 26 Al, 36 Cl, 41 Ca, 59,63 Ni, and 129 I. During the past two years, over 30,000 research samples have been measured. Of these samples, approximately 30% were for 14 C bioscience tracer studies, 45% were 14 C samples for archaeology and the geosciences, and the other isotopes constitute the remaining 25%. During the past two years at LLNL, a significant amount of work has gone into the development of the Projectile X-ray AMS (PXAMS) technique. PXAMS uses induced characteristic x-rays to discriminate against competing atomic isobars. PXAMS has been most fully developed for 63 Ni but shows promise for the measurement of several other long lived isotopes. During the past year LLNL has also conducted an 129 I interlaboratory comparison exercise. Recent hardware changes at the LLNL AMS facility include the installation and testing of a new thermal emission ion source, a new multianode gas ionization detector for general AMS use, re-alignment of the vacuum tank of the first of the two magnets that make up the high energy spectrometer, and a new cryo-vacuum system for the AMS ion source. In addition, they have begun design studies and carried out tests for a new high-resolution injector and a new beamline for heavy element AMS

  9. Improved precision radiocarbon measurements and natural 14C variations around 10.000 cal BP

    International Nuclear Information System (INIS)

    Goslar, T.

    1990-01-01

    The subject of present work, natural radiocarbon variations in the past, is one of the most significant methodological questions of radiocarbon chronology. In the first three chapters, the author discusses problems connected with calibration of conventional radiocarbon dates, and consequences of monitoring the 14 C variations for the research of the changes of geomagnetic field, solar activity and global carbon cycle. Dendrochronological dating, which, in connection with 14 C measurements enables us to reconstruct the radiocarbon variations in the past, is also widely described. Fourth chapter concerns the technical problems of detection 14 C β-activity, especially accounting for proportional counters technique. In the next chapter the author describes results of his own dendrochonological research. Sixth chapter comprises frame discussion of the system for improved precision radiocarbon dating, together with short presentation of equipment, its calibration and analysis of errors. The last chapter gives the reconstruction of the pattern of atmospheric 14 C variations in 300-year period around 10.000 cal BP. It was found that in the last 10.000 years similar pattern repeats periodically. In the end, the author discusses the meaning of negative correlation between 14 C variations and changes of annual tree-ring widths in the oak trunk from Lublinek, for searching the connection between solar activity and climate. (author)

  10. Autoradiographic disposition of [1-methyl-14C]- and [2-14C]caffeine in mice

    International Nuclear Information System (INIS)

    Lachance, M.P.; Marlowe, C.; Waddell, W.J.

    1983-01-01

    Male, C57B1/6J mice received either [1-methyl-14C]caffeine or [2-14C]caffeine via the tail vein at a dose of 0.7 or 11 mg/kg, respectively. At 0.1, 0.33, 1, 3, 9, and 24 hr after treatment, the mice were anesthetized with ether and frozen by immersion in dry ice/hexane. The mice were processed for whole-body autoradiography by the Ullberg technique; this procedure does not allow thawing or contact with solvents. All autoradiographs revealed some retention of radioactivity at early time intervals in the lacrimal glands, seminal vesicle fluid, nasal and olfactory epithelium, and retinal melanocytes. The remaining portion of the animal was densitometrically uniform except for the lower levels noted in the CNS and adipose tissues. Excretion of radioactivity by the liver and kidneys seems to be the major routes of elimination. Localization in the liver at late time intervals was confined principally to the centrilobular region. Late sites of retention, observed only after [1-methyl-14C]caffeine administration, included the pancreas, minor and major salivary glands, splenic red pulp, thymal cortex, bone marrow, and gastrointestinal epithelium. Sites of localization present in both studies included the olfactory epithelium, lacrimal glands, hair follicles, and retinal melanocytes. Further studies are needed to determine whether the localization at these various sites is due to metabolic degradation, active transport, or possibly a specific receptor interaction

  11. Constraining processes of landscape change with combined in situ cosmogenic 14C-10Be analysis

    Science.gov (United States)

    Hippe, Kristina

    2017-10-01

    Reconstructing Quaternary landscape evolution today frequently builds upon cosmogenic-nuclide surface exposure dating. However, the study of complex surface exposure chronologies on the 102-104 years' timescale remains challenging with the commonly used long-lived radionuclides (10Be, 26Al, 36Cl). In glacial settings, key points are the inheritance of nuclides accumulated in a rock surface during a previous exposure episode and (partial) shielding of a rock surface after the main deglaciation event, e.g. during phases of glacier readvance. Combining the short-lived in situ cosmogenic 14C isotope with 10Be dating provides a valuable approach to resolve and quantify complex exposure histories and burial episodes within Lateglacial and Holocene timescales. The first studies applying the in situ14C-10Be pair have demonstrated the great benefit from in situ14C analysis for unravelling complex glacier chronologies in various glacial environments worldwide. Moreover, emerging research on in situ14C in sedimentary systems highlights the capacity of combined in situ14C-10Be analysis to quantify sediment transfer times in fluvial catchments or to constrain changes in surface erosion rates. Nevertheless, further methodological advances are needed to obtain truly routine and widely available in situ14C analysis. Future development in analytical techniques has to focus on improving the analytical reproducibility, reducing the background level and determining more accurate muonic production rates. These improvements should allow extending the field of applications for combined in situ14C-10Be analysis in Earth surface sciences and open up a number of promising applications for dating young sedimentary deposits and the quantification of recent changes in surface erosion dynamics.

  12. Δ14C level of annual plants and fossil fuel derived CO2 distribution across different regions of China

    International Nuclear Information System (INIS)

    Xi, X.T.; Ding, X.F.; Fu, D.P.; Zhou, L.P.; Liu, K.X.

    2013-01-01

    The 14 C level in annual plants is a sensitive tracer for monitoring fossil fuel derived CO 2 in the atmosphere. Corn leave samples were selected from different regions of China, including high mountains in the Tibetan Plateau, grassland in Inner Mongolia, and inland and coastal cities during the summer of 2010. The 14 C/ 12 C ratio of the samples was measured with the NEC compact AMS system at the Institute of Heavy Ion Physics, Peking University. The fossil fuel derived CO 2 was estimated by comparing the measured Δ 14 C values of corn leave samples to background atmospheric Δ 14 C level. The influences of topography, meteorological conditions and carbon cycling processes on the fossil fuel derived CO 2 concentration are considered when interpreting the data. Our results show a clear association of the low Δ 14 C values with regions where human activities are intensive.

  13. {sup 14}C determination in different bio-based products

    Energy Technology Data Exchange (ETDEWEB)

    Santos Arévalo, Francisco-Javier, E-mail: fj.santos@csic.es [Centro Nacional de Aceleradores (Universidad de Sevilla, Consejo Superior de Investigaciones Científicas, Junta de Andalucía), Thomas Alva Edison 7, 41092 Seville (Spain); Gómez Martínez, Isabel; Agulló García, Lidia; Reina Maldonado, María-Teresa [Centro Nacional de Aceleradores (Universidad de Sevilla, Consejo Superior de Investigaciones Científicas, Junta de Andalucía), Thomas Alva Edison 7, 41092 Seville (Spain); García León, Manuel [Centro Nacional de Aceleradores (Universidad de Sevilla, Consejo Superior de Investigaciones Científicas, Junta de Andalucía), Thomas Alva Edison 7, 41092 Seville (Spain); Dpto. de Física Atómica Molecular y Nuclear, Universidad de Sevilla, Reina Mercedes s/n, 41012 Seville (Spain)

    2015-10-15

    Radiocarbon determination can be used as a tool to investigate the presence of biological elements in different bio-based products, such as biodiesel blends. These products may also be produced from fossil materials obtaining the same final molecules, so that composition is chemically indistinguishable. The amount of radiocarbon in these products can reveal how much of these biological elements have been used, usually mixed with petrol derived components, free of {sup 14}C. Some of these products are liquid and thus the handling at the laboratory is not as straightforward as with solid samples. At Centro Nacional de Aceleradores (CNA) we have tested the viability of these samples using a graphitization system coupled to an elemental analyzer used for combustion of the samples, thus avoiding any vacuum process. Samples do not follow any chemical pre-treatment procedure and are directly graphitized. Specific equipment for liquid samples related to the elemental analyzer was tested. Measurement of samples was performed by low-energy AMS at the 1 MV HVEE facility at CNA, paying special attention to background limits and reproducibility during sample preparation.

  14. Synthesis of [methyl-[sup 14]C]-N-methylputrescine

    Energy Technology Data Exchange (ETDEWEB)

    Secor, H.V.; Izac, R.R.; Hassam, S.B.; Frisch, A.F. (Philip Morris Research Center, Richmond, VA (United States))

    1994-05-01

    [Methyl-[sup 14]C]-N-methylputrescine was prepared from [[sup 14]C]methylamine hydrochloride in five steps. Reaction of benzaldehyde and [[sup 14]C]methylamine (10 mCi) followed by catalytic hydrogenation yielded [methyl-[sup 14]C]-N-methylbenzylamine. The key step in this process is the alkylation of [methyl-[sup 14]C]-N-methylbenzylamine in aqueous medium with 4-bromobutyronitrile. The radiochemical purity of the final product after two successive catalytic hydrogenations was in excess of 97%. The radiochemical yields in two successive runs were 26 and 38%, based on starting [[sup 14]C]methylamine, with specific activities of 22 and 23 mCi/mmol, respectively. This sequence provides a convenient and efficient regioselective radiosynthesis of [methyl-[sup 14]C]-N-methylputrescine. (author).

  15. Future directions of the AMS program at Lucas Heights

    Energy Technology Data Exchange (ETDEWEB)

    Tuniz, C. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)

    1998-12-31

    The research program based on the ANTARES AMS spectrometer involves applications of the long-lived radionuclides {sup 14}C, {sup 10}Be, {sup 26}Al, {sup 36}Cl and {sup 129}I in earth sciences and archaeology. Examples of environmental applications of AMS at Lucas Heights include: use of the {sup 14}C bomb pulse to determine the age and age-spread of air trapped in Antarctic ice bubbles, key parameters to study the variability of CO{sub 2} and other greenhouse gases in the past; analyses of {sup 14}C bomb-pulse curves in tree rings from tropical regions and the southern hemisphere to improve our understanding of the carbon cycle and air-sea interactions, important processes for the global climate; analyses of {sup 10}Be and {sup 36}Cl produced in-situ in polished glacial bedrock and moraine boulders from Tasmania, New Zealand and Antarctica, as part of a major national project to unravel the timing of glacial cycles in the southern hemisphere. A recent archaeological application has been the radiocarbon dating of charcoal fragments from the rock shelter at Jinmium in the Northern Territory demonstrating that this site was occupied by Aboriginal people only during the late Holocene. In environmental monitoring, the analysis of {sup 129}I, {sup 14}C and {sup 36}Cl in water specimens from Mururoa and Fangatauga contributed to an IAEA study regarding residual radioactivity in the Pacific after the French nuclear program Extended abstract. 5 refs.

  16. Future directions of the AMS program at Lucas Heights

    International Nuclear Information System (INIS)

    Tuniz, C.

    1998-01-01

    The research program based on the ANTARES AMS spectrometer involves applications of the long-lived radionuclides 14 C, 10 Be, 26 Al, 36 Cl and 129 I in earth sciences and archaeology. Examples of environmental applications of AMS at Lucas Heights include: use of the 14 C bomb pulse to determine the age and age-spread of air trapped in Antarctic ice bubbles, key parameters to study the variability of CO 2 and other greenhouse gases in the past; analyses of 14 C bomb-pulse curves in tree rings from tropical regions and the southern hemisphere to improve our understanding of the carbon cycle and air-sea interactions, important processes for the global climate; analyses of 10 Be and 36 Cl produced in-situ in polished glacial bedrock and moraine boulders from Tasmania, New Zealand and Antarctica, as part of a major national project to unravel the timing of glacial cycles in the southern hemisphere. A recent archaeological application has been the radiocarbon dating of charcoal fragments from the rock shelter at Jinmium in the Northern Territory demonstrating that this site was occupied by Aboriginal people only during the late Holocene. In environmental monitoring, the analysis of 129 I, 14 C and 36 Cl in water specimens from Mururoa and Fangatauga contributed to an IAEA study regarding residual radioactivity in the Pacific after the French nuclear program

  17. E/Q and ME/Q2 interference in the two models of 14C Tandetron systems: towards the 21st century

    International Nuclear Information System (INIS)

    Nadeau, M.-J.; Lee, H.W.; Litherland, A.E.; Purser, K.H.; Zhao, X.-L.

    2004-01-01

    All 14 C accelerator mass spectrometry (AMS) systems exhibit backgrounds mainly from sample contamination and target preparation. The imperfections in the associated mass spectrometric systems are at present lower and near 14 C/C ∼10 -16 . In view of the increased interest in much lower mass spectrometric background, -18 , for the measurement of natural hydrocarbons, a short review of the existing 14 C systems based upon the Tandetron accelerator will be presented

  18. Bioanalysis works in the IAA AMS facility: Comparison of AMS analytical method with LSC method in human mass balance study

    International Nuclear Information System (INIS)

    Miyaoka, Teiji; Isono, Yoshimi; Setani, Kaoru; Sakai, Kumiko; Yamada, Ichimaro; Sato, Yoshiaki; Gunji, Shinobu; Matsui, Takao

    2007-01-01

    Institute of Accelerator Analysis Ltd. (IAA) is the first Contract Research Organization in Japan providing Accelerator Mass Spectrometry (AMS) analysis services for carbon dating and bioanalysis works. The 3 MV AMS machines are maintained by validated analysis methods using multiple control compounds. It is confirmed that these AMS systems have reliabilities and sensitivities enough for each objective. The graphitization of samples for bioanalysis is prepared by our own purification lines including the measurement of total carbon content in the sample automatically. In this paper, we present the use of AMS analysis in human mass balance and metabolism profiling studies with IAA 3 MV AMS, comparing results obtained from the same samples with liquid scintillation counting (LSC). Human samples such as plasma, urine and feces were obtained from four healthy volunteers orally administered a 14 C-labeled drug Y-700, a novel xanthine oxidase inhibitor, of which radioactivity was about 3 MBq (85 μCi). For AMS measurement, these samples were diluted 100-10,000-fold with pure-water or blank samples. The results indicated that AMS method had a good correlation with LSC method (e.g. plasma: r = 0.998, urine: r = 0.997, feces: r = 0.997), and that the drug recovery in the excreta exceeded 92%. The metabolite profiles of plasma, urine and feces obtained with HPLC-AMS corresponded to radio-HPLC results measured at much higher radioactivity level. These results revealed that AMS analysis at IAA is useful to measure 14 C-concentration in bioanalysis studies at very low radioactivity level

  19. Luminescence dating

    International Nuclear Information System (INIS)

    Rieser, U.

    2009-01-01

    The luminescence techniques have evolved over the last 40 years to a powerful dating instrument in archaeology and geoscience. Depending on how the luminescence is stimulated, one distinguishes the phenomena of thermoluminescence (TL), optically stimulated luminescence (OSL) and infrared stimulated luminescence (IRSL). Each of these phenomena has its specific potential for dating various archaeological materals in the time range from medieval back to palaeolithic periods, or, speaking in geological terms, for dating of Holocene and late Pleistocene objects. The OSL and IRSL techniques are sometimes treated together as 'optical dating'. The luminescence techniques differ from other major dating techniques, such as 14 C, essentially by their applicability to inorganic materials, their wide age-range from about 100 years to more than 100,000 years and the kind of datable events which are the last exposure to heat or to light. (author). 10 refs., 3 figs.

  20. Luminescence dating

    International Nuclear Information System (INIS)

    Rieser, U.

    2008-01-01

    The luminescence techniques have evolved over the last 40 years to a powerful dating instrument in archaeology and geoscience. Depending on how the luminescence is stimulated, one distinguishes the phenomena of thermoluminescence (TL), optically stimulated luminescence (OSL) and infrared stimulated luminescence (IRSL). Each of these phenomena has its specific potential for dating various archaeological materals in the time range from medieval back to palaeolithic periods, or, speaking in geological terms, for dating of Holocene and late Pleistocene objects. The OSL and IRSL techniques are sometimes treated together as 'optical dating'. The luminescence techniques differ from other major dating techniques, such as 14 C, essentially by their applicability to inorganic materials, their wide age-range from about 100 years to more than 100,000 years and the kind of datable events which are the last exposure to heat or to light. (author). 10 refs., 3 figs

  1. Luminescence dating

    International Nuclear Information System (INIS)

    Rieser, U.

    2012-01-01

    The luminescence techniques have evolved over the last 40 years to a powerful dating instrument in archaeology and geoscience. Depending on how the luminescence is stimulated, one distinguishes the phenomena of thermoluminescence (TL), optically stimulated luminescence (OSL) and infrared stimulated luminescence (IRSL). Each of these phenomena has its specific potential for dating various archaeological materials in the time range from medieval back to palaeolithic periods, or, speaking in geological terms, for dating of Holocene and late Pleistocene objects. The OSL and IRSL techniques are sometimes treated together as 'optical dating'. The luminescence techniques differ from other major dating techniques, such as 14 C, essentially by their applicability to inorganic materials, their wide age-range from about 100 years to more than 100,000 years and the kind of datable events which are the last exposure to heat or to light. (author). 10 refs., 3 figs.

  2. Luminescence dating

    International Nuclear Information System (INIS)

    Rieser, U.

    2009-01-01

    The luminescence techniques have evolved over the last 40 years to a powerful dating instrument in archaeology and geoscience. Depending on how the luminescence is stimulated, one distinguishes the phenomena of thermoluminescence (TL), optically stimulated luminescence (OSL) and infrared stimulated luminescence (IRSL). Each of these phenomena has its specific potential for dating various archaeological materals in the time range from medieval back to palaeolithic periods, or, speaking in geological terms, for dating of Holocene and late Pleistocene objects. The OSL and IRSL techniques are sometimes treated together as 'optical dating'. The luminescence techniques differ from other major dating techniques, such as 14 C, essentially by their applicability to inorganic materials, their wide age-range from about 100 years to more than 100,000 years and the kind of datable events which are the last exposure to heat or to light. (author). 10 refs., 3 figs

  3. Luminescence dating

    International Nuclear Information System (INIS)

    Rieser, U.

    2013-01-01

    The luminescence techniques have evolved over the last 40 years to a powerful dating instrument in archaeology and geoscience. Depending on how the luminescence is stimulated, one distinguishes the phenomena of thermoluminescence (TL), optically stimulated luminescence (OSL) and infrared stimulated luminescence (IRSL). Each of these phenomena has its specific potential for dating various archaeological materials in the time range from medieval back to palaeolithic periods, or, speaking in geological terms, for dating of Holocene and late Pleistocene objects. The OSL and IRSL techniques are sometimes treated together as 'optical dating'. The luminescence techniques differ from other major dating techniques, such as 14 C, essentially by their applicability to inorganic materials, their wide age-range from about 100 years to more than 100,000 years and the kind of datable events which are the last exposure to heat or to light. (author). 10 refs., 3 figs.

  4. Status of the “new” AMS facility in Trondheim

    Energy Technology Data Exchange (ETDEWEB)

    Nadeau, Marie-Josée; Vaernes, Einar; Svarva, Helene Løvstrand; Larsen, Eiliv; Gulliksen, Steinar [Department of Archaeometry, Norwegian University of Science and Technology, 7491 Trondheim (Norway); Klein, Matthias; Mous, Dirk J.W. [High Voltage Engineering Europa B.V., P.O. Box 99, 3800 AB Amersfoort (Netherlands)

    2015-10-15

    The Radiocarbon Laboratory of the Norwegian University of Science and Technology (NTNU) in Trondheim has a long history, dating back to the 1950s. Its relatively new AMS facility is based on a 1 MV Tandetron from High Voltage Engineering Europa B.V. that is equipped with a hybrid solid/gas SO-110 ion source, a low energy spectrometer supporting sequential injection, a high energy analysis system consisting of a magnet and an electrostatic deflector, allowing insertion of an absorber foil for isobar suppression, and a two dimensional gas ionisation detector (E and ΔE). The system is at present capable of measuring {sup 10}Be, {sup 14}C, and {sup 26}Al and can be easily modified to measure isotopes of higher masses. Acceptance tests results for {sup 10}Be{sup 1+}, {sup 14}C{sup 2+}, {sup 26}Al{sup 1+}, and {sup 26}Al{sup 3+} are presented. The laboratory measures only {sup 14}C at present and the routine procedures are described. The system has demonstrated a very low background (70,000 {sup 14}C years BP or 2·10{sup −16} on Alfa Aesar 40795 graphite powder, −200 mesh, 99.9995%) for {sup 14}C when charge state 2+ is measured and the interference of Li ions in the detector is minimal. Some ion optical peculiarities of the system are also discussed.

  5. Fate of 14C-labelled compounds in marine environment

    International Nuclear Information System (INIS)

    Kale, S.P.; Raghu, K.; Sherkhane, P.D.; Murthy, N.B.K.

    1999-01-01

    Model ecosystems have played an important role in predicting environmental behavior of agrochemicals. The microcosms used in these studies generally include soil units containing usual biotic components common for that ecosystem. In present studies, scope of two such ecosystems has been extended to study the fate of 14 C-labelled pesticides in marine environment. 14 C-labelled pesticides used in these studies were chlorpyrifos, DDT and HCH. Two systems were developed in laboratory simulating marine environment to study the fate of these pesticides. The first system was developed in an all glass aquarium tank with marine sediments, seawater, clams and algae and is referred to as marine ecosystem. The second system was developed to permit the total 14 C-mass balance studies. It contained marine sediments under moist (60% water holding capacity) or flooded conditions and it is referred to as continuous flow system. Fate of 14 C-DDT was studied in marine ecosystem while degradation of 14 C-chlorpyrifos and 14 C-HCH was studied in continuous flow system. 14 C-DDT did not bioaccumulate in clams while at the end of 60 days 50% of the applied 14 C-activity was present in sediment fraction of marine ecosystem. 14 C-HCH degradation showed about 22-26% mineralization while 45-55% of the applied activity was recovered as organic volatiles. No significant bound residues were formed. 14 C-chorpyrifos underwent considerable degradation in marine environment. TCP was the major degradation product. (author)

  6. Behaviour of 14C-sulfadiazine and 14C-difloxacin during manure storage

    International Nuclear Information System (INIS)

    Lamshoeft, Marc; Sukul, Premasis; Zuehlke, Sebastian; Spiteller, Michael

    2010-01-01

    The persistence of sulfadiazine, difloxacin, and their metabolites has been investigated in stored manure. The manure collected from sulfadiazine ( 14 C-SDZ) and difloxacin ( 14 C-DIF) treated pigs contained N-acetylsulfadiazine (Ac-SDZ), 4-hydroxy-SDZ (4-OH-SDZ), and sarafloxacin (SARA) as the main metabolites, respectively along with their parent compounds. Manures were stored separately at 10 o C and 20 o C at various moisture levels. About 96-99% of the radioactivity remained in extractable parent compounds and their metabolites after 150 d of storage. The formation of non-extractable residue and the rate of mineralization were both negligible in manure containing SDZ and DIF. During storage SDZ concentration increased as a result of the deacetylation of Ac-SDZ, whose concentration decreased proportionally. Hence the environmental effects may be underestimated if the parent compound alone is considered for environmental risk assessment. About 11% and 14% of 4-OH-SDZ were lost after 20 and 40 d of storage; thereafter its concentration increased relatively, highlighting hydroxylation of SDZ. DIF degraded very slowly (7% loss after 150 d) during the storage of manure; in contrast the concentration of SARA decreased rapidly (72-90% loss after 150 d). Dilution of manure and storage at higher temperatures for a reasonable period of time enhanced the rate of reactions of SDZ, DIF and their related metabolites.

  7. 14C Carbofuran residue in rice-fish ecosystem model

    International Nuclear Information System (INIS)

    Sumatra, M.; Soekarna, D.; Suhanda; Kuswadi, A.N.

    1988-01-01

    14-C-carbofuran in the form of 14-C-Furada 3G was applied with doses of 0, 2, and 4 g/m2 to a rice-fish ecosystem model consisting of water, soil, rice, plant, and fish (Cyprinus carpio) in tanks of the size 1 m length, 1 m width, and 0.5 m depth. 14-C-carbofuran was released from 14-C-Furadan 3G, entered into the water, absorbed by plant root, and then distributed into the whole plant. A part of the 14-C-carbofuran was absorbed and retained by soil. In both doses of 4 and 2 g/m2, the 14-C-Furadan 3G was toxic to Cyprinus carpio under this experiment condition. (author). 5 refs, 5 figs, 6 tabs

  8. Transfer of 14C to prenatal and neonatal rats from their mothers exposed to 14C compounds by ingestion

    International Nuclear Information System (INIS)

    Takeda, H.; Fuma, S.; Miyamoto, K.; Kuroda, N.; Inaba, J.

    2003-01-01

    The transfer of 14 C through placenta or milk was investigated and the radiation dose to fetal and newborn rats was estimated. Female rats at gestational stages or after delivery were exposed to 14 C in the form of sodium bicarbonate, thymidine and lysine by a single ingestion. Radioactivity in maternal tissues and conceptuses (placenta, fetal membrane and fetus) and in the newborn was determined at various times after ingestion. After exposure to these 14 C compounds, there was no significant difference between the 14 C concentration in the fetus and that in the maternal tissues, suggesting that the placenta has no effect in preventing or accelerating the placental transfer of 14 C. The concentration and content of 14 C in the fetus and newborn were, however, dependent on the chemical form of 14 C and on the prenatal or neonatal stage at the time of ingestion. The result of the dose estimation showed that 14 C-lysine gave significantly higher prenatal and neonatal doses than 14 C-sodium bicarbonate or 14 C-thymidine. (author)

  9. Percutaneous absorption of [14C]DDT and [14C]benzo[a]pyrene from soil

    International Nuclear Information System (INIS)

    Wester, R.C.; Maibach, H.I.; Bucks, D.A.; Sedik, L.; Melendres, J.; Liao, C.; DiZio, S.

