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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. 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

  3. High-resolution chronologies for loess: comparing AMS 14C and optical dating results

    Science.gov (United States)

    Lang, A.; Hatté, C.; Rousseau, D.-D.; Antoine, P.; Fontugne, M.; Zöller, L.; Hambach, U.

    2003-05-01

    The Nußloch loess section in South West Germany is famous in Central Europe for its thick deposits from the Last Glacial Maximum. It has therefore been intensively studied during the past few years and offers an excellent opportunity to compare the performance of different dating techniques covering the period 15-45 ka. Here we present results from optical and AMS 14C dating. The silt-sized polymineral fraction of the clastic sediments and a multiple-aliquot approach was used for IR-OSL dating. 14C dating was carried out on organic macro-remnants and humin fractions extracted from the sediments. With the exception of samples taken from the uppermost 1.5 m of the section, IR-OSL and calibrated 14C-AMS ages are consistent over the entire period. The inconsistencies in the upper meters are thought to be due to disturbances during soil formation in the Holocene. The good agreement obtained on the remaining sequence demonstrates the high accuracy of both methods when studying loess sections: for the IR-OSL ages no significant age underestimations are obvious. The results clearly document that accurate chronologies can be developed for such continental sedimentary sequences. This gives access to archives that can now be studied with a high temporal resolution and allows the establishment of new paleoclimatic proxies for the study of terrestrial responses to past climatic changes.

  4. 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.)

  5. 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.

  6. 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.

  7. Influence of increasing combustion temperature on the AMS 14C dating of modern crop phytoliths.

    Science.gov (United States)

    Yin, Jinhui; Yang, Xue; Zheng, Yonggang

    2014-10-07

    Several attempts have been made to directly date phytoliths, but most (14)C results are not consistent with other independent chronologies. Due to the limited dataset, there is not a clear explanation for these discrepancies. Herein, we report the (14)C ages of phytolith-occluded carbon (PhytOC) from contemporary rice and millet crops that were combusted at different temperatures to investigate the relationship between the combustion temperature and resulting (14)C age. Our results show that the (14)C age of PhytOC increases directly with combustion temperature (up to 1100°C) and results in age overestimations of hundreds of years. Considerably older ages are observed at higher temperatures, suggesting that it may be possible to distinguish between two fractions of organic carbon in phytoliths: labile and recalcitrant carbon. These findings challenge the assumption that PhytOC is homogeneous, an assumption made by those who have previously attempted to directly date phytoliths using (14)C.

  8. What are we Dating? An Evaluation of Chemical Pretreatment Methods for AMS 14C Dating of Peat

    Science.gov (United States)

    Scharer, K.; Kashgarian, M.; Zermeno, P.; Kurdyla, D.

    2006-12-01

    Progressive deformation of landforms commonly creates depositional environments where organic-rich sediment layers such as peats are preserved (e.g., Wrightwood, Coachella, Vedanta paleoseismic sites). Field studies using 3-D excavation methods can improve estimates of landform displacement, while AMS 14C dating of well characterized organic material sampled during field work is essential for determining slip rates associated with landform deformations. Here we present results of a test of chemical pretreatment used for AMS 14C dating of peat in an attempt to better characterize what we are dating and how the age of organic fractions is affected by different extraction procedures. Standard chemical pretreatment of organic materials for AMS 14C analysis typically isolates three broad organic fractions: humic acids, humin, and fulvic acids. Humic acids, the focus of this study, are thought to result from complex degradation of lignin and related compounds, and in principle should provide the most accurate age of in-situ organic layers (i.e., the decomposed leaf of a plant). The extraction of humic acid from organic-rich sediments or soils is operationally defined by chemical solubility and is not directly associated with a particular starting material. This means that chemical extracts are likely to contain humic acids derived from different starting materials which may have different ages and origins. In earlier studies of the duration of chemical pretreatment, Cook et al. (1998) found that increasing the amount of time that peat was exposed to NaOH increased the quantity of humics extracted, and Williams (1989) reported that increasing the duration of the NaOH wash will sometimes, but not always, result in an older sample age. Thus, a long base extraction time may solubilize more resistant and potentially older humics. To test whether the duration of the base extraction step affects dates, we extracted humic acid from three peat layers from the Wrightwood

  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. Dating Danish textiles and skins from bog finds by means of 14C AMS

    DEFF Research Database (Denmark)