    1990-01-01

    The objective was to determine percutaneous absorption of DDT and benzo[a]pyrene in vitro and in vivo from soil into and through skin. Soil (Yolo County 65-California-57-8; 26% sand, 26% clay, 48% silt) was passed through 10-, 20-, and 48-mesh sieves. Soil then retained by 80-mesh was mixed with [14C]-labeled chemical at 10 ppm. Acetone solutions at 10 ppm were prepared for comparative analysis. Human cadaver skin was dermatomed to 500 microns and used in glass diffusion cells with human plasma as the receptor fluid (3 ml/hr flow rate) for a 24-hr skin application time. With acetone vehicle, DDT (18.1 +/- 13.4%) readily penetrated into human skin. Significantly less DDT (1.0 +/- 0.7%) penetrated into human skin from soil. DDT would not partition from human skin into human plasma in the receptor phase (less than 0.1%). With acetone vehicle, benzo[a]pyrene (23.7 +/- 9.7%) readily penetrated into human skin. Significantly less benzo[a]pyrene (1.4 +/- 0.9%) penetrated into human skin from soil. Benzo[a]pyrene would not partition from human skin into human plasma in the receptor phase (less than 0.1%). Substantivity (skin retention) was investigated by applying 14C-labeled chemical to human skin in vitro for only 25 min. After soap and water wash, 16.7 +/- 13.2% of DDT applied in acetone remained absorbed to skin. With soil only 0.25 +/- 0.11% of DDT remained absorbed to skin. After soap and water wash 5.1 +/- 2.1% of benzo[a]pyrene applied in acetone remained absorbed to skin. With soil only 0.14 +/- 0.13% of benzo[a]pyrene remained absorbed to skin

  10. XCAMS: The compact 14C accelerator mass spectrometer extended for 10Be and 26Al at GNS Science, New Zealand

    Science.gov (United States)

    Zondervan, A.; Hauser, T. M.; Kaiser, J.; Kitchen, R. L.; Turnbull, J. C.; West, J. G.

    2015-10-01

    A detailed description is given of the 0.5 MV tandem accelerator mass spectrometry (AMS) system for 10Be, 14C, 26Al, installed in early 2010 at GNS Science, New Zealand. Its design follows that of previously commissioned Compact 14C-only AMS (CAMS) systems based on the Pelletron tandem accelerator. The only basic departure from that design is an extension of the rare-isotope achromat with a 45° magnet and a two-anode gas-ionisation detector, to provide additional filtering for 10Be. Realised performance of the three AMS modes is discussed in terms of acceptance-test scores, 14C Poisson and non-Poisson errors, and 10Be detection limit and sensitivity. Operational details and hardware improvements, such as 10Be beam transport and particle detector setup, are highlighted. Statistics of repeat measurements of all graphitised 14C calibration cathodes since start-up show that 91% of their total uncertainty values are less than 0.3%, indicating that the rare-isotope beamline extension has not affected precision of 14C measurement. For 10Be, the limit of detection in terms of the isotopic abundance ratio 10Be/9Be is 6 × 10-15 at at-1 and the total efficiency of counting atoms in the sample cathode is 1/8500 (0.012%).

  11. Environmental background 14C levels in Japan in 1990s

    International Nuclear Information System (INIS)

    Fuma, Shoichi; Inoue, Yoshikazu; Miyamoto, Kiriko; Takeda, Hiroshi; Iwakura, Tetsuo; Arai, Kiyohiko; Kashida, Yoshihiko; Ichimasa, Yusuke

    2002-01-01

    For assessment of radiation doses due to 14 C released from nuclear facilities, it is necessary to know the background level of environmental 14 C originated from the natural cosmic-ray production and the past atmospheric nuclear weapons tests. The authors selected grapes as an indicator of 14 C levels in the environment including atmosphere, and determined the specific activities of 14 C in ethanol extracted from wine made from grapes cultivated in several prefectures or unknown places in Japan in each year from 1990 to 2000. The specific activities of 14 C were almost uniform all over Japan in each year, though they showed the weak tendency to slightly decrease with increasing population densities in the prefecture where the wine grapes were cultivated. It is considered that this small regional variation in the specific activities of 14 C arose from Suess effect, because population densities can be regarded as an index of the amount of CO 2 emission from fossil-fuel combustion. The specific activities of 14 C gradually decreased in the 1990s. That is, they were 260 mBq/gC in 1990, and became 244 mBq/gC in 2000. This 14 C level in 2000 was still about 7% higher than the pre-bomb level. The decrease in 14 C originated from the past atmospheric nuclear weapons tests could be described by a single exponential function with a half-time of 10.3 years in 1990s. This half-time was shorter than that in the Europe, Canada and the South Pacific. This difference in the decreasing rate between Japan and other countries may be explained by a fact that the amount of CO 2 emission from fossil-fuel combustion continued to increase in Japan in this period. The specific activities of 14 C in wine ethanol determined in this study showed good agreement with those in atmospheric CO 2 predicted by a mathematical model. They were also in the same levels as the 14 C specific activities in atmospheric CO 2 , tree leaves, grass and plant food in Japan and other countries, which were

  12. Root-uptake of {sup 14}C derived from acetic acid and {sup 14}C transfer to rice edible parts

    Energy Technology Data Exchange (ETDEWEB)

    Ogiyama, Shinichi [Office of Biospheric Assessment for Waste Disposal, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba-shi 263-8555 (Japan)], E-mail: ogiyama@nirs.go.jp; Suzuki, Hiroyuki [Graduate School of Pharmaceutical Sciences, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba-shi 263-5522 (Japan); Inubushi, Kazuyuki [Graduate School of Horticulture, Chiba University, 648 Matsudo, Matsudo-shi 271-8510 (Japan); Takeda, Hiroshi; Uchida, Shigeo [Office of Biospheric Assessment for Waste Disposal, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba-shi 263-8555 (Japan)

    2010-02-15

    Three types of culture experiments using paddy rice (Oryza sativa L.) were performed to examine root-uptake of {sup 14}C in the form of acetic acid: double pot experiment (hydroponics), wet culture experiment (submerged sand medium), and chamber experiment (hydroponics and submerged sand medium). The {sup 14}C radioactivity in the plant, mediums, and atmospheric carbon dioxide ({sup 14}CO{sub 2}) in the chamber were determined, and the distribution of {sup 14}C in the plant was visualized using autoradiography. In the double pot experiment, the shoot of the plant and the lower root which was soaked in the culture solution had {sup 14}C radioactivity, but the upper root which did not have contact with the solution had none. There were also {sup 14}C radioactivity in the grains and roots in the wet culture experiment. Results of the chamber experiment showed that {sup 14}CO{sub 2} gas was released from the culture solution in both types of cultures. Results indicated that the {sup 14}C-acetic acid absorbed by rice plant through its root would be very small. Most of the {sup 14}C-acetic acid was transformed into gaseous forms either in the culture solution or rhizosphere. A relatively longer time would be needed to assimilate {sup 14}C derived from acetic acid to grain parts after it was once absorbed by the shoot through the root. Availability of {sup 14}C for the plant in sand culture was considered to be decreased compared with that for the plant in the hydroponics experiment. It was suggested that rice plant absorbed and assimilated {sup 14}C through the plant roots not because of uptake of {sup 14}C-acetic acid but because of uptake of {sup 14}C in gaseous forms such as {sup 14}CO{sub 2}.

  13. Metabolism of [ 14 C]GA 19 and [ 14 C]GA 53 by ecotypes of Betula ...

    African Journals Online (AJOL)

    Continuing with this line of research, we studied the metabolism of 14C-labelled GA19 and GA53. [14C]GA19 and [14C] A53 were applied to the apices of the northern ecotype (67º N) and to the leaves of the southern ecotype (64º N) of Betula pendula Roth. under different photoperiods and at different times in order to ...

  14. Root-uptake of 14C derived from acetic acid and 14C transfer to rice edible parts

    International Nuclear Information System (INIS)

    Ogiyama, Shinichi; Suzuki, Hiroyuki; Inubushi, Kazuyuki; Takeda, Hiroshi; Uchida, Shigeo

    2010-01-01

    Three types of culture experiments using paddy rice (Oryza sativa L.) were performed to examine root-uptake of 14 C in the form of acetic acid: double pot experiment (hydroponics), wet culture experiment (submerged sand medium), and chamber experiment (hydroponics and submerged sand medium). The 14 C radioactivity in the plant, mediums, and atmospheric carbon dioxide ( 14 CO 2 ) in the chamber were determined, and the distribution of 14 C in the plant was visualized using autoradiography. In the double pot experiment, the shoot of the plant and the lower root which was soaked in the culture solution had 14 C radioactivity, but the upper root which did not have contact with the solution had none. There were also 14 C radioactivity in the grains and roots in the wet culture experiment. Results of the chamber experiment showed that 14 CO 2 gas was released from the culture solution in both types of cultures. Results indicated that the 14 C-acetic acid absorbed by rice plant through its root would be very small. Most of the 14 C-acetic acid was transformed into gaseous forms either in the culture solution or rhizosphere. A relatively longer time would be needed to assimilate 14 C derived from acetic acid to grain parts after it was once absorbed by the shoot through the root. Availability of 14 C for the plant in sand culture was considered to be decreased compared with that for the plant in the hydroponics experiment. It was suggested that rice plant absorbed and assimilated 14 C through the plant roots not because of uptake of 14 C-acetic acid but because of uptake of 14 C in gaseous forms such as 14 CO 2 .

  15. Method of preparing D-mannose(U-14C) from glucons(U-14C) separated from natural material

    International Nuclear Information System (INIS)

    Kucar, S.; Zemek, J.; Bilik, V.; Kolina, J.

    1981-01-01

    Glucans(U- 14 C) separated from green or blue-green algae are hydrolysed using diluted mineral acids in the presence of small amounts of molybdate ions to D-glucose(U- 14 C) which, at a temperature of 60 to 100 degC epimerizes to D-mannose(U- 14 C). The epimeric aldoses are separated from the reaction mixture by paper chromatography. (H.S.)

  16. Synthesis of [14C]-62514, a radiolabelled derivative of erythromycin A, via [2-14C]N,N-dimethylethylenediamine

    International Nuclear Information System (INIS)

    Surber, B.W.; Baker, W.R.; Seif, L.

    1991-01-01

    The synthesis of [ 14 C]A-62514, 11-deoxy-11[carboxy(2-dimethylamino-[1- 14 C]ethyl)amino]-6-0-methyl-e rythromycin A 11,12-(cyclic ester), was performed in five steps. The key intermediate, [2- 14 C]N,N-dimethylethyl-enediamine, was obtained in 80% yield by reacting Eschenmoser's salt with K 14 CN and reducing the resulting [1- 14 C]N,N-dimethylglycinonitrile with H 2 and Raney Ni in methanol and ammonium hydroxide. The final product was obtained 97% radiochemically pure in an overall radiochemical yield of 14%, with a specific activity of 39 mCi/mmol. (author)

  17. 14C ages of Omuroyama volcano, Izu Peninsula

    International Nuclear Information System (INIS)

    Saito, Toshihito; Takahashi, Shuichi; Wada, Hideki

    2003-01-01

    A partly carbonized wood trunk was discovered below the Omuroyama tephra covered by a lava, and it was dated to be 3,700±100 y. B.P., by the benzene liquid scintillation method for radiocarbon age determination. We have investigated the circumstance of the discovery of the wood sample based on an interview of the person who collected the sample during his operation of building construction. According to him, the wood specimen was found at 1.5-2 m depth beneath the ground level when the operator removed the massive blackish lava block. This specimen was laid down covered by black sandy pebbles. The size of the wood trunk was 105 cm long and 45 cm and 35 cm along wide and short diameter, respectively. We also revealed the burial environment of the wood to be related with the Omuroyama tephras and lava flow, based on our volcanostratigraphic observation of the surrounding area. The tephras covering the trunk were identified as the Omuroyama tephra B, C, and D, which were defined by Koyano et al. (1996) around this area, and these tephras were covered by the Omuroyama lava flow II (Koyano et al., 1996). The wood trunk was mostly fresh and only its branch was burned. It can be estimated that the trunk has been preserved surrounded by ground water, since several tons of ground water gushed out when the aquifer was opened for construction. On this context, this trunk was buried at the early stage of the volcanism of Omuroyama volcano covered by the tephras, and later also covered by the Omuroyama lava II. We can not conclude that the burned branch is ascribed to direct burning by the Omuroyama lava flow II but this 14 C dating resultant is also concordant all archaeological evidences reported. (author)

  18. Synthesis and characterization of 14C polyvinylphosphonic acid

    International Nuclear Information System (INIS)

    Stringer, O.D.; Charig, A.

    1989-01-01

    Ten mCi of 14 C ethylene was converted to 1.16 mCi of 14 C PVPA by oxidative phosphonation with phosphorus trichloride and molecular oxygen, dehydrohalogenation with triethylamine in ether, polymerization, and hydrolysis. The polymer had a specific activity of 12 uCi/mg and a radiochemical purity over 99%. (Author)

  19. Synthesis of /sup 14/C-labelled milrinone

    Energy Technology Data Exchange (ETDEWEB)

    Duncan, D.R.; Johnston, D.; Andrews, R.S. (Stirling-Winthrop, Alnwick (UK). Research and Development Div.)

    1985-02-01

    A synthetic procedure for producing /sup 14/C-labelled milrinone, a potent new cardiotonic agent, is described. The synthesis was achieved in two steps from 1-(4-pyridyl)propan-2-one utilising (2-/sup 14/C)cyanoacetamide as the source of the radiolabel. The overall chemical yield was 46% and the radiochemical yield 35%.

  20. Synthesis of specific labelled [methyl-14C]sarin

    International Nuclear Information System (INIS)

    Sin-Ren, A.C.; Riggio, G.; Hopff, W.H.; Waser, P.G.

    1988-01-01

    The synthesis of [methyl- 14 C]sarin ([ 14 C]methylphosphono-fluoridic acid 1-methylethyl ester) was accomplished by another approach as for nonlabelled sarin in a tele-conducted reaction vessel. The purity was estimated by IR, GC, and GC-MS and the stability in different media was examined. (author)

  1. The use of 14C ethanolamine as a precursor

    International Nuclear Information System (INIS)

    Madelmont, J.C.; Parry, D.; Godeneche, D.; Duprat, J.

    1985-01-01

    Two new 2 chloroethyl nitrosoureas were labelled on two positions by 14 C starting from Na 14 CN and using 14 C ethanolamine as intermediate, i.e. on the carbon 2 of the 2 chloro ethyl group and on the carbon 2 of the cysteamine part. (author)

  2. Laboratory Experiments to Evaluate Diffusion of 14C into Nevada Test Site Carbonate Aquifer Matrix

    Energy Technology Data Exchange (ETDEWEB)

    Ronald L. Hershey; William Howcroft; Paul W. Reimus

    2003-03-01

    to published velocities. The lower end of the range of 14C correction factors falls within the range of reported velocities. From these results, future experimental studies (both laboratory and field scale) to support 14C groundwater age dating should focus on obtaining better estimates of aquifer properties including matrix and fracture porosities.

  3. Behavior of 14C-BHC residues in rice grain

    International Nuclear Information System (INIS)

    Lee, S.R.; Kim, Y.H.

    1981-01-01

    γ-(U- 14 C)-BHC was applied to rice plants grown in a pot and its fate in the growth, polishing and oil-extraction processes of the grain was investigated. The 14 C-activity was absorbed and translocated widely in the plant and the recovery of applied 14 C-activity in the straw and grain was about 2.8%, of which 9.4% was found in the brown rice. The % partitioning of 14 C-residues in bran and polished rice was 12:88 and that in oil and oilcake was 37:63. Characterization of 14 C-residues the presence of γ-BHC, pentachlorocyclohexene, trichlorobenzene and hydrophilic metabolites, whose proportions were different in the straw and grain. (Author)

  4. Rectal absorption of homatropine [14C] methylbromide in the rat

    International Nuclear Information System (INIS)

    Cramer, M.B.; Cates, L.A.; Clarke, D.E.

    1978-01-01

    Homatropine [ 14 C]methylbromide (HMB- 14 C) was administered to rats by intramuscular injection, oral gavage and rectal suppository. Plasma concentrations of 14 C were measured over the subsequent 12 h. Peak plasma concentrations were higher and achieved more rapidly after rectal administration than by other routes whether HMB- 14 C was administered in a water-soluble suppository base or in aqueous solution. Twelve h after the suppositories were inserted and retained 28% of the 14 C had been excreted in the urine while 56% remained in the large intestine. Unlabelled HMB, given in rectal suppositories to anaesthetized rats, caused prompt blockade of the effects of vagal stimulation on pulse rate and of intravenous acetylcholine on blood pressure. These results confirm the rapid rectal absorption of the drug. (author)

  5. Radiocarbon 14C differentiation of sparkling and carbonated wines

    International Nuclear Information System (INIS)

    Martin, G.E.; Krueger, H.W.; Burggraff, J.M.

    1985-01-01

    Specific 14 C-activities, percent of modern 14 C-activity, and calculated percent of fermentation CO 2 are presented for CO 2 contained in commercial sparkling wines, labeled as champagne or produced by the bulk (charmat) process. These data are given for the production years 1976-1982. The survey encompassed effervescent wines produced in Spain, Italy, West Germany, California, and New York. Addition of synthetic CO 2 to approximately 40 samples represented as sparkling wines was indicated by low 14 C-activities of CO 2 in these wines. Data for 14 C-activity were also presented for the ethanol distilled from sparkling wines for the years 1977-1980. In all cases, the 14 C-activity of ethanol was appropriate to the year of vintage

  6. Synthesis of phenobarbital {sup 14}C - 5 (1964); Synthese du phenobarbital {sup 14}C - 5 (1964)

    Energy Technology Data Exchange (ETDEWEB)

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

    1964-07-01

    Phenobarbital (Luminal), well known as a hypnotic agent, plays also an important role in the medical treatment of epilepsy. With the object of studying the metabolism of this medicament in the living system, the synthesis of phenobarbital marked in position 2 of the pyrimidinic ring has been effected. It has been necessary, in order to carry out to research into the metabolism of this product, to have a phenobarbital marked in position 5 of the pyrimidinic ring. This synthesis, making it possible to introduce C-14 into position 5 of the pyrimidinic ring, consists of seven stages starting from C-14 carboxyl benzoic acid having a specific activity of 25 mc/mM. The melting point of the final product is 172 - 173 deg. C and its specific activity is 11.15 mc/mM. The overall radioactive yield of the pure product, with respect to the original benzoic acid (10 mM) is of the order of 3 per cent. The purity of the product has been controlled by paper chromatography; it is of the order of 99 per cent. (author) [French] Le phenobarbital (Luminal) bien connu comme agent hypnotique, joue egalement un role important dans la medication anti-epileptique. Pour l'etude du metabolisme de ce medicament dans l'organisme vivant, nous avons synthetise le phenobarbital marque en position 2 du cycle pyrimidinique. Afin de poursuivre la recherche du metabolisme de ce produit, il a ete necessaire de disposer du phenobarbital marque en position 5 du cycle. pyrimidinique. Cette synthese, permettant l'introduction du {sup 14}C en position 5 du cycle pyrimidinique, comporte sept etapes, au depart de l'acide benzoique carboxyle {sup 14}C, d'une activite specifique de 25 mc/mM. Point de fusion du produit final: 172 - 173 deg. C Activite specifique: 11,15 mC/mM. Rendement total radioactif du produit pur, par rapport a l'acide benzoique de depart sur 10 mM, de l'ordre de 3 pour cent. La purete du produit a ete controlee par chromatographie sur papier; elle est de l'ordre de 99 pour cent. (auteur)

  7. Myo-inositol-14C, phytic acid-14C and ferric phytate-14C metabolism through microbian action in an andosol soil

    International Nuclear Information System (INIS)

    Gonzalez I, J.

    1977-01-01

    The myo-inositol- 14 C, phytic acid- 14 C and ferric phytate- 14 C compounds were incubated in an andosol soil at 70% of the field capacity and at 36.5 deg C during twelve days. These compounds suffered a microbian oxidation at 14 CO 2 of 61.0, 1.9 and 0% respectively. The fixation of the phytic acid- 14 C was observed through the fast decrease in the metabolism, due to the formation of complexes with the Fe and Al (phytates). The myo-inositol- 14 C metabolism was reduced by a factor of nine at the second incubation day. The following mechanisms were observed in the myo-inositol metabolism: (i) adsorption of the inositol by the soil minerals, (ii) adsorption by humic acids, (iii) myo-inositol phosphorylation and (iv) epimerization of myo-inositol to chiro-inositol. It was found that the (i) and (ii) formation depends on the soil microbian activity. The (i), (ii) and (iii) interactions were considered as possible mechanisms for the inhibition of the myo-inositol microbian oxidation. The inhibition of the myo-inositol oxidation through adsorption or phosphorylation is considered as a chemical blockade for the hydroaxial group, avoiding this way a microbian oxidation stereospecific of this hydroxil group. (author)

  8. The bomb 14C transient in the Pacific Ocean

    Science.gov (United States)

    Rodgers, Keith B.; Schrag, Daniel P.; Cane, Mark A.; Naik, Naomi H.

    2000-04-01

    A modeling study of the bomb 14C transient is presented for the Pacific Ocean. A primitive equation ocean circulation model has been configured for a high-resolution domain that accounts for the Indonesian Throughflow (ITF). Four separate runs were performed: (1) seasonal forcing with 20 Sv of ITF transport, (2) seasonal forcing with 10 Sv of ITF transport, (3) seasonal forcing with no ITF transport, and (4) interannual forcing with 15 Sv of ITF transport. This study has two main objectives. First, it is intended to describe the time evolution of the bomb 14C transient. This serves as a tool with which one can identify the physical processes controlling the evolving bomb 14C distribution in the Pacific thermocline and thus provides an interpretive framework for the database of Δ14C measurements in the Pacific. Second, transient tracers are applied to the physical oceanographic problem of intergyre exchange. This is of importance in furthering our understanding of the potential role of the upper Pacific Ocean in climate variability. We use bomb 14C as a dye tracer of intergyre exchange between the subtropical gyres and the equatorial upwelling regions of the equatorial Pacific. Observations show that while the atmospheric Δ14C signal peaked in the early to mid-1960s, the Δ14C levels in the surface water waters of the subtropical gyres peaked near 1970, and the Δ14C of surface waters in the equatorial Pacific continued to rise through the 1980s. It is shown that the model exhibits skill in representing the large-scale observed features observed for the bomb 14C transient in the Pacific Ocean. The model successfully captures the basin-scale inventories of bomb 14C in the tropics as well as in the extratropics of the North Pacific. For the equatorial Pacific this is attributed to the model's high meridional resolution. The discrepancies in the three-dimensional distribution of bomb 14C between the model and data are discussed within the context of the dynamical

  9. Metabolism of progesterone-4-14C in organ cultures of fetal adrenal glands in the human being

    International Nuclear Information System (INIS)

    Weber, S.

    1979-01-01

    1. In 72 hours of incubation in two subsequent cultures, progesterone-4- 14 C was converted into different corticosteroids and androgenes by using explants of the adrenal glands in organ cultures, which were taken from a male fetus with a crown-to-rump length of 8.5 cm. In the most cases the water-dilutable metabolites are steroidsulfates. 2. The following individual progesterone metabolites were found: 17α-hydroxyprogesterone-4- 14 C, 16α-hydroxyprogesterone-4- 14 C, corticosterone-4- 14 C, cortisole-4- 14 C, cortisone-4- 14 C, androstendione-4- 14 C, and 11β-hydroxyandrostendione-4- 14 C. 3. These steroides let appear possible the presence and efficacy of the following enzyme systems: 17α-hydroxylase, 16α-hydroxylase, 21-hydroxylase, 11β-hydroxylase, 11β-hydroxysteroide-dehydrogenase, and Csub(17-20) desmolase. 4. Calculations of our dates by the analogue computer, which are present by now, apparently seem to render possible the kinetic of the corticosteroide biosynthesis in the tissue of fetal adrenal glands by organ cultures, because under the present conditions incubations can be carried out for considerably longer periods than by cell fractions, cell homogenates, and organ sections. (orig.) [de

  10. Biokinetics and radiation dosimetry of 14C-labelled triolein, urea, glycocholic acid and xylose in man. Studies related to nuclear medicine 'breath tests' using accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Gunnarsson, Mikael

    2002-08-01

    14 C-labelled substances have been used in biomedical research and clinical medicine for over 50 years. Physicians and scientists however, often hesitate to use these substances in patients and volunteers because the radiation dosimetry is unclear. In this work detailed long-term biokinetic and dosimetric estimation have been carried out for four clinically used 14 C-breath tests: 14 C-triolein (examination of fat malabsorption), urea (detection of Helicobacter pylori infection in the stomach), glycocholic acid and xylose (examination of bacterial overgrowth in the small intestine) by using the highly sensitive accelerator mass-spectrometry (AMS) technique. The AMS technique has been used to measure low 14 C concentrations in small samples of exhaled air, urine, faeces and tissue samples and has improved the base for the estimation of the absorbed dose to various organs and tissues and the effective dose to man. The high sensitivity of the AMS system has also made it possible to perform 14 C breath tests on patient groups which were earlier subject for restriction (e.g. small children). In summary, our results show that for adult patients - and in the case of 14 C-urea breath test also for children down to 3 years of age - the dose contributions are comparatively low, both described as organ doses and as effective doses. For adults, the latter is: 14 C-glycocholic acid - 0.4 mSv/MBq, 14 C-triolein - 0.3 mSv/MBq, 14 C-xylose - 0.1 mSv/MBq and 14 C-urea - 0.04 mSv/MBq. Thus, from a radiation protection point of view there is no reason for restrictions in using any of the 14 C-labelled radiopharmaceutical included in this work in the activities normally used (0.07-0.2 MBq for a 70 kg patient)

  11. Effects of Pseudomonas species on the release of bound 14C residues from soil treated with [14C]atrazine

    International Nuclear Information System (INIS)

    Khan, S.U.; Behki, R.M.

    1990-01-01

    The release of bound (nonextractable) 14 C residues from soil previously treated with [ 14 C]atrazine was investigated by incubation of the solvent-extracted soil with two species of Pseudomonas capable of metabolizing atrazine. The two species, 192 and 194, released bound 14 C residues from the soil. Addition of glucose, known to increase microbiological activities, to the incubated soil appeared to enhance the release of soil-bound 14 C residues, in particular in the presence of Pseudomonas species 192. The 14 C bound residues in soil, mainly present as the parent compound and its hydroxy and monodealkylated analogues, were released into the incubation mixture and were subsequently metabolized by the two species involving dechlorination and dealkylation

  12. Secretin enhances [14C]erythritol clearance in unanesthetized dogs

    International Nuclear Information System (INIS)

    Lewis, M.H.; Baker, A.L.; Dhorajiwala, J.; Moossa, A.R.

    1982-01-01

    To determine the effect of secretin infusion on clearance of inert markers into bile, unanesthetized dogs fitted with Thomas cannulas received continuous infusions of [ 14 C]erythritol and [ 3 H]inulin throughout study. Taurocholic acid administered sequentially at 9.0, 20.0, and 40.0 mumol/min enhanced [ 14 C]erythritol clearance, and GIH secretin (3 units/min) administered along with TCA (40.0 mumol/min) increased [ 14 C]erythritol clearance from 4.9 +/- 1.2 ml/10 min to 6.8 +/- 1.3 ml/10 min (P less than 0.001), but simultaneously measured [ 3 H]inulin clearance was unaltered. Secretin alone also increased [ 14 C]erythritol clearance but did not alter [ 3 H]inulin clearance. The increase in [ 14 C]erythritol clearance per unit increase in bile flow was less during secretin infusion than TCA. Thus, secretin increases [ 14 C]erythritol transport through restricted channels, probably distal to the canaliculi. [ 14 C]Erythritol may not be an accurate marker for canalicular bile flow in dogs during secretin infusion

  13. TMEM14C is required for erythroid mitochondrial heme metabolism.

    Science.gov (United States)

    Yien, Yvette Y; Robledo, Raymond F; Schultz, Iman J; Takahashi-Makise, Naoko; Gwynn, Babette; Bauer, Daniel E; Dass, Abhishek; Yi, Gloria; Li, Liangtao; Hildick-Smith, Gordon J; Cooney, Jeffrey D; Pierce, Eric L; Mohler, Kyla; Dailey, Tamara A; Miyata, Non; Kingsley, Paul D; Garone, Caterina; Hattangadi, Shilpa M; Huang, Hui; Chen, Wen; Keenan, Ellen M; Shah, Dhvanit I; Schlaeger, Thorsten M; DiMauro, Salvatore; Orkin, Stuart H; Cantor, Alan B; Palis, James; Koehler, Carla M; Lodish, Harvey F; Kaplan, Jerry; Ward, Diane M; Dailey, Harry A; Phillips, John D; Peters, Luanne L; Paw, Barry H

    2014-10-01

    The transport and intracellular trafficking of heme biosynthesis intermediates are crucial for hemoglobin production, which is a critical process in developing red cells. Here, we profiled gene expression in terminally differentiating murine fetal liver-derived erythroid cells to identify regulators of heme metabolism. We determined that TMEM14C, an inner mitochondrial membrane protein that is enriched in vertebrate hematopoietic tissues, is essential for erythropoiesis and heme synthesis in vivo and in cultured erythroid cells. In mice, TMEM14C deficiency resulted in porphyrin accumulation in the fetal liver, erythroid maturation arrest, and embryonic lethality due to profound anemia. Protoporphyrin IX synthesis in TMEM14C-deficient erythroid cells was blocked, leading to an accumulation of porphyrin precursors. The heme synthesis defect in TMEM14C-deficient cells was ameliorated with a protoporphyrin IX analog, indicating that TMEM14C primarily functions in the terminal steps of the heme synthesis pathway. Together, our data demonstrate that TMEM14C facilitates the import of protoporphyrinogen IX into the mitochondrial matrix for heme synthesis and subsequent hemoglobin production. Furthermore, the identification of TMEM14C as a protoporphyrinogen IX importer provides a genetic tool for further exploring erythropoiesis and congenital anemias.

  14. Appraisal of the 14C-glycocholate acid test with special reference to the measurement of faecal 14C excretion

    International Nuclear Information System (INIS)

    Scarpello, J.H.B.; Sladen, G.E.

    1977-01-01

    The 14 C-glycocholate test, including the measurement of marker corrected faecal 14 C, has been assessed in the following groups of subjects: normal controls (18), patients with diarrhoea not attributable to altered bile acid metabolism (21), patients with diverticula of the small intestine (12), patients with previous resection of ileum and often proximal colon (34), and established ileostomists (10). Patients with diverticular disease had increased breath 14 CO 2 excretion, but normal faecal excretion of 14 C, and this test was more frequently abnormal than the Schilling test. Ileostomists excreted increased amounts of faecal 14 C, even when the ileum was intact and apparently normal. The pattern after resection was complex. Breath 14 C output was normal if the ileal resection was less than 25 cm in length, although some of these patients had increased faecal 14 C excretion if, in addition, at least 15 cm of proximal colon had been resected or by-passed. Longer ileal resections were associated with increased breath and/or faecal 14 C excretion, depending in part on the length of colon resected or by-passed and the 24 hour faecal volume. Fewer than half these patients had both increased breath and faecal excretion of isotope and faecal 14 C alone was occasionally normal with an ileal resection of 50 cm or more. The 14 C-glycocholate test was more frequently abnormal than the Schilling test in this group. The use of faecal marker correction had only a minor impact on the results. These data suggest that, in patients with ileal resection, faecal 14 C, like faecal weight, is determined by the extent of colonic resection as well as by the amount of ileum resected. (author)

  15. Radiometric dating

    International Nuclear Information System (INIS)

    Das, N.R.

    2017-01-01

    Since the discovery of natural radioactivity in uranium, in the last decade of the nineteenth century, the nuclear property of radioactive decay of radionuclides at immutable rates has been effectively utilized in dating of varieties of naturally occurring geological matrices and the organisms which constantly replenish their "1"4C supply through respiration when alive on earth. During the period, applications of radiometric dating techniques have been extensively diversified and have enabled the geologists to indicate the absolute time scales of geological formations and the evolution of the solar system, the earth, meteorites, lunar rocks, etc. and the archaeologists to record the facts of history of several important events like dinosaur era, Iceman, the Shroud in Turin and many other ancient artefacts. In the development of dating methods, varieties of naturally occurring radio-isotopic systems with favorable half-lives ranging from about 10 years to over 100 billion years have been used as radiometric clocks. (author)

  16. Synthesis of 14C and 32P double labelled triethylphosphine

    International Nuclear Information System (INIS)

    Kanska, M.; Drabarek, S.

    1979-01-01

    The synthesis of 14 C and 32 P double labelled triethylphosphine has been carried out using red phosphorus [ 32 P] and barium carbonate [ 14 C] as starting materials. The product of the reaction has been separated by gas chromatography. The 32 P radioactivity assay of the obtained product was performed by the liquid scintillation technique. The 14 C radioactivity was determined by the liquid scintillation technique and internal gas counting method. The radioactivity measurements have served to determine the total yield of double labelled triethylphosphine. (author)

  17. Method of preparing pyrimidine derivatives universally labelled with 14C

    International Nuclear Information System (INIS)

    Pritasil, L.; Filip, J.

    1976-01-01

    Sodium salts of beta-keto acid ethyl esters having mole activity higher than 40 mCi/milliatom 14 C are condensed with 14 C-thiourea having mole activity higher than 40 mCi/milliatom 14 C. Condensation proceeds in an anhydrous ethanol medium at a 1:1 molar ratio, with a 40 to 50% yield. Under the above reaction conditions, the radiochemical yield is higher than 20% while in biosynthesis it is 1% and in the chemical synthesis it is 10%. (J.P.)

  18. Distribution of 14C, 90Sr and 228Th in an elephant tusk

    International Nuclear Information System (INIS)

    Brunnermeier, M.J.; Schmied, S.A.K. Contact Information and Robert Schupfner

    2012-01-01

    The period of date of death of an elephant can be assessed by analyzing four different radionuclides, 14 C, 90 Sr, 228 Th and 232 Th in its ivory. These nuclides are supposed to have variing concentrations at different parts of a tusk. The reason is the procedure of growth which takes place at the butt-site of a tusk. Therefore the site of sampling could have a big influence on the assessed date of death. However, to find out if the position of sampling is important a complete tusk was analyzed regarding the distribution of these nuclides. Results show that the concentration activity of 14 C and 228 Th varies in different parts of a tusk. The activity concentration of 90 Sr is very similar in all analyzed parts. The conclusion is that sampling at the butt of a tusk is recommended for age assessment. (author)

  19. 41 CFR 301-11.10 - Am I required to record departure/arrival dates and times on my travel claim?

    Science.gov (United States)

    2010-07-01

    ... departure/arrival dates and times on my travel claim? 301-11.10 Section 301-11.10 Public Contracts and... dates and times on my travel claim? You must record the date of departure from, and arrival at, the... visited. You do not have to record departure/arrival times, but you must annotate your travel claim when...

  20. Preparation of D-[U-14C]galactose and α-D-[U-14C]galactose-1-phosphate

    International Nuclear Information System (INIS)

    Kolina, J.; Hromadkova, B.

    1989-01-01

    Optically pure D-[U- 14 C]galactose was prepared on a preparatory scale using the galactokinase enzyme. The suggested procedure allows to also prepare a α-D-[U- 14 C]galactose-1-phosphate and L-[U- 14 ]galactose giving good yield. The experiments proved that the raw fraction isolated from yeast of the Kluyveromyces fragilis strain or the Kluyveromyces lactis strain shows sufficient activity. Phosphorylation of D-[U- 14 C]galactose practically terminates after 30 mins of incubation. DL-[U- 14 C]galactose isolated using preparatory paper chromatography from the acid hydrolyzate of [U- 14 C] polysaccharide is a satisfactory radioactive precursor. The developed preparation procedure theoretically contributed towards the further elucidation of the problem of the proportional representation of galactose stereo-isomers in extracellular polysaccharide isolated from red algae. In this respect data in the literature differ and some sources state a significantly higher propertion of L-galactose. The experiments showed that [U- 14 C] polysaccharide isolated from the red algae Porphyridium cruentum prevalently contains D-[U- 14 C]galactose, which confirms the process of enzyme reaction. (author). 1 tab., 4 refs

  1. Studies on residues of 14C malathion in soils

    International Nuclear Information System (INIS)

    Ghezal, F.; Bennaceur, M.

    1991-04-01

    The extractability, the mobility and formation of bound 14C labelled residues in two soils under normal conditions were investigated with malathion. Comparison is made between irradiated and autoclaved soils. The highest concentration of the product is found in the first section (0-4cm) after experiment. Three compounds were found in the soils. 14C malathion is decomposed to 14C02. The degradation is more important in organic matter rich soil. In rich soil, 50% of 14C product is degradated after 17 days. This percentage is only 10%, for poor soil. The 14CO 2 produced in non-sterile soil is 33,05%. This percentage is respectively 10,92% and 3,57% only for irradiated and autoclaved soils

  2. Measurements of in situ produced 14C in terrestrial rocks

    International Nuclear Information System (INIS)

    Yokoyama, Yusuke; Caffee, Marc W.; Southon, John R.; Nishiizumi, Kunihiko

    2004-01-01

    We developed and are testing a system for extracting in situ produced 14 C from quartz. 14 C is liberated from quartz matrix using step-wise heating during which time a spiked carrier gas consisting O 2 -CO-CO 2 -He is flowed through the high-temperature chamber continuously. The total 14 C background is reproducible and typically (2.3 ± 0.2) x 10 6 atoms, and the recovery is consistently greater than 90%. To validate the performance of the system and determine the blank level, we are using quartz samples taken from the Homestake mine (1600 m below the surface), South Dakota. To determine the 14 C release pattern and recovery, we used samples taken from the Transantarctic Mountains, Antarctica

  3. Determination of phagocytosis in periodontitis postjuvenilis using 14C

    International Nuclear Information System (INIS)

    Zietek, M.

    1990-01-01

    In 20 patients with periodontitis and 10 healthy controls phagocytosis was determined using 14 C-labelled Staphylococcus aureus. The decrease of phagocytosis found in the diseased patients was significant

  4. Synthesis of [14C]-labelled AY-30,068

    International Nuclear Information System (INIS)

    Hicks, D.R.; Hangeland, J.J.; Mobilio, D.; DeLange, B.

    1988-01-01

    [ 14 C]AY-30,068 (cis-1,8-diethyl-2,3,4,9-tetrahydro-4-(2-propenyl)-1H-carbazole-1-acetic acid), a potent analgesic agent, was prepared by incorporating [ 14 C]methyl iodide via a Wittig reaction. The intermediate aldehyde was synthesized in six steps from cis-1-ethyl-2-oxo-4-(2-propenyl)cyclohexaneacetic acid methyl ester. Three batches of the [ 14 C]labelled AY-30,068 were produced, giving a combined overall yield of 9% from [ 14 C]methyl iodide sp. act. 51.2, 17.7 and 4.4 μCi/mg; 97.5, 98.3, and 98.6% radiochemical purity, respectively. (author)

  5. Incorporation of 14C-succinate in Synechococcus

    International Nuclear Information System (INIS)

    Doehler, G.

    1983-01-01

    The cyanobacterium Synechococcus (= Anacystis nidulans) was grown under normal air conditions (0.03 vol.% CO 2 ) and in low white light (0.5 x 10 3 μW/cm 2 ) at 37 0 C. Kinetics of 14 C incorporation into several soluble products and pigments were studied after adding 14 C-succinate during photosynthesis and in the dark using the autoradiographic method. Radioactivity was found mainly in glutamate and aspartate during the photosynthetic period independent on 3-(3',4'-dichlorphenyl)-1,1-dimethylurea preincubation. In the dark period 14 C label could also be detected in malate. Short-term kinetics experiments showed a decrease in 14 C label of glutamate and a parallel increase of aspartate. Results were discussed in respect to the interrupted tricarboxylic acid cycle. (author)

  6. Whole body autoradiography with mice using 14C-thymidine

    International Nuclear Information System (INIS)

    Hruby, R. et al

    1982-06-01

    Whole body autoradiography was performed using common histology equipment. Results were useful with some restrictions. 14C-thymidine and/or itsmetabolites were found in those tissues with high rate of mitosis. (Author)

  7. Genetic consequences of the 14C-decay

    International Nuclear Information System (INIS)

    Gracheva, L.M.; Korolev, V.G.

    1978-03-01

    There are only few investigations on the biological and genetic consequences of 14 C decay especially due to the long half-life of 14 C. Naturally, the consequences of the decay of 14 C incorperated in DNA is of particular interest. Due to the thus occuring conversion into nitrogen, either opening of the ribose residue ring and base occurs or conversion into base analogue. The present work gives a survey on the investigational results on this topic which were obtained by various authors on phages, bacteria, algae and animal cells, as well as on molecular level. It was shown that the transmutation for the occurence of a lethal effect is many times more effective than β-radiation. Investigations of the mutagenic effects and other genetic effects of the 14 C decay were carried out on micro-organisms, however also on higher forms of life, plants, insects and mice. An analysis of the mutations showed that transitions as well as transversions occur. As example for genetic effects of 14 C decay, the two following are named. In the case of mice which were exposed to 14 CO 2 atmosphere, it was seen that the number of polyptoidal chromosome sets in the first spermotacytes increased considerably, an increase of the chromosome conversion rate was however not observed. When treating gryllus larvae with 14 C, it was interesting to note that the crossing of 14 C-contained females with normal males produced viable eggs, whereas normal females after crossing with 14 C contained males, laid no more eggs. (MG) 891 MG [de

  8. Synthesis and analysis of 14C-labelled butyltin compounds

    International Nuclear Information System (INIS)

    Kloetzer, D.

    1976-01-01

    This paper deals with methods for the synthesis of 14 C-labelled analoga of the important biocides tributyltin oxide, tributyltin benzoate, tributyltin salicylate and tributyltin fluoride as well as dibutyltin oxide. The radioactive starting substance butylbromide-1- 14 C is treated with sodium and monobutyltin chloride or tin tetrachloride to form a mixture of radioactive butyltin compounds from which the substance desired is separated. A system satisfactorily meeting the conditions for thin-layer radiochromatography is presented. (author)

  9. Radioactive decay of 223Ra by 14C emission

    International Nuclear Information System (INIS)

    Yashita, S.; Gregorich, K.; Ghiorso, A.

    1985-01-01

    Recently H.J. Rose and G.A. Jones at the University of Oxford reported the very difficult observation of an exotic radioactive decay mode in 233 Ra, its spontaneous disintegration by the emission of 14 C particles. The authors have confirmed their somewhat surprising discovery by an independent method. Within the present experimental accuracy the magnetic rigidity, energy and branching ratio support the assignment of 14 C emission from 223 Ra as proposed by the Oxford experiment

  10. 14C-Metampicillin stability in several physiological sera

    International Nuclear Information System (INIS)

    Jimeno de Osso, F.; Casas Medica, F.; Carriazo Tovar, D.

    1981-01-01

    Degradation of 14 C -metampicillin incorporated to several physiological sera for medical uses has been studied. Influence of environmental conditions as well as possible interaction with the solvent have been specially analyzed. Degradation level of the labelled multiplication has been determined and its degradation products have been separated by using chromatographic and radiochemical methods. Likewise, the 14 C -metam picill synthesis has been described. Finally, the results obtained have been discussed and evaluated. (Author) 9 refs

  11. Clinical investigation of 14C-urea breath test

    International Nuclear Information System (INIS)

    Yu Yongli; Zhu Ruisen; Ji Hong; Luo Quanyong

    2000-01-01

    To investigate clinical value of 14 C-urea breath test ( 14 C-UBT) for the diagnosis of Helicobacter pylori(Hp), 70 patients were both performed gastroscopy (taking gastric mucosae biopsy for rapid urease test and histology) and 14 C-UBT (some patients by Hp-IgG or DNAHp test also) within two days. The positive cases of both rapid urease test and histology was defined as 'gold standard' of Hp-positive, whereas the negative cases of both rapid urease test and histology as 'gold standard' of Hp-negative. The sensitivity of 14 C-UBT was 93.2%, the specificity 73.1%, and the diagnostic accuracy 85.7%. The difference (comparing with 'gold standard') was not marked (x 2 = 0.9 0.05(1) 2 = 3.84, P>0.05). But the diagnostic accuracy of 14 C-UBT (85.7%) and Hp-IgG (50%) had a marked difference (x 2 13.80>x 0.01(1) 2 = 6.64, P 14 C-UBT was easy to operate, reliable and suitable for clinical application

  12. Determining the biomass fraction of mixed waste fuels: A comparison of existing industry and {sup 14}C-based methodologies

    Energy Technology Data Exchange (ETDEWEB)

    Muir, G.K.P., E-mail: Graham.Muir@glasgow.ac.uk [SUERC Radiocarbon Laboratory, Scottish Universities Environmental Research Centre (SUERC), Rankine Avenue, East Kilbride G75 0QF, Scotland (United Kingdom); Hayward, S. [Stopford Energy and Environment, The Gordon Manley Building, Lancaster University, Lancaster LA1 4YQ, England (United Kingdom); Tripney, B.G.; Cook, G.T.; Naysmith, P. [SUERC Radiocarbon Laboratory, Scottish Universities Environmental Research Centre (SUERC), Rankine Avenue, East Kilbride G75 0QF, Scotland (United Kingdom); Herbert, B.M.J. [Stopford Energy and Environment, The Gordon Manley Building, Lancaster University, Lancaster LA1 4YQ, England (United Kingdom); Garnett, M.H [NERC Radiocarbon Facility, Scottish Enterprise Technology Park, Rankine Avenue, East Kilbride G75 0QF, Scotland (United Kingdom); Wilkinson, M. [Stopford Energy and Environment, The Gordon Manley Building, Lancaster University, Lancaster LA1 4YQ, England (United Kingdom)

    2015-01-15

    Highlights: • Compares industry standard and {sup 14}C methods for determining bioenergy content of MSW. • Differences quantified through study at an operational energy from waste plant. • Manual sort and selective dissolution are unreliable measures of feedstock bioenergy. • {sup 14}C methods (esp. AMS) improve precision and reliability of bioenergy determination. • Implications for electricity generators and regulators for award of bio-incentives. - Abstract: {sup 14}C analysis of flue gas by accelerator mass spectrometry (AMS) and liquid scintillation counting (LSC) were used to determine the biomass fraction of mixed waste at an operational energy-from-waste (EfW) plant. Results were converted to bioenergy (% total) using mathematical algorithms and assessed against existing industry methodologies which involve manual sorting and selective dissolution (SD) of feedstock. Simultaneous determinations using flue gas showed excellent agreement: 44.8 ± 2.7% for AMS and 44.6 ± 12.3% for LSC. Comparable bioenergy results were obtained using a feedstock manual sort procedure (41.4%), whilst a procedure based on selective dissolution of representative waste material is reported as 75.5% (no errors quoted). {sup 14}C techniques present significant advantages in data acquisition, precision and reliability for both electricity generator and industry regulator.

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

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  14. 14C emission from Swedish nuclear power plants and its effect on the 14C levels in the environment

    International Nuclear Information System (INIS)

    Stenstroem, K.; Erlandsson, Bengt; Hellborg, R.; Kiisk, M.; Persson, Per; Mattsson, Soeren; Thornberg, C.; Skog, G.

    2000-02-01

    The radionuclide 14 C is produced in all types of nuclear reactors mainly by neutron induced reactions in oxygen ( 17 O), nitrogen ( 14 N) and carbon ( 13 C). Part of the 14 C created is continuously released during normal operation as airborne effluents in various chemical forms (such as CO 2 , CO and hydrocarbons) to the surroundings. Because of the biological importance of carbon and the long physical half-life of 14 C, it is of interest to measure the releases and their incorporation into living material. The 14 C activity concentrations in annual tree rings and air around two Swedish nuclear power plants (Barsebaeck and Forsmark) as well as the background 14 C activity levels from two reference sites in southern Sweden during 1973-1996 are presented in this report. In order to verify the reliability of the method some investigations have been conducted at two foreign nuclear sites, Sellafield fuel reprocessing plant in England, and Pickering nuclear generating station in Canada, where the releases of 14 C are known to be substantial. Furthermore, results from some measurements in the vicinity of Paldiski submarine training centre in Estonia are presented. The results of the 14 C measurements of air, vegetation and annual tree rings around the two Swedish nuclear power plants show very low enhancements of 14 C, if at all above the uncertainty of the measurements. Even if the accuracy of the measurements of the annual tree rings is rather good (1-2%) the contribution of 14 C from the reactors to the environment is so small that it is difficult to separate it from the prevailing background levels of 14 C . This is the case for all sampling procedures: in air and vegetation as well as in annual tree rings. Only on a few occasions an actual increase is observed. However, although the calculations suffer from rather large uncertainties, the calculated release rate from Barsebaeck is in fair agreement with reported release data. The results of this investigation show

  15. Synthesis of [21-14C]-fusarin C by enzymic demethylation and remethylation with [14C]-diazomethane

    International Nuclear Information System (INIS)

    Lu, S.-J.; Li, M.H.

    1989-01-01

    Fusarin C, a potent mutagen isolated from Fusarium moniliforme culture extracts, has been prepared radiolabeled in two steps by enzymic hydrolysis of the 21-methyl ester group, using phenobarbital induced microsomal preparations, followed by remethylation using [ 14 F]-diazomethane. Yields, based upon fusarin C, were essentially quantitative and approximately 10% of the [ 14 C]-methyl-nitrosourea, converted to diazomethane, reacted to yield [ 14 C]-fusarin C. (author)

  16. Characterization of 14C in Swedish light water reactors.

    Science.gov (United States)

    Magnusson, Asa; Aronsson, Per-Olof; Lundgren, Klas; Stenström, Kristina

    2008-08-01

    This paper presents the results of a 4-y investigation of 14C in different waste streams of both boiling water reactors (BWRs) and pressurized water reactors (PWRs). Due to the potential impact of 14C on human health, minimizing waste and releases from the nuclear power industry is of considerable interest. The experimental data and conclusions may be implemented to select appropriate waste management strategies and practices at reactor units and disposal facilities. Organic and inorganic 14C in spent ion exchange resins, process water systems, ejector off-gas and replaced steam generator tubes were analyzed using a recently developed extraction method. Separate analysis of the chemical species is of importance in order to model and predict the fate of 14C within process systems as well as in dose calculations for disposal facilities. By combining the results of this investigation with newly calculated production rates, mass balance assessments were made of the 14C originating from production in the coolant. Of the 14C formed in the coolant of BWRs, 0.6-0.8% was found to be accumulated in the ion exchange resins (core-specific production rate in the coolant of a 2,500 MWth BWR calculated to be 580 GBq GW(e)(-1) y(-1)). The corresponding value for PWRs was 6-10% (production rate in a 2,775 MWth PWR calculated to be 350 GBq GW(e)(-1) y(-1)). The 14C released with liquid discharges was found to be insignificant, constituting less than 0.5% of the production in the coolant. The stack releases, routinely measured at the power plants, were found to correspond to 60-155% of the calculated coolant production, with large variations between the BWR units.

  17. Detection of 14C in natural trace organics recovered from groundwater

    International Nuclear Information System (INIS)

    Murphy, E.; Long, A.; Davis, S.N.; Donahue, D.

    1985-01-01

    Radiocarbon measurements on dissolved inorganic carbon (DIC) in groundwater have given the authors insight into chemical and hydrological processes occurring in aquifers. Carbon-14 analyses on various dissolved organic carbon (DOC) fractions from groundwater are only starting, but, as is true for DIC 14 C measurements, their significance reaches beyond dating of water and into chemical processes in the aquifer and recharge zone. When combined with information on the chemical character of the DOC, 14 C data may clarify the origin and diagenesis of organic carbon in groundwater. In the past, research into the 14 C has been discouraged by the low concentrations of DOC in groundwater, typically in the μg/l range. The tandem accelerator at the University of Arizona can analyze 14 C in as little as 1 mg of carbon, thus requiring isolation of the DOC from 200 l or less of groundwater. This paper describes the techniques bring used for separation of the DOC in groundwater, some of the data collected, and the significance of these data

  18. Seasonal changes in within-canopy allocation of 14C-photosynthate by white oak

    International Nuclear Information System (INIS)

    McLaughlin, S.B.; McConathy, R.K.; Beste, B.

    1979-01-01

    Seasonal changes in photosynthate translocation and allocation of two mature, codominant white oak trees were studied by following rates of movement of 14 C-photosynthate from foliage labeled with 14 CO 2 . Loss rates were determined by sampling foliage at 5 min and 1, 4, and 7 days after labeling on each of five dates (April 22 to October 4). Incorporation of 14 C-photosynthate into 1-, 3-, and 5-year-old branches was determined 7 days after tagging. Losses of 14 C from leaves were rapid by day 1 (less than or equal to 80 percent), greatly reduced by day 4, and ranged fom 63 to 91 percent by day 7. Maximum retention of initial activity levels occurred in April for leaves (44 percent) and in October for branches (15 percent). Approximately equal apportionment of activity between leaves and branches did not occur until August. Highest total retention of photosynthate in the canopy occurred in April (due to high incorporation in leaves) and June (due to high retention in both leaves and branches). Based on measured retention and estimated respiration losses, translocation of the original 14 C-photosynthate from the canopy was calculated to be approximately 0 percent in April, 30 percent in June, and 60 percent in October. These results indicate that canopy growth and maintenance impose a significant drain on availability of photosynthate throughout the growing season

  19. Ambiguous hydraulic heads and 14C activities in transient regional flow.

    Science.gov (United States)

    Schwartz, Franklin W; Sudicky, Edward A; McLaren, Robert G; Park, Young-Jin; Huber, Matthew; Apted, Mick

    2010-01-01

    A regional flow and transport model is used to explore the implications of significant variability in Pleistocene and Holocene climates on hydraulic heads and (14)C activity. Simulations involve a 39 km slice of the Death Valley Flow System through Yucca Mountain toward the Amargosa Desert. The long-time scale over which infiltration has changed (tens-of-thousands of years) is matched by the large physical extent of the flow system (many tens-of-kilometers). Estimated paleo-infiltration rates were estimated using a juniper pollen percentage that extends from the last interglacial (LIG) period (approximately 120 kyrbp) to present. Flow and (14)C transport simulations show that groundwater flow changes markedly as a function of paleoclimate. At the last glacial maximum (LGM, 21 kyrbp), the recharge to the flow system was about an order-of-magnitude higher than present, and water table was more than 100 m higher. With large basin time constants, flow is complicated because hydraulic heads at a given location reflect conditions of the past, but at another location the flow may reflect present conditions. This complexity is also manifested by processes that depend on flow, for example (14)C transport. Without a model that accounts for the historical transients in recharge for at least the last 20,000 years, there is no simple way to deconvolve the (14)C dates to explain patterns of flow.