    Mannering, Ulla; Possnert, Göran; Heinemeier, Jan

    2010-01-01

    This paper presents the results of 44 new 14C analyses of Danish Early Iron Age textiles and skins. Of 52 Danish bog finds containing skin and textile items, 30 are associated with bog bodies. Until now, only 18 of these have been dated. In this paper we add dates to the remaining finds. The resu......This paper presents the results of 44 new 14C analyses of Danish Early Iron Age textiles and skins. Of 52 Danish bog finds containing skin and textile items, 30 are associated with bog bodies. Until now, only 18 of these have been dated. In this paper we add dates to the remaining finds....... The results demonstrate that the Danish custom of depositing clothed bodies in a bog is centred to the centuries immediately before and at the beginning of the Common Era. Most of these bodies are carefully placed in the bog - wrapped or dressed in various textile and/or skin garments....

  11. AMS 14C and 230Th/U dating on stalagmites from North Altai Mountain, Siberia, Russia

    Science.gov (United States)

    Li, H. C.; Yin, J. J.; Blyakharchuk, T.; Shen, C. C.

    2017-12-01

    Three stalagmites, two from Lunnaya Cave (LUN-1 and LUN-2, 52º40.729'N, 88º43.854' E, 481 m a.s.l.), one from Nadezhda Cave (HOP-1, 52º38.872'N, 88º39.194'E, 550 m a.s.l.) located along Mrassy River in the northern Altai Mountains, Siberia, Russia were collected in the summer of 2016 for paleoclimate reconstruction. HOP-1 is a 21-cm long stalagmite which contains very low U content (238U = 70 ppb) and relatively high Th content (232Th = 2 9.3 ppb), resulting in unsuccessful 230Th/U dating (-262 ± 284 yr BP in the top and -19,935 ± 22,246 yr BP). Thirty one AMS 14C dates from 27 horizons of the stalagmite provide a detailed chronology, showing that the stalagmite grew from 6,350 ± 45 yr BP to 490 ± 10 Calib. yr BP. Both LUN-1 and LUN-2 are about 20-cm long. The growth feature of LUN-2 is similar to that of HOP-1 with continuous growth, clear bands of depositional cycles in white non-transparent calcite, whereas LUN-1 has light yellow transparent calcite in the center part with multiple growth hiatuses. The 230Th/U dates show that LUN-1 from 2725 ± 775 yr BP at 193 mm depth to 823 ± 28 yr BP at 12 mm depth with very fast growth rate during 900 1500 yr BP. The AMS 14C dates of LUN-1 provide similar growth pattern with very fast growth between the first hiatus at 12 mm depth and the second hiatus at 155 cm depth. Six 14C dates from this fast growth period are all around 1500 Calib. yr BP without a correct age sequence. Two 14C dates from the top 12 mm exhibit "nuclear bomb signal" (percentage of modern carbon >100%). Similar ages of AMS 14C and 230Th/U dating results in the lower part indicate that dead carbon influence in radiocarbon ages are negligible. 230Th/U dating is not successful for LUN-2. The preliminary AMS 14C dating on LUN-2 shows that the stalagmite continuously deposited from 13335 ± 150 Calib. yr BP. All three stalagmites do not have growth deposition during the Little Ice Age due to cold and dry climates. Further work on stable isotope

  12. 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

  13. 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

  14. 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

  15. 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

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

    Science.gov (United States)

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

    2004-08-01

    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.

  17. IBA analyses and lead concentration measurements of AMS- 14C dated bones from two medieval sites in Italy

    Science.gov (United States)

    Quarta, Gianluca; Butalag, Karim; Calcagnile, Lucio; D'Elia, Marisa; Arthur, Paul; Tinelli, Marisa; Caramia, Annalisa

    2008-05-01

    AMS (accelerator mass spectrometry) radiocarbon dated human bone samples recovered in the deserted medieval village of Quattro Macine, Lecce, in Southern Italy, were analyzed by PIXE (particle induced X-ray emission) and PIGE (particle induced gamma ray emission). The optimization of the PIXE-PIGE experimental set-up in term of beam energy and detection geometry resulted in the possibility to obtain information about major, minor and trace elements of the samples. Unexpectedly, all the analyzed samples showed a Pb concentration higher than 50 ppm. Two possible explanations of the measured high Pb concentration are discussed in the paper: the pre-mortem intake associated with the use of Pb-rich glazed pottery and the post-mortem intake from soil as the result of diagenetic processes.

  18. The necessity of sample quality assessment in {sup 14}C AMS dating: The case of Cova des Pas (Menorca - Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Strydonck, Mark Van, E-mail: mark.vanstrydonck@kikirpa.b [Royal Institute for Cultural Heritage, Jubelpark 1, B-1000 Brussels (Belgium); Boudin, Mathieu [Royal Institute for Cultural Heritage, Jubelpark 1, B-1000 Brussels (Belgium); Guerrero Ayuso, Victor M.; Calvo, Manuel [Universidad de las Islas Baleares, Edifici Ramon Llull, C. Valldemossa km 7.5, E-07071 Palma de Mallorca (Spain); Fullola, Josep M.; Angeles Petit, M. [Seminari d' Estudis i Recerques Prehistoriques (S.E.R.P.), Dept. of Prehistory, Ancient History and Archaeology, University of Barcelona Montalegre St. 6, E-08001 Barcelona (Spain)

    2010-04-15

    The Cova des Pas cave is a karstic cave in the cliffs of the Barranc (canyon) de Trebaluger. It is a small cave only 6.5 m deep, 4.5 m wide and 1.7 m high. Yet more than 70 burials, in foetal position, from the Early Iron Age were found in this small cave. The conservation of the archaeological remains was very unusual. Not only wood, ropes and other plant material was found, but also remains of body tissue, hair and leather. In spite of the remarkable preservation of the bodies and artefacts, the state of conservation of the bone material was very bad. The bones contained little and heavily deteriorated collagen and the organic plant material was very fragile. The special environmental conditions of the cave are the cause of these unusual preservation conditions. Although the cave is situated in a limestone cliff, the soil of the cave is very acid. Unexpectedly bad sample quality seemed to be the major drawback for AMS radiocarbon dating on hair, wood, ropes and bone collagen, as well as on bio-apatite.

  19. The necessity of sample quality assessment in 14C AMS dating: The case of Cova des Pas (Menorca - Spain)

    International Nuclear Information System (INIS)

    Strydonck, Mark Van; Boudin, Mathieu; Guerrero Ayuso, Victor M.; Calvo, Manuel; Fullola, Josep M.; Angeles Petit, M.

    2010-01-01

    The Cova des Pas cave is a karstic cave in the cliffs of the Barranc (canyon) de Trebaluger. It is a small cave only 6.5 m deep, 4.5 m wide and 1.7 m high. Yet more than 70 burials, in foetal position, from the Early Iron Age were found in this small cave. The conservation of the archaeological remains was very unusual. Not only wood, ropes and other plant material was found, but also remains of body tissue, hair and leather. In spite of the remarkable preservation of the bodies and artefacts, the state of conservation of the bone material was very bad. The bones contained little and heavily deteriorated collagen and the organic plant material was very fragile. The special environmental conditions of the cave are the cause of these unusual preservation conditions. Although the cave is situated in a limestone cliff, the soil of the cave is very acid. Unexpectedly bad sample quality seemed to be the major drawback for AMS radiocarbon dating on hair, wood, ropes and bone collagen, as well as on bio-apatite.

  20. AMS 14C dating of wooden anchors and planks excavated from submerged wrecks located at Takashima in Imari Bay, Nagasaki prefecture

    International Nuclear Information System (INIS)

    Suzuki, Kazuhiro; Oda, Hirotaka; Niu, Etsuko; Ikeda, Akiko; Nakamura, Toshio; Ogawa, Mitsuhiko; Matsuo, Akiko

    2001-01-01

    According to folklore the fleet that was dispatched to Japan for the second Mongol invasion of 1281 encountered a fierce typhoon at Takashima. Radiocarbon ( 14 C) ages of wooden anchors and planks excavated from the submerged site at Takashima were determined using accelerator mass spectrometry (AMS). The 14 C ages are 745±20 BP for bamboo and 770±20 BP for wood from the intact wooden anchor, and 840±20 / 865±20 BP for the planks, respectively. The calibrated bamboo age of 1268-1284 cal AD and the slightly older age of 1257-1279 cal AD for wood suggest that the wooden anchor was manufactured just before the invasion. The age range of planks (1191-1236 and 1163-1215 cal AD) is consistent with an idea that they are likely to be derived from contemporaneous ships. The high-precision AMS 14 C dating confirms that the wooden anchors and planks are remains of wrecked Mongolian warships that were involved in the second Mongol invasion. (author)

  1. 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)

  2. 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

  3. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Penny, Dan [School of Geosciences, University of Sydney, NSW 2006 (Australia); Hua, Quan [Australian Nuclear Science and Technology Organisation, PMB 1, Menai, NSW 2234 (Australia)]. E-mail: qhx@ansto.gov.au; Pottier, Christophe [Ecole Francaise d' Extreme Orient, P.O. Box 93300, Siem Reap (Cambodia); Fletcher, Roland [Department of Archaeology, University of Sydney, NSW 2006 (Australia); Barbetti, Mike [Department of Archaeology, University of Sydney, NSW 2006 (Australia); Radiogenic Isotope Laboratory, University of Queensland, Brisbane, QLD 4072 (Australia)

    2007-06-15

    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.