  20. No evidence for a deglacial intermediate water Δ14C anomaly in the SW Atlantic

    Science.gov (United States)

    Sortor, R. N.; Lund, D. C.

    2010-12-01

    Reconstructions of Δ14C from the eastern tropical Pacific show that severe depletions in 14C occurred at intermediate depths during the last deglaciation (Marchitto et al. 2007; Stott et al. 2009). Marchitto et al. (2007) suggested that old radiocarbon from an isolated abyssal reservoir was injected via the Southern Ocean, and that this anomaly was then carried by Antarctic Intermediate Water (AAIW) to the tropical Pacific. However, a core from the southeastern Pacific Ocean near Chile, which is in the direct path of modern-day AAIW, does not exhibit the excursion and therefore casts doubts upon the AAIW mechanism (De Pol-Holz et al. 2010). Here we evaluate whether or not a deglacial 14C anomaly similar to that in the eastern tropical Pacific occurred at intermediate depths in the South Atlantic. We reconstructed Δ14C using planktonic and benthic foraminifera from core KNR159-5-36GGC on the Brazil Margin (27○31’S and 46○28’W, 1268 m depth). In the modern ocean, the hydrography near this core site is heavily influenced by AAIW (Oppo & Horowitz, 2000). Benthic Δ14C values were determined using raw benthic 14C ages and calendar-calibrated planktonic ages. The deglacial benthic Δ14C trend at this site is similar to the atmospheric Δ14C trend, and is consistent with U/Th-dated corals from intermediate depths on the Brazil Margin (Mangini et al. 2010). The amplitude and timing of Δ14C changes in the foraminiferal and coral records are especially congruous during the Mystery Interval. We find no evidence in the southwestern Atlantic of a ~300‰ decrease in intermediate water Δ14C beginning at 18 kyr BP. Changes in reservoir age of ~1000 years are required to create a Baja-like Δ14C anomaly off Brazil, an implausible increase for a subtropical gyre location. Furthermore, the resulting sedimentation rates would be up to ~145 cm/kyr during the deglaciation, an order of magnitude higher than the average sedimentation rate for 36GGC. When our results are

  1. Radiocarbon dating

    International Nuclear Information System (INIS)

    Lazos R, L.

    2005-01-01

    The application of the radiocarbon dating in archaeology has not served only to solve problems related with the establishment of chronologies, but also in the development of archaeological methods of excavation and interpretation. This has been possible because the dating method by radiocarbon provides a common temporary scale that transcends the cultural and regional frontiers. It is even spoken of the revolution that has meant the fact that the application of this method has allowed to the archaeologist to pass from the construction of chronologies until the evaluation and dynamic interpretation of the archaeological data to build theories. This work explains and compares methods for the detection of 14 C, as the gas counting, the liquid scintillation counting and the mass spectrometry with accelerators. (Author)

  2. Analysis of Δ14C variations in atmosphere

    International Nuclear Information System (INIS)

    Simon, J.; Sivo, A.; Richtarikova, M.; Holy, K.; Polaskova, A.; Bulko, M.; Hola, O.

    2005-01-01

    The Δ 14 C in the atmosphere have been measured and studied in two localities of Slovakia. The accomplished analysis proved the existence of the annual variations of the Δ 14 C with the attenuating amplitude and decreasing mean value. It seems to be logical and physically correct to describe the Δ 14 C time-dependence by the equation: y = Ae -at + Be -bt cos(ω 1 t + (φ)). The coefficients A, a, B, b, (φ) are listed in the table for both the localities. The observed variations of the Δ 14 C have a maximum in summer and minimum in winter .Probably it is caused by the higher requirement of the heat supply in winter season which is connected directly with the fossil CO 2 emissions and more intensive Suess effect. Summer maximum could be explained by the combination of the lower CO 2 emission rate and higher turbulent transport of the stratospheric 14 C to the troposphere. Using the Fourier harmonic analysis the amplitude spectra of the average annual variations were plotted. The obtained result shows that the variations have the high degree of symmetry. Furthermore, the obtained basic frequency ω 1 = 2π/12 [month -1 ] proves that the cyclic processes with the period of T = 12 [month] have a major influence on the 14 C amount in the troposphere. The presence of some higher-order harmonics is significant, but a physical interpretation has not yet been clear. In addition to the main frequency there are presented also 2ω 1 and 3ω 1 in Bratislava and 4ω 1 in Zlkovce data-set. The long-time average of the Δ 14 C in Zlkovce during years 1995-2004 is higher of about 6.6 o / oo than in Bratislava. It represents an unique evidence that the local CO 2 pollution affects the 14 C activity . The correlation on the level R 2 = 0,43 was found between Bratislava and Zlkovce atmospheric Δ 14 C data. (authors)

  3. Monitoring of the 14C activity in the atmosphere

    International Nuclear Information System (INIS)

    Svingor, E.; Molnar, M.; Futo, I.; Rinyu, L.

    2006-01-01

    Complete text of publication follows. The distribution of atmospheric radiocarbon has been extensively investigated both in the Northern and Southern Hemisphere as well as in the Tropics for a number of decades. Systematic global observations of 14 CO 2 in the troposphere were made during and after atmospheric nuclear weapon tests in the 1950s and 1960s by several laboratories. Nowadays the monitoring of 14 C in regions adjacent to nuclear power plants (NPP) or sites of land-filled radioactive wastes has growing importance in determining the frequency and activity of anthropogenic 14 C released to the environment. On the other hand, the depletion of 14 C in the atmosphere gives information about the regional fossil fuel CO 2 contributions (Figure 1., Prague-Bulovka). The 14 C activity of the atmosphere has been monitored in the vicinity of Paks NPP by sampling environmental air monthly since 1994. Four differential sampling units collect air samples less than 2 km away from the 100- m-high stacks of Paks NPP (A-type stations), and for reference a sampler is operated at a station (B24) ca. 30 km away from Paks NPP. The highest 14 C values were measured at the site located less than 1km away from Paks NPP. The influence of the 14 C discharge in the environment decreases rapidly with the distance from the source and under normal operating conditions the effect of Paks NPP is negligible at a distance of 2.5km. In Figure 1. we have compared our data for Paks NPP measured during the time span of 2000 - 2005 with data from different European monitoring stations. (The 14 C activities are given in Δ values: Δ 14 C(% (A sample /A standard -1) x 1000.) In 2000-2001 the excess 14 C at Paks NPP compared to the B24 was 5-10 (per mille) but its Δ value didn't exceed the tropospheric background (1). With the growing traffic the inactive CO 2 emission (Suess effect) exceeded the influence of the NPP (2). After a cleaning tank incident at unit 2 of Paks NPP in April 2003 a 5

  4. Charged particle reaction studies on /sup 14/C. [Spectroscopic factors

    Energy Technology Data Exchange (ETDEWEB)

    Cecil, F E; Shepard, J R; Anderson, R E; Peterson, R J; Kaczkowski, P [Colorado Univ., Boulder (USA). Nuclear Physics Lab.

    1975-12-22

    The reactions /sup 14/C(p,d), (d,d') and (d,p) have been measured for E/sub p/ = 27 MeV and E/sub d/ = 17 MeV. The (d,d') and (d,p) reactions were studied between theta/sub lab/ = 15/sup 0/ and 85/sup 0/; the (p,d) reactions, between theta/sub lab/ = 5/sup 0/ and 40/sup 0/. The /sup 14/C deformation parameters were deduced from the deuteron inelastic scattering and found to agree with deformations measured in nearby doubly even nuclei. The spectroscopic factors deduced from the (p,d) reaction allowed a /sup 14/C ground-state wave function to be deduced which compares favorably with a theoretically deduced wave function. The (p,d) and (d,p) spectroscopic factors are consistent. The implications of our /sup 14/C ground-state wave function regarding the problem of the /sup 14/C hindered beta decay are discussed.

  5. C-14 dating and C-13/C-12 isotopic ratio in soils covered by natural vegetation of cerrado-floresta ecosystem at Humaita (AM)/Brazil

    International Nuclear Information System (INIS)

    Gouveia, Susy E.M.; Pessenda, Luiz C.R.; Roveratti, Renato; Cruz, Maria V.L.; Pessin, Glaucia; Aravena, Ramon; Boulet, Rene

    1996-01-01

    The most recent evidences show that in the Amazon region significant climatic changes occurred in the Quaternary, with emphasis to the dry periods during the Pleistocene and increased precipitation in the Holocene. In this region are found areas with characteristics of cerrado, surrounded by tropical rain forest. The evaluations of soil, vegetation and climate interactions for the formation of these areas are important. Carbon isotopes ( 12 C, 13 C, 14 C) have been applied in soil organic matter (SOM) of Humaita region, southern Amazon, to evaluate changes in vegetation communities during the Holocene. Isotopic composition of SOM in the deeper part of the soil profiles, shows that probably in the early Holocene the forest has been in the area today occupied by the cerrado vegetation. The results of SOM in the shallow part of soil profiles characterize perfectly the three types of actual vegetation communities. (author)

  6. Radionuclide dating ({sup 21}Pb, {sup 137}Cs, {sup 241}Am) of recent lake sediments in a highly active geodynamic setting (Lakes Puyehue and Icalma-Chilean Lake District)

    Energy Technology Data Exchange (ETDEWEB)

    Arnaud, F. [Processus et Bilan en Domaine Sedimentaire, UMR CNRS 8110, Bat. SN5, UST Lille 1, F-59655 Villeneuve d' Ascq (France); Geodynamique des Chaines Alpines, UMR CNRS 5025, Bat. Belledonne, Universite de Savoie, F-73373 Le Bourget du Lac (France); Magand, O. [Laboratoire de Glaciologie et Geophysique de l' Environnement, UMR CNRS 5183, 54 rue Moliere, F-38402 Saint Martin d' Heres Cedex (France)]. E-mail: magand@lgge.obs.ujf-grenoble.fr; Chapron, E. [Renard Centre of Marine Geology, University of Gent, Department of Geology and Soil Science, Krijgslaan 281 S8, B-9000 Gent (Belgium); Bertrand, S. [U.R. Argiles et Paleoclimats, University of Liege, Allee du 6 Aout, B18, ULG-Sart-Tilman, B-4000 Liege (Belgium); Boes, X. [U.R. Argiles et Paleoclimats, University of Liege, Allee du 6 Aout, B18, ULG-Sart-Tilman, B-4000 Liege (Belgium); Charlet, F. [Renard Centre of Marine Geology, University of Gent, Department of Geology and Soil Science, Krijgslaan 281 S8, B-9000 Gent (Belgium); Melieres, M.-A. [Laboratoire de Glaciologie et Geophysique de l' Environnement, UMR CNRS 5183, 54 rue Moliere, F-38402 Saint Martin d' Heres Cedex (France)

    2006-08-01

    This study presents an attempt to use radionuclide profiles to date four short sediment cores taken from two Chilean lakes located in a highly active geodynamic setting. In such settings, sediment series commonly contain earthquake-triggered reworked layers and/or volcanic ash layers. All of these layers affect the vertical distribution of radionuclides. The drawing up of accurate chronologies is made even more problematic by the low fallout rates of both natural ({sup 21}Pb) and artificial ({sup 137}Cs, {sup 241}Am) radionuclides. However, radionuclide profiles can be 'corrected' by subtracting the influence of instantaneous deposits that have been identified from detailed sedimentological studies. Thus, radionuclides can be used to provide approximate dates for sediment. Independent confirmation of these dates can be provided by varve counting and/or the recognition of historical events. For Lake Puyehue, this approach has allowed particular sediment features to be related to the effects of the 1960 Chilean earthquake (Mw 9.5) on the lake basin and its catchment area. For Lake Icalma, there is a good agreement between radionuclide dates and the dates of the three tephra layers formed during large eruptions of the Llaima volcano in 1946, 1917 and 1883. For both lakes, artificial radionuclide fallout, which culminated in 1965, provides more robust chronological information than {sup 21}Pb dating.

  7. AMS measurement of C-14 concentration in a single-year ring of a 2500-yr-old tree

    International Nuclear Information System (INIS)

    Sakurai, H.; Gandou, T.; Kato, W.; Sawaki, Y.; Matsumoto, T.; Aoki, T.; Matsuzaki, H.; Gunji, S.; Tokanai, F.

    2004-01-01

    The 14 C concentration in rings of an old tree that date back approximately 2500 yr has been measured at single-year intervals with a highly accurate liquid scintillation counter (LSC) (0.2%) to investigate the 11-yr periodicity of solar activity. To investigate the applicability of AMS to accurate 14 C measurement, 16 graphite samples produced from the cellulose of a single-year tree ring of a 2500-yr-old cedar were measured with the micro analysis laboratory tandem (MALT) accelerator, at The University of Tokyo, and the results were compared with the 14 C age determined using LSC. The average 14 C age of the single-year tree ring calculated from 16 measurements was 2496 ± 23 yr BP, corresponding to the statistical accuracy of 0.26%. This was consistent with the age of 2514 ± 23 yr BP determined using LSC within the acceptable error range, which indicates that accelerator mass spectrometry (AMS) is applicable for accurate 14 C measurement using multi-graphite for the same single-year tree ring

  8. Persistence of 14C maneb in lettuce plants an soil

    International Nuclear Information System (INIS)

    Bennaceur, M.; Sennaoui, Z.; Meguenni, H.

    1992-10-01

    Maneb residue is studied on lettuce plant and soil after spraying on greenhouse with 14C maneb. The residues declined with time. After 37 days from the application, 14C maneb residues in water extracts declined to 1,5. 10-2ug/g from 5,8. 10-1ug/g of the zero day sample in lettuce plants and 4,6. 10-3ug/g from 1,73. 10-1ug/g in soil. The 14C internals residues in lettuce and soil increase respectively till 16 days and 24 days, then decrease to 88% and 4,05% after 37 days. ETU was present in lettuce plant after 8 days then decreases with time. Two metabolites were identified by TLC (EU,ETU)

  9. Temporal distribution of bomb 14C in a forest soil

    International Nuclear Information System (INIS)

    Harkness, D.D.; Harrison, A.F.; Bacon, P.J.

    1986-01-01

    Patterns of 14 C enrichment in the superficial plant debris and mineral soil horizons of an established woodland have been monitored at regular intervals during the past 15 years. These data are compared with a model evaluation of carbon turnover based on the recorded changes in atmospheric 14 C concentration since AD 1900. Leaf litter and decomposing plant debris are characterized by steady-state turnover values of ca 2 and ca 8 years, respectively. A two-component system of fast (≤20 yr) and slow (ca 350 yr) cycling carbon is indicated for the surface (0-5cm) soil humus; below 10cm, the fast component is rare ( 14 C to the soil carbon pool

  10. Effect of tolbutamide on 14C-sodium bicarbonate and 14C-alanine metabolism in isolated rat hepatocytes

    International Nuclear Information System (INIS)

    Kunjathoor, V.V.; Ye, Y.; Pillai, U.A.; Ferguson, P.W.; Medon, P.J.

    1990-01-01

    Tolbutamide (TOLB) is a sulfonylurea commonly used in the treatment of noninsulin-dependent diabetes mellitus. Studies have shown that TOLB affects gluconeogenesis and glycolysis from various substrates in the liver. Specifically, TOLB inhibits gluconeogenesis from lactate in a dose-dependent manner. In order to further clarify tolbutamide's mechanism of action, its effect on the incorporation of 14 C from NaH 14 CO 3 and 14 C-alanine into glucose, lactate or pyruvate in the presence of lactate was measured. Rat hepatocytes were incubated with lactate (2.0 mM) with or without TOLB (1.0 mM) in the presence of NaH 14 CO 3 or 14 C-alanine. TOLB inhibited the incorporation of C 14 from NaHCO 3 and alanine into glucose by 55 and 56%, respectively. TOLB did not alter the incorporation of C 14 from NaHCO 3 into lactate or pyruvate. TOLB did not affect the incorporation of 14 C from alanine into lactate but produced a pooling of 14 C as pyruvate. The authors data support studies demonstrating the TOLB produces its actions, in part, by increasing the concentration of fructose-2,6-bisphosphate and inhibiting pyruvate carboxylase

  11. Anthropogenic 14C in the natural (aquatic) environment

    International Nuclear Information System (INIS)

    Begg, F.H.

    1992-11-01

    Increasing global awareness of the radiological significance of 14 C releases from the nuclear and radiochemical industries has resulted in a number of studies within the last decade investigating the atmospheric releases and their effect on the terrestrial biosphere. The basis of this study was to determine the behaviour and environmental distribution of anthropogenically produced 14 C released to the aquatic environment from the nuclear fuel reprocessing plant at Sellafield. Most sampling was undertaken in the Irish Sea with smaller scale studies being carried out in the Bristol Channel and the Grand Union Canal. Within the study area, from Earnse Point 40 km south of Sellafield, northwards to the Clyde Sea area, preliminary studies on intertidal biota samples ie. mussels, winkles and seaweed indicated enriched 14 C specific activities in all the samples relative to the current ambient level of 115.4 pM. The highest activities were observed in the immediate vicinity of the discharge location; mussels with a measured activity of 787 pM, winkles of 613 pM and seaweed of 415 pM. The 14 C specific activity observed at most sites appeared to be organism dependent with mussels>winkles>seaweed. This is the result of differences in the uptake mechanisms of the organisms and indicates that the dissolved inorganic carbon and the particulate material within the water column are enriched in 14 C . However, on analysis of the biogeochemical fractions of the water column, enriched 14 C activities were observed only in the DIC fraction which could explain those activities found in the seaweed but not those in the mussels and winkles. Enriched 14 C activities were found in the phytoplankton, indicating that there is a source of enriched organic particulate material within the water column as a result of photosynthetic uptake of enriched DIC, however this will be a seasonal effect. Nevertheless, this enrichment is still not high enough to support the activities observed in the

  12. Synthesis of 14C labelled lidocaine (α-diethylamino acet-2,6-dimethylanilide)

    International Nuclear Information System (INIS)

    Zhou Zhentang; Qian Guojun; Lin Fenzhi; Zhuang Daoling; Zhang Yulong; He Zhanjun

    2002-01-01

    14 C-lidocaine was composed by 14 C-diethylamine reaction with ω-chloroacetic-2,6-dimethylaniline. 14 C-diethylamine was prepared from Ba 14 CO 3 via K 14 CN and 14 C-acetonitrile which was hydrogenated. Radiochemical purity of 14 C-diethylamine and 14 C-lidocaine is >99% by HPLC and TLC respectively. 14 C-lidocaine is needed for breath assay of mouse for measuring liver function

  13. One Isotope, Two Tales: using plant and cosmogenic 14C to constrain Holocene glacier activity on Baffin Island.

    Science.gov (United States)

    Pendleton, S.; Miller, G. H.; Lifton, N. A.; Young, N. E.

    2017-12-01

    As the cryosphere continues to undergo rapid and accelerating change, it is more important than ever to understand past glacier activity to predict the future of the cryosphere. However, continuous Holocene glacier records are notoriously difficult to reconstruct because an advancing glacier will re-incorporate previous deposits so that moraines typically only record the farthest downvalley glacier expansion. Here we combine dates of ice margin advance from in situ dead vegetation with in situ cosmogenic 14C (in situ 14C) from preserved bedrock surfaces at the same locations to further constrain the timing of ice-free episodes during the Holocene following deglaciation on southern Baffin Island. Radiocarbon ages from recently exposed in situ plants suggest that ice last advanced over sample locations at 9.4, 9.2, 9.0, and 3.7 ka and that they remained ice covered until modern times. Associated in situ 14C inventories are variable, but well above background levels, suggesting some amount of Holocene in situ 14C production. Using plant 14C ages representing the beginning of ice coverage and in situ 14C inventories representative of exposure prior to ice coverage, a simple model of cosmogenic in situ 14C production (accounting for muon production through ice) provides constraints timing and duration of ice-free times at sample locations prior to their most recent burial. Using conservative Holocene ice thicknesses, the locations buried at 9.4, 9.2, and 9.0 ka require, at minimum, 1000 years of pre-burial exposure to match the observed in situ 14C inventory. This suggests these locations were ice free by at least 10 ka and likely earlier. The in situ 14C inventory at the location buried at 3.7 ka limits prior exposure to 2000 years, suggesting that this location experienced more complex Holocene ice cover/burial history. These pilot data show that valuable information regarding periods of exposure is contained within in situ 14C inventories. Additional paired plant and

  14. Direct preparation of 14C-labelled 5-allyl- and 5-propyl-2'-deoxyuridine from [2-14C]2'-deoxyuridine

    International Nuclear Information System (INIS)

    Ruth, J.L.; White, S.K.; Bergstrom, D.E.

    1982-01-01

    [2- 14 C]5-Allyl-2'-deoxyuridine was synthesized directly from [2- 14 C]2'-deoxyuridine using mercury, palladium, and 3-chloropropene. [2- 14 C]5-Propyl-2'-deoxyuridine was obtained by hydrogenation of the [ 14 C]5-allyl-2'-deoxyuridine. Advantages of the synthetic method and its application to the preparation of other radiolabeled 5-alkyl/alkenyl-2'-deoxyuridines are discussed. (author)

  15. Mineralization of 14C-labeled agrochemicals in soil

    International Nuclear Information System (INIS)

    Xu Bujin; Huang Xiaohua; Hu Xiuqing; Zhang Yongxi

    2001-01-01

    14 C-labeled compounds were used to study the mineralization of methamidophos, 2,4-D and metsulfuron in soil. Mineralization rate was influenced by the type of soil, concentration of chemical in the soil, the initial soil microbial population and the nature of the chemical. (author)

  16. Method of preparing (U-14C)-D-galactose

    International Nuclear Information System (INIS)

    Zemek, J.; Kucar, S.; Kolina, J.

    1982-01-01

    Whole Chlorella algae cells cultivated in a 14 CO 2 medium were subjected to a β-galactosidase solution buffered to pH=4.5 to 6.0. The produced (U- 14 C)-D-galactose is separated by paper chromatography. (E.S.)

  17. Process for the production of 14C-labelled compounds

    International Nuclear Information System (INIS)

    Oldham, K.G.; Carr, N.G.

    1978-01-01

    The patent describes the production of 14 C-labelled compounds from solution with the aid of algae. A microorganism of the Anacystic species is used, preferably Anacystis nidulans which is also known as 'Indiana 625'. The experiments and their results are described in detail. (UWI) [de

  18. Acceleration of 14C beams in electrostatic accelerators

    International Nuclear Information System (INIS)

    Rowton, L.J.; Tesmer, J.R.

    1981-01-01

    Operational problems in the production and acceleration of 14 C beams for nuclear structure research in Los Alamos National Laboratory's Van de Graaff accelerators are discussed. Methods for the control of contamination in ion sources, accelerators and personnel are described. Sputter source target fabrication techniques and the relative beam production efficiencies of various types of bound particulate carbon sputter source targets are presented

  19. Plasma kinetics of 14C-uric acid in bulls

    International Nuclear Information System (INIS)

    Cetinkaya, N.

    1999-01-01

    Plasma kinetics of uric acid were followed by 14C labelled uric acid to measure the effects of feed intake upon kinetic parameters. Two bulls (average L W 346±79 kg) were given an intravenous administration of a tracer (8-14C-uric acid, 250μCi/50 ml) by single injection via a jugular catheter. Animals were fed a mixed diet containing 30% wheat straw and 70% compounded feed as 95 and 60 % of the voluntary intake. Voluntary intakes were 8 kg/d as fed for two bulls. Blood samples, were collected at 0, 0.5,1, 2, 3, 4, 6, 8, 12, 16, 24 and 28 h after tracer administration. Fractional rates of clearance from the blood and pool size of compartments in the blood were estimated using plasma 8-14C-counts, following the method proposed by Chen and Franklin. The mean values of fractional rates (K 2,1 , K 1,2 ) and compartments pool size (V 1 , V 2 ) and the total pool size of compartments I and 2 at 60% and 95% feeding level were 1.97 and 1.44, 1.06 and 0.78; 76.9 L and 94.5 L, 137.01 L and 163.51 L; 214.0 L and 250.3 L respectively. Plasma kinetic parameters of 14C-uric acid were not affected at different feed intakes

  20. Photosynthetic incorporation of 14C by Stevia rebaudiana

    International Nuclear Information System (INIS)

    Ferraresi, M. de L.; Ferraresi Filho, O.; Bracht, A.

    1985-01-01

    The photosynthetic incorporation of 14 by Stevia rebaudiana specimens was investigated. The 14 C incorporation, when the isotope was furnished to the plant in form of 14 CO 2 , was rapid. After 24 hours, the radioactivity has been incorporated into a great number of compounds including pigments, terpenes, glucose, cellulose and also stevioside and its derivatives. (M.A.C.) [pt

  1. Modified synthesis of 11-[{sup 14}C]-clozapine

    Energy Technology Data Exchange (ETDEWEB)

    Matloubi, Hojatollah E-mail: hmatloubi@seai.neda.net.ir; Ghandi, Mehdi; Zarrindast, M.-R.; Saemian, Nader

    2001-11-01

    The reported synthetic pathway of 8-chloro-11-(4-methyl-1-piperazinyl)-11-[{sup 14}C]-5H-dibenzo[b,e][1,4]diazapine (clozapine) was modified in several steps. The synthetic pathway was shortened by 60% and the total yield was increased from 6% to 23%.

  2. Modified synthesis of 11-[14C]-clozapine

    International Nuclear Information System (INIS)

    Matloubi, Hojatollah; Ghandi, Mehdi; Zarrindast, M.-R.; Saemian, Nader

    2001-01-01

    The reported synthetic pathway of 8-chloro-11-(4-methyl-1-piperazinyl)-11-[ 14 C]-5H-dibenzo[b,e][1,4]diazapine (clozapine) was modified in several steps. The synthetic pathway was shortened by 60% and the total yield was increased from 6% to 23%

  3. Biokinetic studies on 14C-chitosan in rats

    International Nuclear Information System (INIS)

    Jia Minghong; Nishimura, Y.; Watanabe, Y.; Yukawa, M.