  5. 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)

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. {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)

  12. The 14C AMS system at The University of Georgia

    Science.gov (United States)

    Roberts, M. L.; Culp, R. A.; Dvoracek, D. K.; Hodgins, G. W. L.; Neary, M. P.; Noakes, J. E.

    2004-08-01

    The Center for Applied Isotope Studies at the University of Georgia has installed a compact 14C accelerator mass spectrometry (AMS) system manufactured by the National Electrostatics Corporation, Middleton, Wisconsin. The system utilizes a 134 sample ion source and a 500 kV Pelletron. In terms of cost and size, the new system is a significant advance over previous technology. Details and performance of the new system will be presented.

  13. Pyrolysis-combustion 14C dating of soil organic matter

    Science.gov (United States)

    Wang, Hongfang; Hackley, Keith C.; Panno, S.V.; Coleman, D.D.; Liu, J.C.-L.; Brown, J.

    2003-01-01

    Radiocarbon (14C) dating of total soil organic matter (SOM) often yields results inconsistent with the stratigraphic sequence. The onerous chemical extractions for SOM fractions do not always produce satisfactory 14C dates. In an effort to develop an alternative method, the pyrolysis-combustion technique was investigated to partition SOM into pyrolysis volatile (Py-V) and pyrolysis residue (Py-R) fractions. The Py-V fractions obtained from a thick glacigenic loess succession in Illinois yielded 14C dates much younger but more reasonable than the counterpart Py-R fractions for the soil residence time. Carbon isotopic composition (??13C) was heavier in the Py-V fractions, suggesting a greater abundance of carbohydrate- and protein-related constituents, and ??13C was lighter in the Py-R fractions, suggesting more lignin- and lipid-related constituents. The combination of 14C dates and ??13C values indicates that the Py-V fractions are less biodegradation resistant and the Py-R fractions are more biodegradation resistant. The pyrolysis-combustion method provides a less cumbersome approach for 14C dating of SOM fractions. With further study, this method may become a useful tool for analyzing unlithified terrestrial sediments when macrofossils are absent. ?? 2003 University of Washington. Published by Elsevier Inc. All rights reserved.

  14. 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)

  15. 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.

  16. 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.

  17. 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.

  18. 14C Dating for the Younger Unzen Volcano, Japan

    Science.gov (United States)

    Xu, S.; Xu, S.; Hoshizumi, H.; Ochiai, Y.; Aoki, H.; Uto, K.

    2001-12-01

    Unzen volcano is situated in a volcanotectonic depression, ~70 km west of the volcanic front of SW Japan. The volcanic products of Unzen volcano cover a wide area with many lava domes, thick lava flows, and pyroclastic deposits of andesite to dacite composition. The composite volcanic edifice can be subdivided into Older and Younger Unzen volcanoes. The Older Unzen volcano (500-200 ka) is thought to be a complex volcanic edifice originally centered near the present Younger Unzen volcano, but it has been displaced by several faults and deeply eroded. The Younger Unzen volcano (soil organic carbon of bulk sample underlying the volcanic eruption products. The 14C dating of the bulk soil organic matter is a polemic subject, mainly due to the complexity of the soil formation and to the variable contamination from several sources. The reliabilty of most 14C dates for buried soils in this study was supported by lack of significant age deviations in double organic extracts of soil (humin and humic acid fractions), agreement of dating results obtained for different materials (buried soil and charcoal), and normal sequence in soil-pyroclastic/lava sections. The 14C results based on surface and USDP borehole materials clarified the initial eruption ages of the Younger Unzen volcano, i.e., Myokendake: 35 ka; Fugendake: 25 ka; and Mayuyama: 4.5 ka BP. In particular, the Fugendake volcano is characterized by the repeated eruptions occurred at 24, 20, 19, 14, 11, 10, 9, 7, 4, 1.6 ka BP and recently AD 1300, 1663, 1792 and 1991 ~95.