    1998-05-01

    The absorption and the basic metabolism of chitosan in rats are investigated. The results indicated that 14 C-chitosan from gastrointestinal tract was absorbed, metabolized and excreted quickly without re-bioavailability. The radioactive compounds perhaps with specifically chemical forms in serum, liver and the contents of small intestines were separated on GPC column and measured by radioactivity counting. A big pile of peaks with the retention volume almost same as that of standard 14 C-chitosan and another sharp one with the retention volume in the range of higher molecular weight same as that of BSA were discovered in analysis respectively for contents of intestine and serum or liver. The sharp peak would disappear if the proteins contained in the serum or liver were removed. In addition, and interesting tail peak, followed with the pile ones and eluted with the retention volume of lower molecular weight range same as that of chitooligosaccharides was also found in each of the 3 samples, ignoring the protein removal or not. These results suggested that most of 14 C-chitosan was not to be digested in intestine. On the other hand, a small amount of 14 C-chitosan was likely to be absorbed directly or after degraded to small molecular compounds into blood, liver and other tissues, and then connected with the proteins. Perhaps it is these trace materials that were playing important roles in reduction of the bioavailability of radiostrontium in rats

  4. The synthesis of [14C] C I pigment violet 19

    International Nuclear Information System (INIS)

    Filer, C.N.; Kelly, T.P.

    1990-01-01

    For the custom synthesis of radiolabeled compounds in the authors laboratory, aside from spectroscopic examination, their identity and radiochemical purity is routinely corroborated by demonstration of cochromatography with an authentic cold standard. In the synthesis of [ 14 C] red pigment 1 for the Cosmetic Toiletry and Fragrance Association, its insolubility precluded this. The preparation as well as characterization of 1 is described

  5. Synthesis of glycerides and glycerophospholipides labelled with 14C

    International Nuclear Information System (INIS)

    Danan, J.-L.

    1977-01-01

    Glycerides and glycerophospholipides labelled with 14 C were chemically synthetized using isopropylidene-D-glycerol prepared from D mannitol. The acylation method by labelled fatty acid chlorides was utilized. An original synthesis method was developed for the phospholipides using cyclic enediol pyrophosphate [fr

  6. Residues of 14C-cyolane in cottonseed products

    International Nuclear Information System (INIS)

    Zayed, S.M.A.D.; Osman, A.Z.; Fakhr, I.M.I.; Bahig, M.E.

    1981-01-01

    The systemic insecticide cyolane [2-(0,0-diethylphosphoryl)-imino-1,3-dithiolane] was prepared from 14 C-ethanol, phosphorus oxychloride and 2-amino-1,3-dithiolane. Cotton plants were treated with two applications of the insecticide under conditions of local agricultural practice. 14 C-residues in the crude oil and cake of the harvested cotton seeds amounted to 1.63 and 0.014 mg/kg respectively. About 50% of the 14 C-activity present in the crude oil was found to be eliminated by simulated commercial processes used for refining of the oil. Alkali treatment and bleaching removed 16% and 25% of the radioactive residues respectively. Winterization of the bleached oil at 5-7 0 C for 3 days effected a further elimination of 13%. 14 C-residues in the cotton seed products and in the samples of the refined oil were characterized and the main constituents identified using chromatographic techniques. (author)

  7. Extraction of in situ cosmogenic 14C from olivine

    Science.gov (United States)

    Pigati, J.S.; Lifton, N.A.; Timothy, Jull A.J.; Quade, Jay

    2010-01-01

    Chemical pretreatment and extraction techniques have been developed previously to extract in situ cosmogenic radiocarbon (in situ 14C) from quartz and carbonate. These minerals can be found in most environments on Earth, but are usually absent from mafic terrains. To fill this gap, we conducted numerous experiments aimed at extracting in situ 14C from olivine ((Fe,Mg)2SiO4). We were able to extract a stable and reproducible in situ 14C component from olivine using stepped heating and a lithium metaborate (LiBO2) flux, following treatment with dilute HNO3 over a variety of experimental conditions. However, measured concentrations for samples from the Tabernacle Hill basalt flow (17.3 ?? 0.3 ka4) in central Utah and the McCarty's basalt flow (3.0 ?? 0.2 ka) in western New Mexico were significantly lower than expected based on exposure of olivine in our samples to cosmic rays at each site. The source of the discrepancy is not clear. We speculate that in situ 14C atoms may not have been released from Mg-rich crystal lattices (the olivine composition at both sites was ~Fo65Fa35). Alternatively, a portion of the 14C atoms released from the olivine grains may have become trapped in synthetic spinel-like minerals that were created in the olivine-flux mixture during the extraction process, or were simply retained in the mixture itself. Regardless, the magnitude of the discrepancy appears to be inversely proportional to the Fe/(Fe+Mg) ratio of the olivine separates. If we apply a simple correction factor based on the chemical composition of the separates, then corrected in situ 14C concentrations are similar to theoretical values at both sites. At this time, we do not know if this agreement is fortuitous or real. Future research should include measurement of in situ 14C concentrations in olivine from known-age basalt flows with different chemical compositions (i.e. more Fe-rich) to determine if this correction is robust for all olivine-bearing rocks. ?? 2010 by the Arizona

  8. C-14 bomb peak dating of human DNA samples at the microgram level

    International Nuclear Information System (INIS)

    Liebl, J. C.

    2011-01-01

    Radiocarbon (14C, t 1/2 = 5700 ± 30 years) is probably the radionuclide with the most versatile applications, spanning from archaeology to geoscience and medicine. Many of these applications are finally limited by the minimum amount of carbon in which the isotopic ratio 14C/12C can be measured. The required carbon sample size has dramatically decreased with the development of Accelerator Mass Spectrometry (AMS), typically from gram amounts for the classical beta counting method to about 1 milligram for AMS. The current work presents a further reduction into the few-μg carbon range. This means a decrease by a factor of one million compared to classical beta counting and is essential for the field of retrospective birth dating of human cells by means of radiocarbon from above-ground nuclear weapons testing between 1955 and 1963. The determination of 14C levels in genomic DNA can be used to retrospectively establish the birth date of cells in the human body. The main motive of the current work was to reduce the amount of carbon required for reliable 14C measurements to such an extent that investigations of neurons of particularly interesting small sections of the human brain (e.g. the olfactory bulb, bulbus olfactorius) were possible. In-depth investigations and development of 14C AMS sample preparation and measurement methods for μg-size DNA samples were carried out in close collaboration with the Department of Cell and Molecular Biology of the Karolinska Institute in Stockholm. As the most significant result, 14C measurements of 4.6 μg carbon DNA samples were performed with an overall precision of 2.3%. This allowed to study neurogenesis in the human olfactory bulb, which turned out to take place primarily at birth. Assuming throughout life a constant annual renewal rate of neurons in the human olfactory bulb, an upper limit of 0.34% for the renewal rate (95% confidence) was determined. At the Vienna Environmental Research Accelerator (VERA) the μg carbon

  9. Overcoming bioanalytical challenges in an Onglyza(®) intravenous [(14)C]microdose absolute bioavailability study with accelerator MS.

    Science.gov (United States)

    Xu, Xiaohui Sophia; Dueker, Stephen R; Christopher, Lisa J; Lohstroh, Pete N; Keung, Chi Fung Anther; Cao, Kai Kevin; Bonacorsi, Samuel J; Cojocaru, Laura; Shen, Jim X; Humphreys, W Griffith; Stouffer, Bruce; Arnold, Mark E

    2012-08-01

    An absolute bioavailability study that utilized an intravenous [(14)C]microdose was conducted for saxagliptin (Onglyza(®)), a marketed drug product for the treatment of Type 2 diabetes mellitus. Concentrations of [(14)C]saxagliptin were determined by accelerator MS (AMS) after protein precipitation, chromatographic separation by UPLC and analyte fraction collection. A series of investigative experiments were conducted to maximize the release of the drug from high-affinity receptors and nonspecific adsorption, and to determine a suitable quantitation range. A technique-appropriate validation demonstrated the accuracy, precision, specificity, stability and recovery of the AMS methodology across the concentration range of 0.025 to 15.0 dpm/ml (disintegration per minute per milliliter), the equivalent of 1.91-1144 pg/ml. Based on the study sample analysis, the mean absolute bioavailability of saxagliptin was 50% in the eight subjects with a CV of 6.6%. Incurred sample reanalysis data fell well within acceptable limits. This study demonstrated that the optimized sample pretreatment and chromatographic separation procedures were critical for the successful implementation of an UPLC plus AMS method for [(14)C]saxagliptin. The use of multiple-point standards are useful, particularly during method development and validation, to evaluate and correct for concentration-dependent recovery, if observed, and to monitor and control process loss and operational variations.

  10. Synthesis of [methyl-{sup 14}C]crotonobetaine from DL-[methyl-{sup 14}C]carnitine

    Energy Technology Data Exchange (ETDEWEB)

    Loester, H.; Seim, H. [Leipzig Univ. (Germany). Inst. of Clinical Chemistry and Pathobiochemistry

    1996-02-01

    The causes of carnitine deficiency syndromes are not completely understood, but decomposition of L-carnitine in vivo is likely to be involved. Carnitine is metabolized to {gamma}-butyrobetaine, and crotonobetaine is probably an intermediate in this pathway. To validate experimentally the precursor-product relationship between the three physiologically occuring {gamma}-betaines - L-carnitine, crotonobetaine, {gamma}-butyrobetaine - labelling with stable or radioactive isotopes became necessary. Methyl-labelled carnitine isomers (L(-)-, D(+)- or DL-) or {gamma}-butyrobetaine can be easily synthesized by methylation of 4-amino-3-hydroxybutyric acid isomers or 4-aminobutyric acid, respectively. Because of problems with the 4-aminocrotonic acid, we synthesized labelled crotonbetaine from labelled carnitine. Thus, DL-[methyl-{sup 14}C]carnitine was dehydrated by reaction with concentrated sulfuric acid. After removal of the latter the products were separated and purified by ion exchange chromatography on DOWEX 50 WX8 (200 - 400 mesh) and gradient elution with hydrochloric acid. In addition to the labelled main product [methyl-{sup 14}C]crotonobetaine (yield about 50 %), [methyl-{sup 14}C]glycine betaine and [methyl-{sup 14}C]acetonyl-trimethylammonium (ATMA) were formed. The end products were identified by combined thin layer chromatography/autoradiography and quantified by liquid scintillation counting. (Author).

  11. AMS radiocarbon dating at Oxford and its contribution to issues of the extinction of Neanderthals and the spread of Homo sapiens sapiens across Eurasia

    CERN Document Server

    Pettitt, P B; Hedges, R E M; Hodgins, G W L

    2000-01-01

    The Oxford Radiocarbon Accelerator Unit has participated in a number of projects central to the question of the evolutionary fate of the Neanderthals and the spread of our own species across Eurasia. This paper outlines some of the key issues in this field and reports on some dating projects which have refined our knowledge of these momentous events in human history.

  12. AMS radiocarbon dating at Oxford and its contribution to issues of the extinction of Neanderthals and the spread of Homo sapiens sapiens across Eurasia

    International Nuclear Information System (INIS)

    Pettitt, P.B.; Bronk Ramsey, C.; Hedges, R.E.M.; Hodgins, G.W.L.

    2000-01-01

    The Oxford Radiocarbon Accelerator Unit has participated in a number of projects central to the question of the evolutionary fate of the Neanderthals and the spread of our own species across Eurasia. This paper outlines some of the key issues in this field and reports on some dating projects which have refined our knowledge of these momentous events in human history

  13. Ignimbrite Analyses of Batur Caldera, Bali, based on 14C Dating

    Directory of Open Access Journals (Sweden)

    Igan S. Sutawidjaja

    2014-06-01

    Full Text Available http://dx.doi.org/10.17014/ijog.vol4no3.20094The Batur Caldera, in the northeastern part of Bali Island, is an elliptical collapse structure 13.8 by 10 km in size and another circular composite collapse structure with a diameter of 7.5 km in its centre. Two stages of the collapse were interrupted by silicic andesite lavas and domes. The first collapse was initiated by the eruption of about 84 km3 of the dacitic "Ubud Ignimbrite", about 29,300 years B.P., which caused a steep-walled depression about 1 km deep. The second ignimbrite was erupted from a large crater about the present lake, and it  produced about 19 km3 of a similar voluminous dacitic ignimbrite, called the "Gunungkawi Ignimbrite" about 20,150 years B.P. This second eruption trig- gered a second collapse, which created the central circular caldera, and formed a basin structure. Both the Ubud and Gunungkawi Ignimbrites consist of a similar dacitic composition, white to red (the most abundant nearly 90 % and dark grey to black dacitic pumice clasts. The large clasts, up to 20 cm in diameter, are in the non-welded ignimbrite, particularly in the upper part of the Gunungkawi Ignimbrite. The intracaldera ignimbrite, called the "Batur Ignimbrite" about 5 km3  in volume is a densely welded ignimbrite and generally shows typical welded features. The ignimbrite comprises at least five different flow units, separated by thin (15 - 40 cm welded pumiceous airfall deposits, with flattened pumice clasts. Another large eruption occurred about 5,500 years B.P., producing around 0.09 km3  andesitic ignimbrite. This was initiated by phreatomagmatic eruptions, indicated by thick phreatomagmatic and surge deposits, underlying the ignimbrite. The caldera and its vicinity are partly filled, and variably mantled by later eruptive products of dacitic and andesitic phreatomagmatic and airfall deposits.  

  14. The production of (14C) oxalate during the metabolism of (14C) carbohydrates in isolated rat hepatocytes.

    Science.gov (United States)

    Rofe, A M; James, H M; Bais, R; Edwards, J B; Conyers, R A

    1980-04-01

    Oxalate (14C) was produced during the metabolism of (U-14C) carbohydrates in hepatocytes isolated from normal rats. At 10 mM, the order of oxalate production was fructose > glycerol > xylitol > sorbitol greater than or equal to glucose in the ratio 10 : 4 : 3 : 1 : 1. This difference between oxalate production from fructose and glucose was reflected in their rates of utilisation, glucose being poorly metabolised in hepatocytes from fasted rats. Fructose was rapidly metabolised, producing glucose, lactate and pyruvate as the major metabolites. Glycerol, xylitol and sorbitol were metabolised at half the rate of fructose, the major metabolites being glucose, lactate and glycerophosphate. The marked similarity in the pattern of intermediary metabolites produced by these polyols was not, however, reflected in the rates of oxalate production. Hepatic polyol metabolism resulted in high levels of cytosolic NADH, as indicated by elevated lactate : pyruvate and glycerophosphate : dihydroxyacetone phosphate ratios. The artificial electron acceptor, phenazine methosulphate (PMS) stimulated oxalate production from the polyols, particularly xylitol. In the presence of PMS, the order of oxalate production was fructose greater than or equal to xylitol > glycerol > sorbitol in the ratio 10 : 10 : 6 : 2. The production of glucose, lactate and pyruvate from the polyols was also stimulated by PMS, whereas the general metabolism of fructose, including oxalate production, was little affected. Oxalate (14C) was produced from (1-14C), (2-14C) and (6-14C) but not (3,4-14C) glucose in hepatocytes isolated from non-fasted, pyridoxine-deficient rats. Whilst this labelling pattern is consistent with oxalate being produced by a number of pathways, it is suggested that metabolism via hydroxypyruvate is a major route for oxalate production from various carbohydrates, with perhaps the exception of xylitol, which appears to have an alternative mechanism for oxalate production. The observation that

  15. Applications, development, and control of methods for the determination of 14C

    International Nuclear Information System (INIS)

    Svetlik, Ivo; Tomaskova, Lenka; Dreslerova, Dagmar; Michalek, Vaclav

    2010-01-01

    The methods of determination of 14 C are outlined, and a comparison between the conventional methods and the processing of microsamples with measurement by accelerator mass spectrometry is presented. The assets of the processing of microsamples are highlighted and some applications are described. The development potential of the conventional method which is based on the synthesis of benzene and measurement by LSC at our laboratory is discussed. Currently, our radiocarbon laboratory performs experiments aimed at the processing of microsamples and preparation of graphitized targets. As to the control of the analytical methods, radiocarbon dating using existing dated material for repeated analyses and comparison of dating results with those obtained by other laboratories is a convenient approach

  16. Reactions of saccharides catalyzed by molybdate ions. XXXIII. Use of. cap alpha. (U-/sup 14/C)glucan for preparation of /sup 14/C-labelled saccharides

    Energy Technology Data Exchange (ETDEWEB)

    Bilik, V; Biely, P [Institute of Chemistry, Centre for Chemical Research, Slovak Academy of Sciences, Bratislava (Czechoslovakia); Kolina, J [Ustav pro Vyzkum, Vyrobu a Vyuziti Radioisotopu, Prague (Czechoslovakia)

    1984-01-01

    D-(U-/sup 14/C)glucose obtained in acid hydrolysis of ..cap alpha..-(U-/sup 14/C)glucan (2 M-HCl) was epimerized under a catalytic action of molybdate ions to D-(U-/sup 14/C)mannose isolated with a 20% yield. Oxidative degradation of 4-nitrophenylhydrazones of D-(U-/sup 14/C)arabinose and D-(U-/sup 14/C)xylose resulted in D-(U-/sup 14/C)erythrose and D-(U-/sup 14/C)threose, respectively, with a 15% yield relative to the starting aldopentoses. Nitromethane synthesis with D-(U-/sup 14/C)lyxose followed by oxidative decomposition of the corresponding nitrohexitols yielded /sup 14/C-labelled D-galactose. Described is also the preparation of D-(U-/sup 14/C)arabinose from D-(U-/sup 14/C)glucose and the conversion of D-(U-/sup 14/C)arabinose to D-(U-/sup 14/C)xylose and D-(U-/sup 14/C)lyxose.

  17. A critical review of atmospheric 14 C activities

    International Nuclear Information System (INIS)

    Krajcar Bronic, I.; Horvatincic, N.; Baresic, J.; Obelic, B.; Vreca, P.

    2006-01-01

    14 C activity of atmospheric CO 2 has been measured at the Rudjer Boskovi Institute as a part of environmental monitoring in order to determine possible differences between clean-air sites, industrialized city and sites in the vicinity of nuclear power plant. Samples of CO 2 from the atmosphere have been collected by absorption of CO 2 on the saturated carbonate-free NaOH solution for a period of 1 month under stationary conditions. The obtained Na 2 CO 3 has been dissolved in HCl and the produced CO 2 used for CH 4 preparation by catalytic reaction with H 2 at 450 degrees Celsius. A gas proportional counter filled with CH 4 has been used for 14 C activity measurement. The method of collection of CO 2 does not require any power source and can be therefore used for sampling at the remote sites, such as mountains or forests. However,due to the lack of mixing of the Na OH solution, the absorption process is limited on the surface of the solution, and there exists the possibility of fractionation of carbon isotopes due to different reaction rate constants of 12 C and 13 C. A continuous record of atmospheric 14 CO 2 activity exists for the city of Zagreb (1986 to 2005), while shorter records (1-2 years) exist for several other sites of various characteristics: two clean-air sites (Mt. Medvednica, altitude about 1000 m a.s.l., for period 1995 to 1996, and the Plitvice National Park for period 2003 to 2005), and a site close to the Nuclear Power Plant Krsko (1984 to 1986).Within the bilateral Croatian-Slovene project we have recently measured also the stable isotope composition (δ13 C) of Na 2 CO 3 collected at two different sampling sites in order to determine seasonal fluctuations in both 14 C and 13 C isotope composition. Unexpectedly low δ13 C values have been obtained about (-25±2)0/00 instead of expected (-7±1)0/00. Such low values have been attributed to the carbon isotope fractionation during the CO 2 absorption on the highly alkaline medium because of

  18. The synthesis of nucleoside bases with 14 C

    International Nuclear Information System (INIS)

    Matloubi, H.; Mehrdad, M.

    1997-01-01

    Labelled organic compounds have been widely and diligently applied to research problems in life science and chemistry. In many laboratories they have lost their novelty and have been become conventional research tools since long time ago. these applications frequently require organic compounds substituted (or labelled) with isotopes, but the isotopes are (with certain exception) extracted in first place in simple inorganic forms. The conversion of these simple form into the more or less complex labelled compounds called for by research workers has become in effect a new branch of practical organic chemistry. The preparation of labelled compounds, carbon-14 is probably more extensively and variously used than any other isotope. It emits only beta-particles. In this project, two kinds of nucleoside bases under the name uracil-2- 14 C and thymine (methyl- 14 C) were prepared.(author). 14 refs., 3 figs., 2 tabs

  19. New proportional counter assembly in Gliwice 14C laboratory

    International Nuclear Information System (INIS)

    Moscicki, W.; Zastawny, A.

    1977-01-01

    The design and parameters are described of a proportional counter for low level counting. The cathode tube 80 mm in diameter and 30 cm in length is made of pure copper. The anode is a tungsten wire 0.05 mm in diameter. The cathode tube is surrounded by a cylindrical ring container with mercury. The total volume of the counter is 1.5 l and it is filled with carbon dioxide. At a pressure of 1 at of CO 2 the counter background is 4.20+-0.05 cpm and contemporary 14 C net effect 10.22+-0.10 cpm; at a pressure of 2 at of CO 2 the background is 4.40+-0.05 cpm and the contemporary 14 C net effect 20.53+-10 cpm. The efficiency of the proportional counter is 88% in both cases. (J.B.)

  20. Spectrophotometric determination of sugars labelled with 14C

    International Nuclear Information System (INIS)

    Vatsikova, A.; Kralikova, M.; Vyskochilova, Z.

    1982-01-01

    Comparative analysis of methods for determination of microgram amounts of 14 C-labelled sugars has been carried out. The ferricyanide and Shomodyi-Nelson methods were approbated in experimental study. The relative error of the ferricyanide method was found to be smaller than that of the Shomodyi-Nelson method. Thus the ferricyanide method was used for obtaining calibration curves for 15 sugars. The accuracy for sugar amounts higher than 3 μg/10 ml was better than +, - 5% [ru

  1. Translocation of 14-C in ponderosa pine seedlings

    Science.gov (United States)

    Robert R. Ziemer

    1971-01-01

    The movement of 14-C from the old needles to the roots, and later to the new needles, was measured in 2-year-old ponderosa pine seedlings. The seedlings were in one of three growth stages at the time of the feeding of 14-CO-2: 9 days before spring bud break with no root activity; 7 days before spring bud break with high root activity; and 7 days after spring bud break...

  2. Degradation of 14C-glyphosate in compost amended soils.

    Science.gov (United States)

    Alexa, E; Bragea, M; Sumalan, R; Negrea, M; Lazureanu, A

    2009-01-01

    Glyphosate (N-phosphonomethyl-glycine), the active ingredient in several herbicide formulations, is a non-selective, post-emergent herbicide used in a variety of crop and non-crop situations. Glyphosate is a non-volatile herbicide that is relatively immobile in soil. Its degradation is due to microbiological processes and most laboratory studies have been conducted with 14C-glyphosate with the rate of 14CO2 evolution being used as an indication of herbicide breakdown. In this paper we have studied the glyphosate degradation in compost amendment soils using Scientilator Liquid TRIATHLER and Glyphosate-phosphonomethyl-14C-labeled with specific activity 2,2mCi/mmol. Four types of soils have been taken under study: Black Chernozem, Vertisol, Gleysol and Phaeozem with different characteristics. For the each type of soil have been realized four experimental variants (glyphosate blind sample with 1,5 ppm, concentration, autoclaved soil, soil with glyphosate and addition of compost in field concentration of 40 t/ha, respectively 60 t/ha. The mineralization curves of 14CO2 accumulated were compared during of 40 days. All the mineralization curves for the soils exhibited same patterns, with only two phases, the initial rapid phase of degradation, for about 20 days, attributed to microbial action on the free glyphosate and the second slow phase, when the curves attained plateaus. Compost applied with different concentrations to Vertisol and Black Chernozem did not appear to stimulate the microbial degradation of glyphosate. In Gleysol and Phaeozem with lower humus content, the mineralization curve of 14C indicate the increase degradation capacity, expressed as accumulated 14CO2 as % total 14C, with the increase of compost concentration.

  3. Residues of 14C-paclobutrazol in mangoes

    International Nuclear Information System (INIS)

    Costa, Maria A.; Tornisielo, Valdemar L.; Castanho, Giuliane M.

    2009-01-01

    Paclobutrazol (PBZ) is a growth regulator used in agricultural systems whose purpose is the control of vegetative growth, stimulating the reproductive capacity of plants. This growth regulator remains active in soil for a long time and its half-life varies with the type of soil and climatic conditions, can severely affect the development of crops. This work aimed to study the residues / metabolites of 14 C-PBZ in mango pulp Tommy Atkins. The tests were performed with mangoes grown in pots stainless steel and application of 14 C-PBZ was performed by the soil projection of the crown, and the mangoes tested in two periods, one year and two years after application. To evaluate the levels of residues of 14 C-PBZ was realize the burning of 200 mg of pulp on biological oxidized and detached 14 CO 2 was detected by liquid scintillation spectrophotometer. The results were 1.65 % of residue of PBZ on fruit collected after two years of application and 4.30 % of residue of PBZ collected on fruit after a year of application and also can see that the product remained in the soil for more than one year, is translocated to the plant and reach the edible part, the pulp fruit. The identification of residual 14 C- PBZ/metabolites by thin-layer chromatography did not reveal any pattern of PBZ / metabolites due to the low activity detected in the samples. Therefore, another procedure was performed for extraction and then analyzed by high performance liquid chromatography (HPLC) for detection of metabolites in the PBZ of mango pulp. (author)

  4. The study of variations and environmental applications 14C

    International Nuclear Information System (INIS)

    Simon, J.

    2010-01-01

    The primary aim of the presented thesis is to explain experimentally observed 14 C variations in the outer atmosphere. Physical models have been developed to quantify directly immeasurable phenomena relevant in the field of radiocarbon dynamics. Namely atmospheric stability, 14 C transport from the stratosphere to the lower troposphere and fossil carbon dioxide emissions to the atmosphere. Finally these models have been used as the pillars of the united theory of Δ 14 C dynamics. Besides the presented main theoretical outputs, this thesis also provides couple of potentially implementable by-products. First of them is a method to evaluate so called 'equivalent mixing height' and turbulent diffusion coefficient using temporal changes of 222 Rn concentration in the boundary layer of the atmosphere. The elaborated mathematical apparatus for the evaluation of aerosol scavenging by raindrops can be utilized in the models of pollutant dispersion. Information on turbulent diffusion coefficient at higher atmospheric levels is important for the models of stratospheric and ozonospheric dynamics. Nowadays, when one can measure and even feel the greenhouse effect consequences, the importance of an independent method for carbon dioxide fossil emissions assessment is obvious. Besides theoretical outcome, the thesis also presents experimental results. A network of CO 2 sampling sites has been established in Bratislava and the outskirts in the vicinity of the town. Together with mountain site Chopok the network brought a unique information on 14 C distribution. Atmospheric measurements of 7 Be and 222 Rn activity are also presented here. Finally the PC codes have been developed to bridge a gap between experimental and theoretical results. (author)

  5. Pediatric microdose and microtracer studies using 14C in Europe.

    Science.gov (United States)

    Turner, M A; Mooij, M G; Vaes, W H J; Windhorst, A D; Hendrikse, N H; Knibbe, C A J; Kõrgvee, L T; Maruszak, W; Grynkiewicz, G; Garner, R C; Tibboel, D; Park, B K; de Wildt, S N

    2015-09-01

    Important information gaps remain on the efficacy and safety of drugs in children. Pediatric drug development encounters several ethical, practical, and scientific challenges. One barrier to the evaluation of medicines for children is a lack of innovative methodologies that have been adapted to the needs of children. This article presents our successful experience of pediatric microdose and microtracer studies using (14) C-labeled probes in Europe to illustrate the strengths and limitations of these approaches. © 2015 ASCPT.

  6. Residues of {sup 14}C-paclobutrazol in mangoes

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Maria A.; Tornisielo, Valdemar L.; Castanho, Giuliane M., E-mail: macosta@cena.usp.b [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil). Lab. de Ecotoxicologia

    2009-07-01

    Paclobutrazol (PBZ) is a growth regulator used in agricultural systems whose purpose is the control of vegetative growth, stimulating the reproductive capacity of plants. This growth regulator remains active in soil for a long time and its half-life varies with the type of soil and climatic conditions, can severely affect the development of crops. This work aimed to study the residues / metabolites of {sup 14}C-PBZ in mango pulp Tommy Atkins. The tests were performed with mangoes grown in pots stainless steel and application of {sup 14}C-PBZ was performed by the soil projection of the crown, and the mangoes tested in two periods, one year and two years after application. To evaluate the levels of residues of {sup 14}C-PBZ was realize the burning of 200 mg of pulp on biological oxidized and detached {sup 14}CO{sub 2} was detected by liquid scintillation spectrophotometer. The results were 1.65 % of residue of PBZ on fruit collected after two years of application and 4.30 % of residue of PBZ collected on fruit after a year of application and also can see that the product remained in the soil for more than one year, is translocated to the plant and reach the edible part, the pulp fruit. The identification of residual {sup 14}C- PBZ/metabolites by thin-layer chromatography did not reveal any pattern of PBZ / metabolites due to the low activity detected in the samples. Therefore, another procedure was performed for extraction and then analyzed by high performance liquid chromatography (HPLC) for detection of metabolites in the PBZ of mango pulp. (author)

  7. XCAMS: The compact "1"4C accelerator mass spectrometer extended for "1"0Be and "2"6Al at GNS Science, New Zealand

    International Nuclear Information System (INIS)

    Zondervan, A.; Hauser, T.M.; Kaiser, J.; Kitchen, R.L.; Turnbull, J.C.; West, J.G.

    2015-01-01

    Highlights: • We review the performance of a 0.5 MV AMS system for "1"0Be, "1"4C, and "2"6Al. • We identify the limiting factors to "1"0Be machine blank and detection efficiency. • We discuss an AMS data reduction method that accounts for non-Poisson uncertainty. - Abstract: A detailed description is given of the 0.5 MV tandem accelerator mass spectrometry (AMS) system for "1"0Be, "1"4C, "2"6Al, installed in early 2010 at GNS Science, New Zealand. Its design follows that of previously commissioned Compact "1"4C-only AMS (CAMS) systems based on the Pelletron tandem accelerator. The only basic departure from that design is an extension of the rare-isotope achromat with a 45° magnet and a two-anode gas-ionisation detector, to provide additional filtering for "1"0Be. Realised performance of the three AMS modes is discussed in terms of acceptance-test scores, "1"4C Poisson and non-Poisson errors, and "1"0Be detection limit and sensitivity. Operational details and hardware improvements, such as "1"0Be beam transport and particle detector setup, are highlighted. Statistics of repeat measurements of all graphitised "1"4C calibration cathodes since start-up show that 91% of their total uncertainty values are less than 0.3%, indicating that the rare-isotope beamline extension has not affected precision of "1"4C measurement. For "1"0Be, the limit of detection in terms of the isotopic abundance ratio "1"0Be/"9Be is 6 × 10"−"1"5 at at"−"1 and the total efficiency of counting atoms in the sample cathode is 1/8500 (0.012%).

  8. XCAMS: The compact {sup 14}C accelerator mass spectrometer extended for {sup 10}Be and {sup 26}Al at GNS Science, New Zealand

    Energy Technology Data Exchange (ETDEWEB)

    Zondervan, A., E-mail: a.zondervan@gns.cri.nz [GNS Science, Lower Hutt (New Zealand); Hauser, T.M. [National Electrostatics Corporation, Middleton, WI (United States); Kaiser, J. [GNS Science, Lower Hutt (New Zealand); Kitchen, R.L. [National Electrostatics Corporation, Middleton, WI (United States); Turnbull, J.C.; West, J.G. [GNS Science, Lower Hutt (New Zealand)

    2015-10-15

    Highlights: • We review the performance of a 0.5 MV AMS system for {sup 10}Be, {sup 14}C, and {sup 26}Al. • We identify the limiting factors to {sup 10}Be machine blank and detection efficiency. • We discuss an AMS data reduction method that accounts for non-Poisson uncertainty. - Abstract: A detailed description is given of the 0.5 MV tandem accelerator mass spectrometry (AMS) system for {sup 10}Be, {sup 14}C, {sup 26}Al, installed in early 2010 at GNS Science, New Zealand. Its design follows that of previously commissioned Compact {sup 14}C-only AMS (CAMS) systems based on the Pelletron tandem accelerator. The only basic departure from that design is an extension of the rare-isotope achromat with a 45° magnet and a two-anode gas-ionisation detector, to provide additional filtering for {sup 10}Be. Realised performance of the three AMS modes is discussed in terms of acceptance-test scores, {sup 14}C Poisson and non-Poisson errors, and {sup 10}Be detection limit and sensitivity. Operational details and hardware improvements, such as {sup 10}Be beam transport and particle detector setup, are highlighted. Statistics of repeat measurements of all graphitised {sup 14}C calibration cathodes since start-up show that 91% of their total uncertainty values are less than 0.3%, indicating that the rare-isotope beamline extension has not affected precision of {sup 14}C measurement. For {sup 10}Be, the limit of detection in terms of the isotopic abundance ratio {sup 10}Be/{sup 9}Be is 6 × 10{sup −15} at at{sup −1} and the total efficiency of counting atoms in the sample cathode is 1/8500 (0.012%).

  9. Biodegradation of 14 C-atrazine under outdoor conditions

    International Nuclear Information System (INIS)

    Queiroz, Brigida Pimentel Villar de

    1997-10-01

    Uniformly 14 C-ring labeled atrazine (5 L/ha) was applied to a Typical Hapludox Brazilian Soil sample which was incubated under outdoor conditions. Sample of 200 g (dry weight base) of fresh soil were distributed in Erlenmeyer flasks and the moisture was adjusted for 2/3 rds of the soil field capacity. The flasks were then buried in the Lysimeter Station when they were incubated. The experiment started jointly with a corn planting. The 14 C O 2 was analyzed every 15 day, during a period of 150 days. The desorbed, extracted and bound residues were analyzed. The extracted soil was fractionated and the residues in the humin, fulvic and humic acids were determined. At the end of the incubation period (150 days), the 14 CO 2 evolved reached up to 36% of the total applied activity, the bound residues were detected in about the same (34%) during the inoculation period, and were distributed in the fractions of fulvic acids (29,91%), humic acids (6,83%) and humin (63,26%). The metabolites formed in the desorbed residues and in the extracted residues were determined using thin layer chromatography with 14 C-detector. After 150 days incubation, desorbed soil residues were identified as atrazine (52,72%), hydroxiatrazine (44%) and desisopropilatrazine (3,28%). The extractable residues contained atrazine (79,29%), hydroxiatrazine (16,22%), desisopropilatrazine (2,25%) and desetylatrazine (2,24%). (author)

  10. Behaviour of 14C-DDT in Sudan Gezira soil

    International Nuclear Information System (INIS)

    Abdalla, A.M.; El-Zorgani, G.A.

    1988-01-01

    Field cylinders as described in the model experiment for determination of 14 C-DDT in Sudan Gezira soil were prepared and samples were collected for determination of 14 C-activity at various intervals. About 83-87% of the applied radioactivity was recovered in the extracts from the top 10 cm layer of soil. The loss rate of the chemical from soil increased with time apparently by volatilization and thermal degradation due to high soil temperature, intensive solar radiation and low soil organic matter. This resulted in a half-life of approx. 5 weeks. The major part of the chemical and possible metabolites were detected in the top 10 cm layer. Approximately 8-10% of the applied 14 C was detected in samples collected after 16-20 weeks. TLC and autoradiography indicated the presence of p,p'-DDT and p,p'-DDE as the major metabolite. Also traces of TDE were detected in some samples. These results showed that under Sudanese tropical conditions, DDT dissipates very rapidly in soils compared to dissipation in temperate regions. (author). 6 refs, 2 tabs

  11. Synthesis of 14C-labelled α-methyl tyrosine

    International Nuclear Information System (INIS)

    Rajagopal, S.; Venkatachalam, T.K.; Conway, T.; Diksic, M.

    1992-01-01

    A new route for the preparation of radioactively labelled α-methyl L-tyrosine is described. The labelling at the α position has been successfully achieved with 14 C-, 11 C- (very preliminary, unpublished), and 3 H-labelled methyl iodide. A detailed report on 14 C-labelling at the α position and the hydrolysis of 4-methoxy α-methyl phenylalanine is presented. The alkylation proceeds via the methylation of the carbanion of N-benzylidene 4-methoxy phenylalanine methyl ester 2. Hydrolysis of 4-O methyl tyrosine to tyrosine by HBr and HI were analysed and used in the optimization of the hydrolysis conditions of 4. Enantiomeric purity of the isolated L-isomer has been found to be 99% as judged by HPLC. Pseudo first-order rate constant for the hydrolysis of 14 C-labelled α-methyl 4-methoxy phenyl alanine methyl ester was determined. Preliminary findings of the 3 H- and 11 C-radiolabelled α-methyl tyrosine (methyl labelled) are also mentioned. For the first time it was shown that α-methyl D,L-tyrosine can be separated into enantiomerically pure α-methyl D- and L-tyrosine using a CHIRALPAK WH column. (author)

  12. Benzene Synthesis for ''14C Measurements and Evaluation of Uncertainty in Mollusk Shells; Sintesis de Benceno para la Determinacion de C''14 y Evaluacion de su Incertidumbre en Conchas de Moluscos

    Energy Technology Data Exchange (ETDEWEB)

    Romero del Hombrebueno, B.; Simon, M. A.; Larena, P.

    2002-07-01

    This work describes the method and instrumentation used by Environmental Isotopes laboratory of the CIEMAT Analytical Chemistry Laboratory (DIAE) for the synthesis of benzene from carbonates of mollusk shells and the liquid scintillation counting of ''14C for radiocarbon dating in these samples. The usefulness of mollusk shells for ''14 C dating are considered. (Author)

  13. Synthesis of disodium [benzene-U-{sup 14}C]-(4-chlorophenylthio)methylenediphosphonate, [benzene-U-{sup 14}C]-tiludronate

    Energy Technology Data Exchange (ETDEWEB)

    Burgos, Alain; Ellames, G.J. [Alnwick Research Centre (United Kingdom). Dept. of Metabolism and Pharmacokinetics

    1995-12-31

    Disodium [benzene-U-{sup 14}C]-(4-chlorophenylithio)methylenediphosphonate, [benzene-{sup 14}C]-Tiludronate, 2, has been prepared in six steps from [benzene-U-{sup 14}C]-acetanilide in an overall radiochemical yield of 41%. A key step in this transformation was the efficient conversion of [U-{sup 14}C]-4-chloroaniline to [benzene-U-{sup 14}C]-4-chlorophenylthiocyanate, 5, in 83% yield by treatment of the corresponding diazonium salt, 9 with iron(111) thiocyanate. It should be noted that formation of the isomeric [benzene-U-{sup 14}C]-4-chlorophenylisothiocyanate, 11, as a byproduct, was observed in only {approx} 1% yield. (author).

  14. New Technique Of Determination Of Biogenic Fraction In Liquid Fuels By The 14C Method

    International Nuclear Information System (INIS)

    Krajcar Bronic, I.; Baresic, J.; Horvatincic, N.; Kristof, R.; Kozar Logar, J.

    2015-01-01

    According to the EU Directive 2009/28/EC all (liquid) fuels have to contain at least 10 percent of bio-fuel, i.e., blend of biogenic origin, by 2020. 14C method is the most reliable method of determination of the biogenic fraction in fuels and various measurement techniques can be applied. A technique of direct measurement of the 14C content in liquid fuel is simple and fast but has main disadvantage: different liquid colours cause different quenching and changes in the measurement efficiency. Here we have described a new technique that uses liquids of different colours to construct modern and background calibration curves, MCC and BCC, respectively, by measuring count rates and SQP values of various modern and fossil liquids. Several types of fossil fuel, pure benzine and benzene (used as 14C-free background for 14C dating) were used for BCC, and various brands of domestic oil (vegetable, sunflower, olive, pumpkin), bioethanol and benzene prepared from modern samples were used MCC construction. The procedure for the unknown sample consists of: 1) measurement of the count rate and the SQP value, 2) calculation of background and modern count rates corresponding to the measured SQP value based on the BCC and MCC curves, respectively, and 3) the ratio of net count rates of the unknown sample and the modern net count rate at the same SQP represents the fraction of the biogenic component in the liquid. All samples should be measured under the same conditions. In our case these are: UltimaGold F scintillator, the ratio sample:scintillator (10 mL:10 mL), low-potassium glass vials of 20 mL volume, spectra recorded by LSC Quantulus and evaluated in the window 124 - 570. Lowest detectable biogenic fraction is 0.5 %. The technique depends neither on the fossil matrix or the biogenic additive types. The results are in good agreement with those obtained by different evaluation technique. (author).

  15. Uptake of [2-14C]abscisic acid and distribution of 14C in apple embryos

    International Nuclear Information System (INIS)

    Barthe, P.; Bulard, C.

    1981-01-01

    Pyrus malus L. var. Golden delicious embryos were incubated with (+-)-[2- 14 C] abscisic acid (ABA). After incubations of various durations, the radioactivity was measured in whole embryos, cotyledons, and embryonic axes. With either 48-h or 16-d incubation periods, the uptake of [ 14 C] ABA depended upon the mode of culture used. The lowest values corresponded to the absorption by the embryonic axis, the highest to the absorption by the distal parts of the two cotyledons. The cotyledons accumulated the main part of the radioactivity under all conditions. Dormant and almost completely after-ripened embryos cultivated for 4 d showed no significant differences in the radioactivity uptake for identical modes of culture. There was a linear relationship between exogenous ABA concentrations (0.5 to 3.10 -5 M) and ABA uptake for embryos cultivated for 4 d with the distal parts of the cotyledons immersed in the medium. (orig.) [de

  16. Uptake of (2-/sup 14/C)abscisic acid and distribution of /sup 14/C in apple embryos

    Energy Technology Data Exchange (ETDEWEB)

    Barthe, P.; Bulard, C.

    1981-01-01

    Pyrus malus L. var. Golden delicious embryos were incubated with (+-)-(2-/sup 14/C) abscisic acid (ABA). After incubations of various durations, the radioactivity was measured in whole embryos, cotyledons, and embryonic axes. With either 48-h or 16-d incubation periods, the uptake of (/sup 14/C) ABA depended upon the mode of culture used. The lowest values corresponded to the absorption by the embryonic axis, the highest to the absorption by the distal parts of the two cotyledons. The cotyledons accumulated the main part of the radioactivity under all conditions. Dormant and almost completely after-ripened embryos cultivated for 4 d showed no significant differences in the radioactivity uptake for identical modes of culture. There was a linear relationship between exogenous ABA concentrations (0.5 to 3.10/sup -5/ M) and ABA uptake for embryos cultivated for 4 d with the distal parts of the cotyledons immersed in the medium.

  17. Metabolism of U14C palmitic and 1-14C caproic acids by lettuce seeds during early germination

    International Nuclear Information System (INIS)

    Salon, C.; Raymond, P.; Pradet, A.

    1986-01-01

    Germinating lettuce embryos (before radicule emergence) were fed with either U 14 C palmitic acid or 1 14 C caproic acid until a metabolic steady state was reached. The bulk of labelled caproate was evolved as respiratory CO 2 (52%) and incorporated into organic and amino acids (38%) and only a small part incorporated into lipids whereas most of labelled palmitic acid was found into lipids (92%) and only 8% evolved as CO 2 and incorporated into organic and amino acids. The label distribution at steady state in intermediates linked to the T.C.A. cycle was interpreted using a metabolic model. They found that the two fatty acids were degraded by β-oxidation and incorporated into the T.C.A. cycle as acetylCoA suggesting that β-oxidation is located in the mitochondria. The results also indicate that lipids contribute for at least 90% to the carbon supply to respiration

  18. Autoradiography of [14C]paraquat or [14C]diquat in frogs and mice: accumulation in neuromelanin

    International Nuclear Information System (INIS)

    Lindquist, N.G.; Larsson, B.S.; Lyden-Sokolowski, A.

    1988-01-01

    The herbicide paraquat has been suggested as a causative agent for Parkinson's disease because of its structural similarity to a metabolite of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), which may induce a parkinsonism-like condition. MPTP as well as its metabolite 1-methyl-4-phenylpyridine have melanin affinity, and the parkinsonism-inducing potency of MPTP is much stronger in species with melanin in the nerve cells. Autoradiography of [ 3 H]MPTP in experimental animals has shown accumulation in melanin-containing tissues, including pigmented neurons. In the present whole body autoradiographic study accumulation and retention was seen in neuromelanin in frogs after i.p. injection of [ 14 C]paraquat or[ 14 C]diquat. By means of whole body autoradiography of [ 14 C]diquat in mice (a species with no or very limited amounts of neuromelanin) a low, relatively uniformly distributed level of radioactivity was observed in brain tissue. Accumulation of toxic chemical compounds, such as paraquat, in neuromelanin may ultimately cause lesions in the pigmented nerve cells, leading to Parkinson's disease

  19. Autoradiography of ( sup 14 C)paraquat or ( sup 14 C)diquat in frogs and mice: accumulation in neuromelanin

    Energy Technology Data Exchange (ETDEWEB)

    Lindquist, N G; Larsson, B S; Lyden-Sokolowski, A [Uppsala Univ., Biomedical Center, (Sweden). Dept. of Toxicology

    1988-10-31

    The herbicide paraquat has been suggested as a causative agent for Parkinson's disease because of its structural similarity to a metabolite of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), which may induce a parkinsonism-like condition. MPTP as well as its metabolite 1-methyl-4-phenylpyridine have melanin affinity, and the parkinsonism-inducing potency of MPTP is much stronger in species with melanin in the nerve cells. Autoradiography of ({sup 3}H)MPTP in experimental animals has shown accumulation in melanin-containing tissues, including pigmented neurons. In the present whole body autoradiographic study accumulation and retention was seen in neuromelanin in frogs after i.p. injection of ({sup 14}C)paraquat or({sup 14}C)diquat. By means of whole body autoradiography of ({sup 14}C)diquat in mice (a species with no or very limited amounts of neuromelanin) a low, relatively uniformly distributed level of radioactivity was observed in brain tissue. Accumulation of toxic chemical compounds, such as paraquat, in neuromelanin may ultimately cause lesions in the pigmented nerve cells, leading to Parkinson's disease.

  20. Practical synthesis of 14C S-ribosyl-L-homocysteine uniformly labelled on the sugar moiety. An enzymatic route from (U-14C) adenosine

    International Nuclear Information System (INIS)

    Guillerm, G.; Allart, B.

    1992-01-01

    [(U- 14 C) S-Ribosyl]-L-homocysteine has been prepared enzymatically from (U- 14 C) adenosine in two steps using S-adenosyl homocysteine hydrolase and bacterial S-adenosyl homocysteine nucleosidase as catalysts. (Author)

  1. A study of the reactions 14C( vector d, dprime)14C and 14C ( vector d, p)15C at 16.0 MeV

    International Nuclear Information System (INIS)

    Murillo, G.; Sen, S.; Darden, S.E.

    1994-01-01

    Cross-section and vector-analyzing-power measurements for 14 C(d, d prime) and 14 C(d, p) reactions have been carried out for E d =16 MeV. The inelastic-scattering data have been analyzed using the DWBA with a collective and a microscopic model form-factor and also by using the coupled-channels formalism with a vibrational model form-factor. It is observed that while the cross-section angular-distribution data for the two 2 + states at E x =7.012 and 8.318 MeV are very similar, the corresponding vector analyzing powers are quite different. The results of the analyses indicate that the distinctive characteristics probably arise from the difference in the relative importance of the proton and neutron components in the transition amplitude. The 3 - state at E x =6.728 MeV is identified as predominantly a 1p-3h state. Although the deformation parameters are relatively large, the single-particle structure aspects play a more dominant role than channel-coupling effects in populating the inelastic states. The transfer reaction data have been analyzed using the DWBA for bound and unbound states. The importance of two-step processes has been investigated via coupled-reaction-channels calculations. The g.s. and the states with excitation energies 0.770, 3.103 and 4.78 MeV in 15 C are populated primarily by a one-step process with a small two-step contribution in the case of the 3.103 MeV state. The 4.22 MeV state is populated predominantly by two-step processes. The 4.78 and the 5.83 MeV states have been identified as 1p-2h and 3p-4h, [3]/[2] + state, respectively, in an earlier report. There is close similarity in the level structures and reaction mechanisms between the states of 15 C and 17 O populated via the (d, p) reaction. ((orig.))

  2. 14C-Methylenebisphenylisocyanate (14C-MDI). Study of absorption after single dermal and intradermal administration in rats

    International Nuclear Information System (INIS)

    Leibold, E.; Hoffmann, H.D.; Hildebrand, B.

    1999-01-01

    The absorption, distribution and excretion of radioactivity was studied in groups of four male Wistar rats following a single dermal and intradermal administration of 14 C- Methylenebisphenylisocyanate ( 14 C-MDI) at nominal dose levels of 4.0 and 0.4 mg/cm 2 for dermal administration and 0.4 mg/animal for intradermal administration. These dose levels nominally corresponded to 40 and 4.0 mg/animal for dermal administration. Considering the animal weights, dose levels corresponded to about 140 and 14 mg/kg body weight (dermal administration) and 1.4 mg/kg body weight (intradermal administration). In the experiments with dermal administration, animals were exposed for 8 hours and sacrificed 8, 24 or 120 h after beginning of exposure. In the experiment with intradermal administration, animals were sacrificed 120 h after treatment. After dermal administration of 14 C-MDI, mean recoveries of radioactivity from all dose groups were in the range from 97.86 to 108.07% of the total radioactivity administered. Generally, the largest proportion of radioactivity was found at the application site and dressing. The total amount of radioactivity absorbed (including excreta, cage wash, tissues/organs and carcass) increased with increasing sacrifice time. Dermal absorption was very low and quantitatively similar at both dose levels; maximally ca. 0.9 % of the applied radioactivity was absorbed. After intradermal administration of 14 C-MDI, the mean recovery of radioactivity was 100.90 % of the radioactivity administered. The largest proportion of radioactivity was found at the application site. The total amount of radioactivity absorbed (including excreta, cage wash, tissues/organs and carcass) amounted to about 26 % of the radioactivity applied. Irrespective of the mode of administration of 1 4C -MDI, concentrations of radioactivity in tissues and organs generally were below 1 μg Eq/g at 120 h after administration. In summary, the results of this study comparing systemic

  3. Synthesis of 1-benzyl-4-[(5,6-dimethoxy[2-14C]-1-indanon)-2-YL]-methylpiperidine hydrochloride (E2020-14C)

    International Nuclear Information System (INIS)

    Iimura, Youichi; Mishima, Mannen; Sugimoto, Hachiro

    1989-01-01

    1-Benzyl-4-[(5,6-dimethoxy[2- 14 C]-1-indanon)-2-yl]-methylpiperidine hydrochloride (E2020- 14 C), and acetylcholinesterase inhibitor for studying the pharmacokinetic profiles of E2020, was synthesized from 5,6-dimethoxy[2- 14 C]-1-indanone as the labelled starting material. (author)

  4. Synthesis of 1-benzyl-4-((5,6-dimethoxy(2- sup 14 C)-1-indanon)-2-YL)-methylpiperidine hydrochloride (E2020- sup 14 C)

    Energy Technology Data Exchange (ETDEWEB)

    Iimura, Youichi; Mishima, Mannen; Sugimoto, Hachiro (Eisai Co., Ltd., Ibaraki (Japan). Tsukuba Research Labs.)

    1989-07-01

    1-Benzyl-4-((5,6-dimethoxy(2-{sup 14}C)-1-indanon)-2-yl)-methylpiperidine hydrochloride (E2020-{sup 14}C), and acetylcholinesterase inhibitor for studying the pharmacokinetic profiles of E2020, was synthesized from 5,6-dimethoxy(2-{sup 14}C)-1-indanone as the labelled starting material. (author).

  5. Combustion synthesis of ceramic matrices for immobilization of 14C

    International Nuclear Information System (INIS)

    Bosc-Rouessac, F.; Marin-Ayral, R.M.; Haidoux, A.; Massoni, N.; Bart, F.

    2008-01-01

    In this study, the use of combustion synthesis for immobilization of 14 C was considered. Ceramic matrices have been prepared by this method using two different devices: one non-conventional with preheating of the samples and the other conventional device where ignition was produced thanks to tungsten filament. These two devices gave rise to different mechanisms of reactions involving different amounts of unreacted carbon graphite inside the matrix. The SHS samples were characterized by using scanning electron microscopy (SEM) and X-ray diffraction (XRD)

  6. Studies on 14C labelled chlorpyrifos in model marine ecosystem

    International Nuclear Information System (INIS)

    Pandit, G.G.; Mohan Rao, A.M.; Kale, S.P.; Murthy, N.B.K.; Raghu, K.

    1997-01-01

    Chlorpyrifos is one of the widely used organophosphorus insecticides in tropical countries. Experiments were conducted with 14 C labelled chlorpyrifos to study the distribution of this compound in model marine ecosystem. Less than 50 per cent of the applied activity remained in water in 24 h. Major portion of the applied chlorpyrifos (about 4.2 % residue per g) accumulated into the clams with sediment containing a maximum of 5 to 6 per cent of applied compound. No degradation of chlorpyrifos was observed in water or sediment samples. However, metabolic products were formed in clams. (author). 4 refs., 3 tabs

  7. Synthesis of /sup 14/C-labelled butoxyethoxyethanol

    Energy Technology Data Exchange (ETDEWEB)

    Thijssen, J.B.A.; Janssen, C.G.M.; Verluyten, W.L.M.; Heykants, J.J.P.

    1986-02-01

    Butoxyethoxyethanol, an organic solvent used as carrier in the levamisole pour-on formulation, was synthesized via a Makosza etherification of 1-/sup 14/C-labelled bromobutane with mono tetrahydropyranyl (T.H.P.) protected diethylene glycol and subsequent removal of the T.H.P. protecting group. The compounds' synthetic yield was 88.8%; it had a specific activity of 32.5 mCi/mmol. The reaction product was radiochemically pure (99.6%) according to high-performance liquid chromatography and thin-layer chromatography in three solvent systems.

  8. The synthesis of 2-14C-N-nitrosothiazolidine

    International Nuclear Information System (INIS)

    Cragin, D.W.; Shibamoto, Takayuki

    1989-01-01

    2- 14 C-N-Nitrosothiazolidine was synthesized with a chemical purity of 99.6%, a radio chemical purity of 99.4%, and an overall yield of 30.7%. Unlabelled N-nitrosothiazolidine, synthesized using the same method, resulted in a purity of 99.85% by capillary GC and 99.7% by HPLC. Analysis of N-nitrosothiazolidine by GC was found to require a low injection port temperature of 160 0 C to prevent denitrosation in the injection port. During the nitrosation of thiazolidine, if the pH was reduced below 4 with hydrochloric acid, ring hydrolysis occurred, and chlorinated disulfide compounds formed. (author)

  9. Chemical radiolabeling of carboxyatractyloside by [14C]acetic anhydride

    International Nuclear Information System (INIS)

    Block, M.R.; Pougeois, R.; Vignais, P.V.

    1980-01-01

    The authors report the synthesis and biological properties of a radiolabeled derivative of CAT obtained with acetylation of the primary alcohol of CAT with radiolabeled acetic anhydride. They also investigate the question of mutual exclusion of CAT and BA for binding to the mitochondrial ADP/ATP carrier in double labeling experiments based on the use of [ 3 H]BA and [ 14 C]Ac-CAT. The results are consistent with the view that the ADP/ATP carrier possesses two separate interacting binding sites for AT (or CAT) and for BA. (Auth.)

  10. Application of 14C to physiological studies of insects

    International Nuclear Information System (INIS)

    Yamashita, Okitsugu

    1977-01-01

    The specificity of insects which has been resolved as a result of using tracers such as 14 C etc. and the metabolic ground of vital condition which is not observed in other biotic groups were discussed. As for carbohydrate metabolism, trehalose metabolism, the relation between formation of polyhydric alcohol and quiescence, and energy production system were mentioned. As for lipid metabolism, mobilization of diglyceride among tissues, purification and properties of diglyceride-carrying lipoprotein, and the physiological action of lipoprotein were cited. The specific metabolisms of insects were summarized from the viewpoints of energy production and its distribution mechanism in vivo. (Ichikawa, K.)

  11. Decay counting in the age of AMS

    International Nuclear Information System (INIS)

    Arnold, J.R.

    1987-01-01

    Up to the advent of AMS, all the accomplishments of 14 C dating, and the studies of 10 Be and other long-lived radionuclides, were made by low-level decay counting, the technique pioneered by W.F. Libby. It will hardly be news to people at this conference that, while much was accomplished in the three decades when counting prevailed, the world has now changed decisively. I will try to give an account of where low-level counting was 'before the revolution', and of what its usefulness is today. There are still some remarkable examples of its application, the best being the neutrino experiment of Raymond Davis, and its potential successors. Some cosmogenic nuclides, whose half-lives are less than 10 3 yr, are still best measured by decay; this will continue unless the overall ion yield of AMS systems rises markedly from present levels. One long-lived nuclide, 53 Mn, is still best measured by neutron activation as 312-day 54 Mn, but this may not continue. (orig.)

  12. Decay counting in the age of AMS

    International Nuclear Information System (INIS)

    Arnold, J.R.

    1987-01-01

    Up to the advent of AMS, all the accomplishments of 14 C dating, and the studies of 10 Be and other long-lived radionuclides, were made by low-level decay counting, the technique pioneered by W.F. Libby. It will hardly be news to people at this conference that, while much was accomplished in the three decades when counting prevailed, the world has now changed decisively. He will try to give an account of where low-level counting was before the revolution, and of what its usefulness is today. There are still some remarkable examples of its application, the best being the neutrino experiment of Raymond Davis, and its potential successors. Some cosmogenic nuclides, whose half-lives are less than 10 3 yr, are still best measured by decay; this will continue unless the overall ion yield of AMS systems rises markedly from present levels. One long-lived nuclide, 53 Mn, is still best measured by neutron activation as 312-day 54 Mn, but this may not continue

  13. A novel tertiary prep-HPLC method for the isolation of single amino acids for AMS-radiocarbon measurement.

    Science.gov (United States)

    Fernandes, Ricardo; Koudelka, Tomas; Tholey, Andreas; Dreves, Alexander

    2017-07-15

    AMS-radiocarbon measurements of amino acids can potentially provide more reliable radiocarbon dates than bulk collagen analysis. Nonetheless, the applicability of such an approach is often limited by the low-throughput of existing isolation methods and difficulties in determining the contamination introduced during the separation process. A novel tertiary prep-HPLC amino acid isolation method was developed that relies on the combustion of eluted material without requiring any additional chemical steps. Amino acid separation was carried out using a gradient mix of pure water and phosphoric acid with an acetonitrile step in-between runs to remove hydrophobic molecules from the separation column. The amount of contaminant carbon and its 14 C content were determined from two-point measurements of collagen samples of known 14 C content. The amount of foreign carbon due to the isolation process was estimated at 4±1μg and its 14 C content was 0.43±0.01 F 14 C. Radiocarbon values corrected for carbon contamination have only a minor increase in uncertainties. For Holocene samples, this corresponds to an added uncertainty typically smaller than 10 14 Cyears. The developed method can be added to routine AMS measurements without implying significant operational changes and offers a level of measurement uncertainty that is suitable for many archaeological, ecological, environmental, and biological applications. Copyright © 2017. Published by Elsevier B.V.

  14. Determination of 14C age of inorganic and organic carbon in ancient Siberian permafrost

    Science.gov (United States)

    Onstott, T. C.; Liang, R.; Lau, M.; Vishnivetskaya, T. A.; Lloyd, K. G.; Pfiffner, S. M.; Hodgins, G.; Rivkina, E.

    2017-12-01

    Permafrost represents a large reservoir of ancient carbon that could have an important impact on the global carbon budget during climate warming. Due to the low turnover rate of carbon by microorganisms at subzero temperatures, the persistence of ancient carbon in younger permafrost deposits could also pose challenges for radiocarbon dating of permafrost sediment. We utilized Accelerator Mass Spectrometry to determine the 14C age of inorganic carbon, labile and recalcitrant organic carbon in Siberian permafrost sediment sampled at various depths from 2.9 to 5.6m. The fraction of inorganic carbon (CO2) was collected after acidification using phosphoric acid. The labile (younger) and recalcitrant (old) organic carbon in the subsequent residues were collected after combustion at 400 ºC and 800 ºC, respectively. The percentages of inorganic carbon increased from the youngest (2.9m) to the oldest (5.6m), whereas the fractions for organic carbon varied significantly at different depths. The 14C age determined in the inorganic fraction in the top sample (2.9 m) was 21,760 yr BP and gradually increased to 33,900 yr BP in the relative deeper sediment (3.5 and 5.6 m). Surprisingly, the fraction of "younger" carbon liberated at 400 oC was older than the more recalcitrant and presumably older organic carbon liberated at 800 oC in all cases. Moreover, the 14C age of the younger and older organic carbon fractions did not increase with depth as observed in the carbonate fraction. In particular, the 14C age of the organic carbon in the top sample (38,590-41,700 yr BP) was much older than the deeper samples at depth of 3.5m (18,228-20,158 yr BP) and 5.6m (29,040-38,020 yr BP). It should be noticed that the metabolism of ancient carbon in frozen permafrost may vary at different depths due to the different proportion of necromass and metabolically active microbes. Therefore, additional knowledge about the carbon dynamics of permafrost and more investigation would be required to

  15. Dissipation of 14C chlorpyrifos in the rhizosphere of rice

    International Nuclear Information System (INIS)

    Sharungbam, Geeta Devi; Kapadnis, B.P.; Deopurkar, R.L.; Kale, S.P.

    2004-01-01

    The root exudates from the plants contribute to the biodegradation of insecticides. Although, different mechanisms have been proposed, there is no clear elucidation of any mechanism. This study investigates the dissipation of an organophosphorus insecticide, chlorpyrifos in the rhizospheric soil planted with rice plant. Two sets of experimental tanks were maintained with or without plants using soil spiked with 1 mg kg -1 and 10 mg kg -1 of chlorpyrifos. Experiment was conducted for 180 days till the rice plant starts bearing seeds. The 14 C activity decreased rapidly in the rhizospheric soil as compare to the non-rhizospheric soil. The total culturable microflora were higher in the rhizospheric than the non-rhizospheric soil. The plant extract had given few counts indicating some negligible amount of chlorpyrifos uptake. The 14 C activity in the water was disappeared after 30 days. It was observed that very low amount of residue persisted in soil. This studies revealed that the plants play an important role in the dissipation of the chlorpyrifos from the rice flooded rhizospheric soil. (author)

  16. Disposition and metabolism of 14C citrinin in pregnant rats

    International Nuclear Information System (INIS)

    Reddy, R.V.; Hayes, A.W.; Berndt, W.O.

    1982-01-01

    Citrinin is a product of fungal metabolism capable of producing nephrotoxicity. Distribution, excretion and metabolism of ( 14 C) citrinin was studied in pregnant female rats after subcutaneous administration of 35 mg/kg on the 12th day of gestation. Elimination of ( 14 C) citrinin-derived radioactivity from plasma was biphasic. The half-lives of the rapid (α) and slower (β) plases of elimination were 1.95 h and 39.7 h, respectively. Approximately 74% of the radioactivity appeared in the urine in the first 24 h, with only 1.7% and 1.4% in the urine at 48 h 72 h, respectively. Fecal elimination accounted for 9.5%, 4.1% and 7.3% of the total radioactivity at each of these times. At least one metabolite of citrinin was demonstrable with high performance liquid chromatography (HPLC) of plasma extracts. Retention times for the parent compound and metabolite were 270 s and 175 s, respectively. The metabolite was more polar than the parent compound. At least 3 metabolites of citrinin were found in urine of the same rats. Retention times for two metabolites were 140 s and 180 s, with both metabolites more polar than the parent compound. Chromatograms of bile samples suggested at least one metabolite was present with a retention time of 140 s. Chromatograms of uterus extracts indicated the presence of one metabolite with a retention time of 180 s. Chromatograms of fetus extracts indicated that no metabolites of citrinin were present. (author)

  17. A novel stereospecific synthesis of 14C labeled 1-glutamic acid

    International Nuclear Information System (INIS)

    Wurz, R.E.; Kepner, R.E.; Webb, A.D.

    1989-01-01

    A stereospecific synthesis of 4- 14 C-1-glutamic acid was completed in five steps from sodium 2- 14 C-acetate. The morpholine derived enamine of ethyl pyruvate was reacted with ethyl 2- 14 C-bromoacetate to give after hydrolysis diethyl 4- 14 C-2-oxoglutarate. The 2-oxoglutarate was reacted with hydroxylamine hydrochloride to give diethyl 4-14C-2-hydroxyiminoglutarate which was then reduced with a LiAlH4, (-)-N-methylephedrine and 3,5-dimethylphenol mixture to give 4- 14 C-1-glutamic acid. The 4- 14 C-1-glutamic acid was used in investigations into the biosynthesis of gamma-lactones in sherries

  18. Laboratory Intercomparison of Pleistocene Bone Radiocarbon Dating Protocols

    NARCIS (Netherlands)

    Huels, Matthias; van der Plicht, Johannes; Brock, Fiona; Matzerath, Simon; Chivall, David

    2017-01-01

    Since its invention in the late 1940s, radiocarbon (14C) dating has become an important tool for absolute dating. A prerequisite for the acceptance of this method is consistency between, and compatibility of, 14C dates from different laboratories. To meet these requirements, international laboratory

  19. Biokinetics and radiation dosimetry of {sup 14}C-labelled triolein, urea, glycocholic acid and xylose in man. Studies related to nuclear medicine 'breath tests' using accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Gunnarsson, Mikael

    2002-08-01

    {sup 14}C-labelled substances have been used in biomedical research and clinical medicine for over 50 years. Physicians and scientists however, often hesitate to use these substances in patients and volunteers because the radiation dosimetry is unclear. In this work detailed long-term biokinetic and dosimetric estimation have been carried out for four clinically used {sup 14}C-breath tests: {sup 14}C-triolein (examination of fat malabsorption), urea (detection of Helicobacter pylori infection in the stomach), glycocholic acid and xylose (examination of bacterial overgrowth in the small intestine) by using the highly sensitive accelerator mass-spectrometry (AMS) technique. The AMS technique has been used to measure low {sup 14}C concentrations in small samples of exhaled air, urine, faeces and tissue samples and has improved the base for the estimation of the absorbed dose to various organs and tissues and the effective dose to man. The high sensitivity of the AMS system has also made it possible to perform {sup 14}C breath tests on patient groups which were earlier subject for restriction (e.g. small children). In summary, our results show that for adult patients - and in the case of {sup 14}C-urea breath test also for children down to 3 years of age - the dose contributions are comparatively low, both described as organ doses and as effective doses. For adults, the latter is: {sup 14}C-glycocholic acid - 0.4 mSv/MBq, {sup 14}C-triolein - 0.3 mSv/MBq, {sup 14}C-xylose - 0.1 mSv/MBq and {sup 14}C-urea - 0.04 mSv/MBq. Thus, from a radiation protection point of view there is no reason for restrictions in using any of the {sup 14}C-labelled radiopharmaceutical included in this work in the activities normally used (0.07-0.2 MBq for a 70 kg patient)

  20. Synthesis of organic substances labelled with 14C and 35S

    International Nuclear Information System (INIS)

    Pichat, L.

    1958-01-01

    After a brief history of the development of the Section des Molecules marquees of the French Atomic Energy Commission, the author gives an outline of the synthesis of the following labelled compounds: benzene 14 C-6; phenyl-p-fluorophenyl, thienyl-2 β alanines β 14 C; noradrenaline β 14 C (arterenol β 14 C), dotriacontane 14 C-16-17, aminoethane sulfinic acid (hypotaurine 35 S). (author) [fr

  1. Preparation and HPLC isolation of L-[U-14C]tryptophan from enzyme hydrolysate labelled with 14C

    International Nuclear Information System (INIS)

    Novak, J.; Tintera, S.; Hromadkova, B.

    1990-01-01

    Tryptophan was obtained from biomass of the blue-green alga Synechococcus elongatus cultivated under 14 CO 2 . After partial purification, the protein fraction was subjected to enzymatic hydrolysis using pronase. Semipreparative isolation of L-[U- 14 C]tryptophan was accomplished on a HPLC column of Separon S Hema 1000 CM, 2% ethanol were added to the eluent, and a precolumn packed with the basic anion exchanger Spheron 1000 DEAE was used. Always after the passage of L-[U- 14 C]tryptophan, the precolumn was decoupled. The substance was collected in 96% ethanol. After removing the solvent by vacuum evaporation, the sample was analyzed on a column packed with Separon SIX C 18 in the eluent of 0.1M-NaH 2 PO 4 , 2% methanol. When the desired radiochemical purity was not attained, the sample was purified on Separon SIX C 18 using 2% methanol. The final radiochemical purity achieved by using this method is 98%. (P.A.). 5 figs., 2 tabs., 4 refs

  2. Distribution of 14C in soil and rice plants following application of 14C - parathion to soil

    International Nuclear Information System (INIS)

    Andrea, M.M. de; Ruegg, E.F.

    1983-01-01

    Amount of residues of 14 C-parathion in soil rice plants after application of the insecticide to soil were determined in four systems studied during five weeks: pots of soil with and without plants and open or enclosed by a transparent cover. Measurements of amounts volatilized and 14 CO 2 evolution from the pesticide were made in closed system without plants. The bound residues in soil and plants were also determined. Results indicated that parathion half life in a Gley Humic soil was about two weeks. Very little radiocarbon was taken up by rice plants; of this, more was found in shoots of plants enclosed, probably by collection of the volatilized material by plants. About 6% and 4% of the 14 C-parathion were found as volatilized material and 14 CO 2 , respectively after five weeks. Bound residues varied very little and reached a maximum of 22% in soil and in plants amounted to less than 2% at the final of the experiment. (Author) [pt

  3. Radiocarbon dating for tree rings of dendro-chronologically dated Japan cedars buried in the paddy field at Fukui

    International Nuclear Information System (INIS)

    Shibata, S.; Kawano, E.; Kimura, K.; Mine, T.; Harada, M.

    1999-01-01

    14 C dating of 6 Japan cedars having the relative growing ages were made. On the basis of correlation analysis of our data to a 14 C age data set, INTCAL of CALIB (Stuiver), the growing ages of these Japan cedars were estimated (BC 1090-2375). The atmospheric 14 C concentration (Δ 14 C) at their growing ages were obtained from the 14 C age data. The variation of Δ 14 C shows basically the same pattern with that of Europe or America (r=0.783). (author)

  4. Mobility and degradation of 14C-trifluralin in soil

    International Nuclear Information System (INIS)

    Zheng Lin; Wang Fujun

    1993-01-01

    Under laboratory condition, the adsorption, mobility and degradation of 14 C-trifluralin in soil were studied by using radioactive isotopic tracer. The results show that the adsorption of trifluralin in soil is quite strong. The rates of adsorption in soil are 73.89 ∼ 90.66%. The adsorption is significantly affected by the organic matter content of soil. It leaches rather low in Grassy-marsh land black soil containing plentiful organic matter and higher clay content, but quite higher in sand, and is more easily to move down. Under anaerobic condition, degradation of trifluralin in soil is faster. It is derogated by 60.2 ∼ 60.4% in soil extractive state within 30 days, and by 90.0 ∼ 94.7% within 60 days. Its main metabolites are the compounds with R f 0.06, 0.15 and 0.42 respectively

  5. Decomposition of 14C - malathion in three Brazilian soil samples

    International Nuclear Information System (INIS)

    Helene, C.G.; Ruegg, E.F.

    1982-01-01

    The degradation of 14 C-malathion in soil was examined using gas chromatography and radiotracer techniques. About half of the malathion added was degraded within a day in soil from three regions of Brazil. Almost all the radiolabelled material extracted from the Red Latosol (Londrina, PR) was malathion, but metabolites were extracted from the 'Sandy' cerrado soil (Planaltina, DF) and Dark-Red Latosol (Passo Fundo, RS). The proportion of metabolites in the extracts increased until most of the malathion was degraded, after four days. Radiocarbon dioxide was liberated from all three soils at similar rates. When about half of the label had been recovered as carbon dioxide after eight weeks, the rate of evolution diminished. (Author) [pt

  6. Synthesis of CH3CH2Br - 14C-1

    International Nuclear Information System (INIS)

    Wolff, R.E.; Pichat, L.

    1958-01-01

    The synthesis of ethyl bromide labelled with 14 C, starting from ethanol, has already been studied: 1- by TOLBERT, CHRISTENSON, NAI-HSUAN and SAH; 2- by SIXMA and HENDRIKS. After various blank tests of these two methods, we have finally obtained the best yields by treating the ethanol with a mixture of 40 per cent hydrobromic acid and concentrated sulphuric acid, in the apparatus normally used in the laboratory for the synthesis of CH 3 I slightly modified, so that the current of nitrogen carrying ethyl bromide and hydrobromic acid passes through a sintered glass disc before being bubbled through a solution of NaOH. We describe here the practical process used for the blank test which gave the best yield (91 per cent) and the active synthesis. (author) [fr

  7. Fate of [14C]-zineb on lettuce plants

    International Nuclear Information System (INIS)

    Vonk, J.W.

    1976-01-01

    [1,2- 14 C]-zinc ethylenebisdithiocarbamate (zineb) was prepared and applied in droplets to leaves of lettuce plants. In aqueous suspension zineb decomposes mainly into ethylenethiourea (ETU) and 5,6-dihydro-3H-imidazo[2,1-C]-1,2,4-dithiazole-3-thione (DIDT). Lettuce plants were harvested 0,1,3,7,14 and 21 days after treatment and analysed. A high proportion of radioactivity remained on the surface of the plant and could be washed off. The following identified products were present: unchanged zineb, ETU, DIDT, 2-imidazoline and ethyleneurea. The ETU residue disappeared within 7 days, while 2-imidazoline and ethyleneurea were formed gradually. Radioactivity inside the plant consisted mostly of ethyleneurea: no ETU was present. (author)

  8. 14C-Profenofos Residues in Milk and Milk Products

    International Nuclear Information System (INIS)

    Fakhr, I.M.I.; Afifi, L.M.; Fouzy, A.S.M.; Hegazi, B.

    1999-01-01

    Treatment of lactating goats with only one dose of 14 C-ethoxy profenofos (17.9 mg/Kg) in gelatin capsules and then feeding normally, resulted in the presence of 0.5% of the radioactive insecticide residues in the milk collected through the fourteen successive days. The highest activity level was depicted at the first day and almost disappeared after two weeks. After processing, the analysis of milk products revealed difference in radioactive residue level according to the nature of the product and increased in the order: whey< skim < yoghurt < pasteurized milk < cheese< cream. TLC analysis of milk and milk products revealed the absence of the parent compound and the presence of 4 major metabolites, which were identified by co-chromatography with authentic compounds

  9. Metabolism of 14C-lindane in flooded alluvial soil

    International Nuclear Information System (INIS)

    Siddaramappa, R.; Sethunathan, N.

    1975-01-01

    The effect of rice straw on the persistence of uniformly ring labelled 14 C-lindane in an alluvial soil was investigated under flooded conditions. The residues in the soil were extracted with chloroform-diethyl ether and the radioactivity was measured by liquid scintillation. The radioactivity in the solvent phase decreased more rapidly in amended soil than in unamended soil. Radioautograph of thin layer chromatograms of solvent phase indicated that lindane was readily converted to a breakdown product in both amended and unamended soils. This breakdown product was also formed in both autoclaved and nonautoclaved soils. Rice straw amendment enhanced further decomposition of lindane and its breakdown product. Heat treatment retarded further decomposition of lindane and its breakdown product whereas they were rapidly decomposed in nonautoclaved soil. These studies indicated that in flooded alluvial soil tested, lindane was initially decomposed by a chemical reaction and soil microorganisms appeared to attack the products of the chemical reaction. (author)

  10. The degradation of [14C] parathion in two Brazilian soils

    International Nuclear Information System (INIS)

    Andrea, M.M. de; Lord, K.A.; Bromilow, R.H.; Ruegg, E.F.

    1980-01-01

    Loss of [ 14 C] parathion from two Brazilian soils was studied by measuring the parathion which could be extracted by a mixture of hexane and propanol and the 14 CO 2 evolved. Recovery of unchanged parathion decreased faster in the soil richer in organic matter (soil 1) from which more radiocarbon was evolved as CO 2 than from the soil poorerin organic matter (soil 2). Evolution of CO 2 from soil 1 decreased rapidly when the soil dried out but little effect of moisture content was observed in soil 2. Radiocarbon remaining in the soils was assayed by combustion after 234 days and the total recovered in soil 1 was 95.6% and, in soil 2,78.7%, sufficient to give almost complete recovery from both soils. (Author) [pt

  11. Asymmetric [14C]albumin transport across bullfrog alveolar epithelium

    International Nuclear Information System (INIS)

    Kim, K.J.; LeBon, T.R.; Shinbane, J.S.; Crandall, E.D.

    1985-01-01

    Bullfrog lungs were prepared as planar sheets and bathed with Ringer solution in Ussing chambers. In the presence of a constant electrical gradient (20, 0, or -20 mV) across the tissue, 14 C-labeled bovine serum albumin or inulin was instilled into the upstream reservoir and the rate of appearance of the tracer in the downstream reservoir was monitored. Two lungs from the same animal were used to determine any directional difference in tracer fluxes. An apparent permeability coefficient was estimated from a relationship between normalized downstream radioactivities and time. Results showed that the apparent permeability of albumin in the alveolar to pleural direction across the alveolar epithelial barrier is 2.3 X 10(-7) cm/s, significantly greater (P less than 0.0005) than that in the pleural to alveolar direction (5.3 X 10(-8) cm/s) when the tissue was short circuited. Permeability of inulin, on the other hand, did not show any directional dependence and averaged 3.1 X 10(-8) cm/s in both directions. There was no effect on radiotracer fluxes permeabilities of different electrical gradients across the tissue. Gel electrophoretograms and corresponding radiochromatograms suggest that the large and asymmetric isotope fluxes are not primarily due to digestion or degradation of labeled molecules. Inulin appears to traverse the alveolar epithelial barrier by simple diffusion through hydrated paracellular pathways. On the other hand, [ 14 C]albumin crosses the alveolar epithelium more rapidly than would be expected by simple diffusion. These asymmetric and large tracer fluxes suggest that a specialized mechanism is present in alveolar epithelium that may be capable of helping to remove albumin from the alveolar space

  12. Removal of 14C from nitrogen annulus gas

    International Nuclear Information System (INIS)

    Cheh, C.H.

    1985-01-01

    A dry, ambient temperature process using Ca(OH) 2 as the sorbent to remove 14 CO 2 from moderator cover gas was further developed to remove 14 C from the extremely dry nitrogen annulus gas. Thermal gravimetric analysis was carried out to study the thermal stability of Ca(OH) 2 and the CO 2 -Ca(OH) 2 reaction at elevated temperatures under extremely low humidity conditions. Results shows that to achieve high utilization and avoid decomposition of Ca(OH) 2 , humidification of the annulus gas was necessary at high or low temperatures. Results of the bench scale (1-10 L/min) oxidizer study showed that, with 0.5% Pd or alumina as the catalyst, it was possible to achieve complete oxidation of CO and over 80% oxidation of CH 4 with 1% hydrogen in the nitrogen. The gas superficial velocity should be less than or equal to30 cm/s and the residence time greater than or equal to0.5 s. A pilot scale (up to 160 L/min) system including a catalytic oxidizer, a humidifier/demister, a Ca(OH) 2 reactor, a condenser/demister and regenerable molecular sieve dryers, was assembled and tested with simulated nitrogen annulus gas. Results showed that complete oxidation of the CO and 60-100% oxidation of the CH 4 with 0.5% H 2 in the simulated gas were achieved in the pilot plant. The CO 2 concentration was reduced from 30-60 μL/L at the inlet of the Ca(OH) 2 reactor to 1 μL/L or less at the outlet. After modifications of the dryer to overcome the problems encountered, the simulated annulus gas was dried to 0 C dew point before recirculation. Equipment specifications and operating conditions of a 14 C removal system for nitrogen annulus gas are summarized

  13. Longevity and growth of Acacia tortilis; insights from 14C content and anatomy of wood.

    Science.gov (United States)

    Andersen, Gidske L; Krzywinski, Knut

    2007-06-15

    Acacia tortilis is a keystone species across arid ecosystems in Africa and the Middle East. Yet, its life-history, longevity and growth are poorly known, and consequently ongoing changes in tree populations cannot be managed in an appropriate manner. In other arid areas parenchymatic bands marking growth zones in the wood have made dendrochronological studies possible. The possibilities for using pre- and post-bomb 14C content in wood samples along with the presence of narrow marginal parenchymatic bands in the wood is therefore tested to gain further insight into the age, growth and growth conditions of A. tortilis in the hyper-arid Eastern Desert of Egypt. Based on age scenarios and the Gompertz growth equation, the age of trees studied seems to be from 200 up to 650 years. Annual radial growth estimated from calibrated dates based on the post-bomb 14C content of samples is up to 2.4 mm, but varies both spatially and temporally. Parenchymatic bands are not formed regularly. The correlation in band pattern among trees is poor, both among and within sites. The post-bomb 14C content of A. tortilis wood gives valuable information on tree growth and is required to assess the age scenario approach applied here. This approach indicates high longevities and slow growth of trees. Special management measures should therefore be taken at sites where the trend in tree population size is negative. The possibilities for dendrochronological studies based on A. tortilis from the Eastern Desert are poor. However, marginal parenchymatic bands can give insight into fine scale variation in growth conditions and the past management of trees.

  14. Longevity and growth of Acacia tortilis; insights from 14C content and anatomy of wood

    Directory of Open Access Journals (Sweden)

    Krzywinski Knut

    2007-06-01

    Full Text Available Abstract Background Acacia tortilis is a keystone species across arid ecosystems in Africa and the Middle East. Yet, its life-history, longevity and growth are poorly known, and consequently ongoing changes in tree populations cannot be managed in an appropriate manner. In other arid areas parenchymatic bands marking growth zones in the wood have made dendrochronological studies possible. The possibilities for using pre- and post-bomb 14C content in wood samples along with the presence of narrow marginal parenchymatic bands in the wood is therefore tested to gain further insight into the age, growth and growth conditions of A. tortilis in the hyper-arid Eastern Desert of Egypt. Results Based on age scenarios and the Gompertz growth equation, the age of trees studied seems to be from 200 up to 650 years. Annual radial growth estimated from calibrated dates based on the post-bomb 14C content of samples is up to 2.4 mm, but varies both spatially and temporally. Parenchymatic bands are not formed regularly. The correlation in band pattern among trees is poor, both among and within sites. Conclusion The post-bomb 14C content of A. tortilis wood gives valuable information on tree growth and is required to assess the age scenario approach applied here. This approach indicates high longevities and slow growth of trees. Special management measures should therefore be taken at sites where the trend in tree population size is negative. The possibilities for dendrochronological studies based on A. tortilis from the Eastern Desert are poor. However, marginal parenchymatic bands can give insight into fine scale variation in growth conditions and the past management of trees.

  15. Transfer of {sup 14}C to prenatal and neonatal rats from their mothers exposed to {sup 14}C compounds by ingestion

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, H.; Fuma, S.; Miyamoto, K.; Kuroda, N.; Inaba, J

    2003-07-01

    The transfer of {sup 14}C through placenta or milk was investigated and the radiation dose to fetal and newborn rats was estimated. Female rats at gestational stages or after delivery were exposed to {sup 14}C in the form of sodium bicarbonate, thymidine and lysine by a single ingestion. Radioactivity in maternal tissues and conceptuses (placenta, fetal membrane and fetus) and in the newborn was determined at various times after ingestion. After exposure to these {sup 14}C compounds, there was no significant difference between the {sup 14}C concentration in the fetus and that in the maternal tissues, suggesting that the placenta has no effect in preventing or accelerating the placental transfer of {sup 14}C. The concentration and content of {sup 14}C in the fetus and newborn were, however, dependent on the chemical form of {sup 14}C and on the prenatal or neonatal stage at the time of ingestion. The result of the dose estimation showed that {sup 14}C-lysine gave significantly higher prenatal and neonatal doses than {sup 14}C-sodium bicarbonate or {sup 14}C-thymidine. (author)

  16. New radiocarbon dates for Milu (Elaphurus davidianus) sub-fossils from southeast China

    Energy Technology Data Exchange (ETDEWEB)

    Ding, X.F. [State Key Laboratory of Nuclear Physics and Technology and Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing 100871 (China); Shen, C.D., E-mail: cdshen@gig.ac.cn [State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 510640 Guangzhou (China); Ding, P.; Yi, W.X. [State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 510640 Guangzhou (China); Fu, D.P.; Liu, K.X. [State Key Laboratory of Nuclear Physics and Technology and Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing 100871 (China)

    2013-01-15

    Milu (Elaphurus davidianus, Pere David's deer) is one of the few species of large mammals that became extinct in the wild, but survived domestically. A good understanding of expansion and habitat is required if the reintroduction of Milu into the wild is to be implemented. Among the widely reported findings of Milu sub-fossils, only a small fraction have been dated. Here we report new AMS radiocarbon dates on Milu sub-fossil samples unearthed from two sites at Qingdun, Jiangsu and Fujiashan, Zhejiang in southeast China. These AMS {sup 14}C ages of Milu sub-fossils provide new evidence for the presence of Milu expansion in the lower reaches of the Yangtze River during the Holocene Optimum interval from 5000 yr BC to 3000 yr BC. These new ages also have important implications for the reconstruction of the paleoclimate and paleogeography during the Neolithic Period in southeast China.

  17. Method for evaluating the potential of 14C labeled plant polyphenols to cross the blood-brain barrier using accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Janle, Elsa M.; Lila, Mary Ann; Grannan, Michael; Wood, Lauren; Higgins, Aine; Yousef, Gad G.; Rogers, Randy B.; Kim, Helen; Jackson, George S.; Weaver, Connie M.

    2010-01-01

    Bioactive compounds in botanicals may be beneficial in preventing age-related neurodegenerative diseases, but for many compounds conventional methods may be inadequate to detect if these compounds cross the blood-brain barrier or to track the pharmacokinetics in the brain. By combining a number of unique technologies it has been possible to utilize the power of AMS to study the pharmacokinetics of bioactive compounds in the brain at very low concentrations. 14 C labeled compounds can be biosynthesized by plant cell suspension cultures co-incubated with radioisotopically-labeled sucrose and isolated and separated into a series of bioactive fractions. To study the pharmacokinetics and tissue distribution of 14 C labeled plant polyphenols, rats were implanted with jugular catheters, subcutaneous ultrafiltration probes and brain microdialysis probes. Labeled fractions were dosed orally. Interstitial fluid (ISF) and brain microdialysate samples were taken in tandem with blood samples. It was often possible to determine 14 C in blood and ISF with a β-counter. However, brain microdialysate samples 14 C levels on the order of 10 7 atoms/sample required AMS technology. The Brain Microdialysate AUC /Serum AUC ranged from .021- to .029, with the higher values for the glycoside fractions. By using AMS in combination with traditional methods, it is possible to study uptake by blood, distribution to ISF and determine the amount of a dose which can reach the brain and follow the pharmacokinetics in the brain.

  18. Authentication of Chinese vintage liquors using bomb-pulse 14C

    Science.gov (United States)

    Cheng, Peng; Zhou, Weijian; Burr, G. S.; Fu, Yunchong; Fan, Yukun; Wu, Shugang

    2016-12-01

    The older a bottle of Chinese vintage liquor is, the higher the price it commands. Driven by the potential for higher profits, some newly-founded distilleries openly sell liquor whose storage ages are exaggerated. In China, the market for vintage liquor has become fraught with uncertainty and a pressing need has arisen to establish an effective method to authenticate the age of vintage liquors. A radiocarbon (14C) dating method is described here that can verify cellar-stored years of Chinese liquors distilled within the last fifty years. Two different flavored Chinese liquors produced in “the golden triangular region” in the Upper Yangtze River region in southwest China, with known cellar-stored years, were analyzed to benchmark the technique. Strong flavored liquors are found to be consistent with local atmospheric Δ14C values. A small offset of 2-3 years between predicted vintage years of soy-sauce flavored liquors and strong flavored liquors is found to be associated with the fermentation cycle of certain varieties. The technique can measure cellar-stored years of a wide range of liquors including those with fundamentally different aromas. This demonstrates the strength of our method in identifying suspect Chinese vintage liquors.

  19. A rapid microwave induced synthesis of [carboxyl-14C]-nicotinic acid (vitamin B3) and [carbonyl-14C]-nicotinamide using K14CN

    International Nuclear Information System (INIS)

    Ravi, S.; Mathew, K.M.; Sivaprasad, N.

    2008-01-01

    Microwave assisted direct aromatic substitution of 3-bromopyridine with K 14 CN as the cyanide source and catalytic amount of tetrabutylammonium bromide afforded [3- 14 C]-cyanopyridine 3 in 90% yield. Microwave assisted hydrolysis of 3 with a mixture of concentrated hydrochloric acid and propionic acid afforded [carboxyl- 14 C]-nicotinic acid in 95% yield whereas microwave assisted hydrolysis of 3 with a mixture of concentrated sulfuric acid and propionic acid afforded [carbonyl- 14 C]-nicotinamide in 85% yield. (author)

  20. Comparison of 14C and U-Th ages of two Holocene phreatic overgrowths on speleothems from Mallorca (Western Mediterranean: Environmental implications

    Directory of Open Access Journals (Sweden)

    Tuccimei Paola

    2011-01-01

    Full Text Available This investigation reports on the comparison between ICP-MS U-Th and AMS 14C ages of Phreatic Overgrowths on Speleothems (POS from two different caves on the island of Mallorca (Spain. These speleothem encrustations form at the water table of coastal caves in a low-amplitude tide-controlled microenvironment and are used to reconstruct past sea level changes. The aim of this study is to evaluate if this particular type of speleothem is datable using 14C method and to investigate possible problems connected with the incorporation of dead carbon inherited from the dissolution of 14C-free limestone. The results show that 14C ages are strongly site dependent and appear related to local residence time of water infiltration through the soil and epikarst. When short transit time and limited interaction with soil and bedrock, as in Cova de Cala Varques A, the so-called “reservoir” effect is negligible and 14C and U-Th ages corresponds within the error range. When the residence time is longer, as in Cova des Pas de Vallgornera, 14C ages are steadily 2,300-2,400 years older than the U-Th data, as shown by the mean value (25% of estimated percent dead carbon proportions and by higher and better correlated contents of major and trace elements in the vadose support of this speleothem encrustation. The potential use of this multi-method approach to paleoenvironmental studies is also suggested.

  1. Status report of AMS sample preparation laboratory at GADAM Centre, Gliwice, Poland

    Energy Technology Data Exchange (ETDEWEB)

    Piotrowska, N., E-mail: natalia.piotrowska@polsl.pl [GADAM Centre of Excellence, Department of Radioisotopes, Institute of Physics, Silesian University of Technology, Gliwice (Poland)

    2013-01-15

    The laboratory for {sup 14}C AMS sample preparation in the Gliwice Radiocarbon Laboratory has gradually evolved since its start in 1999 to cater for an increase in volume and variety of radiocarbon dating samples. To date, nearly 2000 graphite targets have been produced from materials such as plant macrofossils, charcoal, peat, bones, shells and wood. The equipment comprises a station for chemical preparation and high vacuum lines for production, purification and graphitization of sample carbon dioxide. The present capacity allows preparation of up to 400 targets annually for the needs of scientific projects and external orders for radiocarbon dating continuously received by the GADAM Centre of Excellence. The laboratory's sample preparation protocols and recent improvements are described and its performance during the 10 years of activity is discussed in terms of parameters obtained from reference materials prepared in this laboratory and demonstrated with a few science applications.

  2. Changes in the level of [14C]indole-3-acetic acid and [14C]indoleacetylaspartic acid during root formation in mung bean cuttings

    International Nuclear Information System (INIS)

    Norcini, J.G.; Heuser, C.W.

    1988-01-01

    Changes in the levels of [ 14 C]indole-3-acetic acid (IAA) and [ 14 C]indoleacetylaspartic acid (IAAsp) were examined during adventitious root formation in mung bean (Vigna radiata [L.] R. Wilcz. Berken) stem cuttings. IAAsp was identified by GC-MS as the primary conjugate in IAA-treated cuttings. During root formation in IAA-treated cuttings, the level of [ 14 C]IAAsp increased rapidly the first day and then declined; [ 14 C]IAA was rapidly metabolized and not detected after 12 hours

  3. Effect of endomycorrhizae on the bioavailability of bound 14C residues to onion plants from an organic soil treated with [14C]fonofos

    International Nuclear Information System (INIS)

    Nelson, S.D.; Khan, S.U.

    1990-01-01

    Uptake of bound 14 C residues from an organic soil treated with radiolabeled fonofos (O-ethyl S-phenyl ethylphosphonodithioate) by selected Glomus endomycorrhiza and onion roots was studied. The hyphae of endomycorrhizal associations were capable of removing 14 C residues from the soil and transporting them to onion plants. Bioavailability of soil-bound 14 C residues, as measured by 14 C residue content in onion, was increased 32 and 40% over that of nonmycorrhizal plants by hyphae of Glomus intraradices and Glomus vesiculiferium, respectively. The data suggest that under field conditions endomycorrhizal infection may greatly increase the bioavailability of soil-bound pesticide residues to plants

  4. Comparative in vitro metabolism of 1-14C-oleic acid and 1-14C-erucic acid in liver, heart and skeletal muscles of rats

    International Nuclear Information System (INIS)

    Bhatia, I.S.; Sharma, A.K.; Ahuja, S.P.

    1978-01-01

    In vitro oxidation of 14 C-oleic and 1- 14 C-erucic acid and their incorporation into lipids by liver, heart and skeletal muscles from female albino rats were studied. These tissues were obtained from rats maintained for 120 days on low fat diet or diets containing 15% mustard oil or 15% groundnut oil. In all these tissues from rats on different types of diets, the oxidation of 1- 14 C-erucic acid was lower than that 1- 14 C-oleic acid. There was little accumulation of lipids in heart after 120 days of feeding mustard oil. Oxidation of 1- 14 C-erucic acid was enhanced in liver, heart and skeletal muscles of rats conditioned to the mustard oil diet supplying erucic acid. Oxidation of erucic acid was maximum in liver and least in heart, whereas there were no differences in the oxidation of 1- 14 C-oleic acid in these tissues. Incorporation of 1- 14 C-oleic acid into triglycerides and phospholipids was not affected by the type of diet or tissues Incorporation of 1- 14 C-erucic acid was mainly into triglycerides of heart and skeletal muscles of rats not accustomed to mustard oil diet whereas these tissues from rats accustomed to mustard oil diets incorporated 1- 14 C-erucic acid both into the triglycerides and phospholipids. (author)

  5. Biomarker and carbon isotope constraints (δ13C, Δ14C) on sources and cycling of particulate organic matter discharged by large Siberian rivers draining permafrost areas

    International Nuclear Information System (INIS)

    Winterfeld, Maria

    2014-08-01

    biomarker composition, diagenetic alteration, and radiocarbon age. The second part of this thesis investigates past permafrost dynamics and the possible permafrost/wetland climate feedback during the last deglaciation and Early Holocene. The Amur hinterland in East Siberia was most likely characterized by extensive permafrost during the last glacial maximum and is today permafrost-free with the exception of small areas in the northern reaches of the catchment. The organic matter flux of the Amur River into its receiving basin, the Okhotsk Sea, was reconstructed for the last 16,000 years in a high-resolution AMS 14 C-dated sediment core from the Sakhalin continental margin, based on organic geochemical multi-proxy data and compound-specific radiocarbon dating of n-alkanoic acids. Within the deglacial discharge maximum of organic matter to the Okhotsk Sea, two peaks of organic matter release episodes; the first occurring during the Bolling-Allerod warm phase, and the second, larger one after Termination Ib in the earliest Preboreal could be identified. The results highlight the sensitivity of the Amur drainage basin carbon reservoir to rapid deglacial temperature and precipitation changes. It is hypothesized that large amounts of carbon were activated upon deglacial permafrost thawing within this southernmost Siberian large catchment and quickly transferred to the oceanic carbon reservoir via riverine freshwater transport into the Okhotsk Sea and the North Pacific.

  6. Dating of cremated bones

    OpenAIRE

    Lanting, JN; Aerts-Bijma, AT; van der Plicht, J; Boaretto, E.; Carmi, I.

    2001-01-01

    When dating unburnt bone, bone collagen, the organic fraction of the bone, is used. Collagen does not survive the heat of the cremation pyre, so dating of cremated bone has been considered impossible. Structural carbonate in the mineral fraction of the bone, however, survives the cremation process. We developed a method of dating cremated bone by accelerator mass spectrometry (AMS), using this carbonate fraction. Here we present results for a variety of prehistoric sites and ages, showing a r...

  7. The development of high precision 14C measurement and its application to archaeological time-scale problems

    International Nuclear Information System (INIS)

    Pearson, G.W.

    1983-01-01

    High precision calibration curve of some 6000 years has been constructed from the measurement of contiguous 20 year samples of dendrochronologically dated Irish oak. 14 C evidence was presented using a 'wiggle' matching technique which supported the dendrochronological fixing of the BC period Irish oak chronology. Two archaeological samples were 'wiggle matched' to give a calendar age within a range of 25 years and proved that this technique is as precise as dendrochronological dating and is potentially as useful for a much wider range of samples and growth periods. (author)

  8. Stability of the 14 C-Radiolabelled insecticide guthion

    International Nuclear Information System (INIS)

    Fakhr, I.M.I.; Shaheen, F.A.; Hazzaa, N.I.; Hamdy, N.A.

    1993-01-01

    Under variable conditions simulating those of the agricultural practice, the effects of temperature and PH variations on the stability of 14 C-guthion have been studied. It was found that the insecticide is fairly stable in the acid medium and the half-life of the compound reached 230 days at 25 degree C and declined to about 7 days at 54 degree C, but in the alkaline medium, the degradation rate clearly increased as the PH increased and the half-life reached 24 hours in PH 11 at 25 degree C. In the neutral medium, the half-life was about eight days at 25 degree C while at 54 degree C, it was three days. The insecticide decomposed rapidly as the temperature was raised and the rate was much increased by the combined increase in heat and alkalinity. Some of the degradation products were identified as: O,O-dimethylthio- and di thiophosphoric acid, 4-O x O-3,4-dihydro, 1,2,3-benzo triazine and its hydroxymethyl derivative. 2 figs., 1 tab

  9. Adsorption and desorption of 14C-chlorsulfuron in soils

    International Nuclear Information System (INIS)

    Chen Zuyi; Cheng Wei; Mi Chunyun

    1995-01-01

    The adsorption and desorption of the 4 concentrations of 14 C-chlorsulfuron in 10 soils were studied. As a result the soils had weak adsorptions of chlorsulfuron and the adsorptions varied with different type of soils tested. Adsorption rate of paddy soil (infant red earth) from Hunan and latosol red earth from Hainan was 3%∼4%; Yellow-brown earth from Nanjing and red earth from Jiangxi was 6%∼9%; black soil from Jilin, paddy soil (infant red earth) from Jiangxi and red earth from Anhui was 10%∼14%; Albic bleached soil from Jilin and yellow fluvo-aquatic soil from Jiangsu was 19%∼23%. pH value had an influence on the adsorption and organic matter had not obvious influence on the adsorption. Chlorsulfuron absorbed in soil could be desorbed through water. The relation between the adsorption and desorption was negative. The weak adsorption in soil shows that chlorsulfuron is active movable and diffusible and likely to pollute the ecological environment

  10. Biodegradation of14 C-lindane by some soil fungi

    International Nuclear Information System (INIS)

    Attaby, H.S.H.; Adam, Y.M.

    1991-01-01

    In a culture medium incorporated with 14 C-labelled lindane, the 3 soil fungi helminthosporium sp., alternaria brassicola, and verticillium agaricinum were incubated for 10 days. Most of the recovered radioactivity was found to be maintained mainly in the medium of helminthosporium and alternaria but in case of verticillium the majority was associated with the mat. The 3 fungal species showed degradation capacity of 6.1, 5.1 and 3.2% of the total recovered radioactivity radioactivity as hydrolytic products. TLC chromatographic analysis of chloroform fractions revealed the presence of only unchanged lindane either in medium of mat. The aqueous fractions of the 3 fungal species, demonstrated three degraded products (unknown ι,π and tri) having Rf values of 0.40 - 0.47, 0.66 - 0.73, and 0.87 in addition to a polar compound (Rf = 0.07) with the major radioactivity. A certain percentage of radiocarbon 6.7, 5.7 and 30.3% of the mats of helminthosporium, alternria and verticillium, respectively.2 tab

  11. Depletion of [14C]clorsulon in cows' milk

    International Nuclear Information System (INIS)

    Chiu, S.H.L.; Baylis, F.P.; Taub, R.; Green, M.; Halley, B.A.; Bodden, R.M.

    1989-01-01

    Radioactive residue levels were determined in milk and plasma of Holstein cows dosed once with an oral suspension of 14 C-labeled clorsulon at 7 mg/kg of body weight. Average milk residue levels decreased from 0.54 ppm at 0.9 day postdose to 0.004 ppm at 6.9 days postdose with a half-life of 0.81 day. The drug residue was isolated by a batch adsorption method on an affinity agarose gel of carbonic anhydrase-Sepharose 4B and analyzed by HPCL-reverse isotope dilution assay (RIDA). This novel method greatly simplified the extraction of drug residue from milk and provided pure drug residue isolates. RIDA results of the isolates indicated that the unchanged drug was the major residue component in milk at 0-4 days postdose accounting for 56-99% of the total radioactive residue. Depletion half-life of the parent drug was 0.82 day, in close agreement with that of the total residue in milk. About 0.7% of the dose was recovered in the milk during the 6.9-day period

  12. Metabolism of 14C-diazinon by gypsy moth larvae

    International Nuclear Information System (INIS)

    Ahmad, S.; Forgashi, A.J.

    1975-01-01

    The metabolic fate of diazinon in larvae of Porthetria dispar (L.) was determined using 14 C-ring-labeled material. Following a 4-h ingestion period, 28.7 percent of the total recovered activity was present as diazinon in the larvae and 0.2 percent in the feces at 1 hr; by 12 h these amounts had changed to 1.4 and 15.4 percent, respectively. The major transformation products were 2,isopropyl-4-methyl-6-pyrimidinol greater than diazoxon greater than hydroxydiazinon greater than 2-(2'-hydroxy-2'-propyl)-4-methyl-6-pyrimidinol. Small amounts of 5 additional products were detected but were not identified. Metabolism of topically applied diazinon was the same qualitatively as that of ingested diazinon, based on a comparison of chloroform-extractable metabolites, although quantitative differences were evident. The synergists 2,6-dichlorobenzyl-2-propynyl ether (GA4-282) and piperonyl butoxide (PB) altered the metabolism of diazinon (both ingested and topical doses) by apparently similar actions, resulting in a reduction in the formation of 2-isopropyl-4-methyl-6-pyrimidinol, hydroxydiazinon, and 2-(2'-hydroxy-2'-propyl)-4-methyl-6-pyrimidinol

  13. Making a date with radiocarbon

    International Nuclear Information System (INIS)

    Gribbin, J.

    1979-01-01

    The use of 14 C dating techniques for samples of organic materials up to 50,000 years old is discussed with especial reference to adjustment necessary to take account of both the most recent figure for the 14 C half-life and also the natural fluctuations in the production of 14 C over 50,000 years. Methods of detection and the accuracy of the measurements are considered. It is hoped that future developments including both the possibility of counting 14 C ions directly using an accelerator as a mass spectrometer, and also the use of laser enrichment techniques will not only push back the radiocarbon calendar to 100,000 years but will also allow the use of much smaller samples than before. (U.K.)

  14. Defective [U-14 C] palmitic acid oxidation in Duchenne muscular dystrophy

    International Nuclear Information System (INIS)

    Carroll, J.E.; Norris, B.J.; Brooke, M.H.

    1985-01-01

    Compared with normal skeletal muscle, muscle from patients with Duchenne dystrophy had decreased [U-14 C] palmitic acid oxidation. [1-14 C] palmitic acid oxidation was normal. These results may indicate a defect in intramitochondrial fatty acid oxidation

  15. Defective (U-14 C) palmitic acid oxidation in Duchenne muscular dystrophy

    Energy Technology Data Exchange (ETDEWEB)

    Carroll, J.E.; Norris, B.J.; Brooke, M.H.

    1985-01-01

    Compared with normal skeletal muscle, muscle from patients with Duchenne dystrophy had decreased (U-14 C) palmitic acid oxidation. (1-14 C) palmitic acid oxidation was normal. These results may indicate a defect in intramitochondrial fatty acid oxidation.

  16. Urvina Bay, Galapagos Coral Radiocarbon (delta 14C) Data for 1956 to 1982

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Urvina Bay coral radiocarbon (14C) timeseries. (90 deg W, 0.5 deg S) Coral radiocarbon (Delta-14C) on untreated, low-speed drilled samples. Precision is +/- 4 per...

  17. Synthesis of glycolic acid-1-14C of high specific activity

    International Nuclear Information System (INIS)

    Ramamurthy, T.V.; Viswanathan, K.V.

    1987-01-01

    A simple procedure is described which efficiently converts traces of 14 C labelled cyanide present as a dilute solution into glycolic acid-1- 14 C with more than 85% radiochemical recovery and of high specific activity. (author)

  18. Synthesis of uniformly labelled organic compounds by polymerization of 14C ethylene

    International Nuclear Information System (INIS)

    Dauphin, J.-F.

    1972-01-01

    The synthesis of 14 C uniformly labelled compounds is described. By polymerization of 14 C ethylene, linear olefins with a double bond at α position were obtained. From these olefins, uniformly labelled alkanes, alcohols and acids were prepared [fr

  19. 14C age determination for human bones during the Yayoi period - the calibration ambiguity around 2400 BP and the marine reservoir effect

    International Nuclear Information System (INIS)

    Mihara, S.; Miyamoto, K.; Nakamura, T.; Koike, H.

    2004-01-01

    14 C ages for Japanese prehistoric samples from the Latest Jomon period to the early Yayoi period have a calibration ambiguity for dates around 2400 BP. It is also necessary to correct for the marine reservoir effect on 14 C ages of human bone samples from people who consumed marine food as a protein source. The Ohtomo site in western Japan, is a cemetery site used from the end of the Latest Jomon period to the Kofun period, provide a useful archaeological chronology. Human bones found in dolmen burials, jar burials and cist burials. In this study, we determined the 14 C ages of human bone samples and calculated the marine reservoir effect, using diet analysis based on carbon and nitrogen stable isotopes. Diet analysis showed that these people obtained from 40% to 60% of their protein from marine sources. Their 14 C ages with calibration and marine reservoir correction were serially matched with the archaeological chronology

  20. Radiocarbon (14C) Concentration of Local Pollution in Street Trees Located at Intersections

    OpenAIRE

    Ogawa, Daisuke

    2018-01-01

    At large intersections, vehicles consume and generate a large amount of fossil fuel. Carbon derived from fossil fuels that do not contain radioactive carbon (14C), i.e., dead carbon, is released in large amounts in the roadside air environment. By means of photosynthesis, street trees along the roadside assimilate both dead carbon, not containing radioactive carbon (14C), and contemporary carbon, which includes radioactive carbon (14C). Therefore, the concentration of radioactive carbon (14C)...