  19. 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

  20. Fine resolution AMS 14C chronology for Lunette-Lake sediment sequences, Lake Bolac, Victoria

    International Nuclear Information System (INIS)

    Cook, E.

    1998-01-01

    This study aims to provide a fine-resolution chronology for lake sediment records from Lakes Bolac and Turangmoroke, located within the drier part of the Western Plains, Victoria. These lakes are expected to be sensitive to subtle climate and vegetation variability and have long been recognised as archaeologically rich, bearing stone tools, hearth and other cultural materials dated to the late Pleistocene (Horton, 1984; former Victorian Aboriginal Survey, unpublished data). Fine-resolution chronological control has rarely been attempted in this sedimentary and (semi-arid) climatic context owing to the paucity of material available for conventional 14 C dating. However, pollen and microscopic charcoal in the lake sediments at Bolac and Turangmoroke are suitable for AMS age determination with the most important sedimentary section well within the range of 14 C making them ideal records for such a study. Recent dating results, which have substantially increased chronostratigraphic interpretation of concurrent palaeoecological and sedimentological work in progress, are presented

  1. Fine resolution AMS {sup 14}C chronology for Lunette-Lake sediment sequences, Lake Bolac, Victoria

    Energy Technology Data Exchange (ETDEWEB)

    Cook, E. [Monash University, Clayton, VIC (Australia). Centre for Palynology and Palaeoecology, Department of Geography and Environmental Science

    1998-12-31

    This study aims to provide a fine-resolution chronology for lake sediment records from Lakes Bolac and Turangmoroke, located within the drier part of the Western Plains, Victoria. These lakes are expected to be sensitive to subtle climate and vegetation variability and have long been recognised as archaeologically rich, bearing stone tools, hearth and other cultural materials dated to the late Pleistocene (Horton, 1984; former Victorian Aboriginal Survey, unpublished data). Fine-resolution chronological control has rarely been attempted in this sedimentary and (semi-arid) climatic context owing to the paucity of material available for conventional {sup 14}C dating. However, pollen and microscopic charcoal in the lake sediments at Bolac and Turangmoroke are suitable for AMS age determination with the most important sedimentary section well within the range of {sup 14}C making them ideal records for such a study. Recent dating results, which have substantially increased chronostratigraphic interpretation of concurrent palaeoecological and sedimentological work in progress, are presented

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

    Energy Technology Data Exchange (ETDEWEB)

    Fiorentino, G., E-mail: girolamo.fiorentino@ateneo.unile.i [Laboratory of Archaeobotany and Palaeoecology, Department of Cultural Heritage, University of Salento, Lecce (Italy); Caracuta, V. [Laboratory of Archaeobotany and Palaeoecology, Department of Cultural Heritage, University of Salento, Lecce (Italy); Dipartimento di Scienze Umane, Sezione di Archeologia, University of Foggia (Italy); Volpe, G.; Turchiano, M. [Dipartimento di Scienze Umane, Sezione di Archeologia, University of Foggia (Italy); Quarta, G.; D' Elia, M.; Calcagnile, L. [CEDAD (Centre for Dating and Diagnostics), Department of Innovation Engineering, University of Salento, Lecce (Italy)

    2010-04-15

    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 delta{sup 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.

  3. 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.

  4. 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)

  5. 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.

  6. 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.

  7. 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

  8. 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)

  9. Problems encountered with the 14C dating of peat

    Science.gov (United States)

    Shore, J. S.; Bartley, D. D.; Harkness, D. D.

    Pairs of neighbouring short columns of peat from two sites in Northern England were divided into contiguous 1 cm thick slices that were sub-sampled for pollen and plant macro fossil analysis. For each slice the remaining peat was then split into humic acid, humin and fulvic acid fractions and radiocarbon dated. This research demonstrates that significant variations can occur in the radiocarbon content of discrete chemically defined fractions of peat. A total of 127 radiocarbon dates was obtained. The results from the four columns of peat are highly variable and mutually inconsistent. The fulvic acid fraction, although normally younger than the corresponding humic acid and humin fractions, has very little effect on a combined date in these samples. However, it is removed from all samples prior to dating in order to remove any carbonates which could contaminate samples. The variations in the ages obtained for the humic acid and corresponding humin fractions range from the humin fraction being 630 years older than the humic acid (SRR-4029) to the humic acid being 1210 years older than the humin fraction (SRR-4007), even when a two sigma confidence is allowed. No correlation was apparent between pollen concentration, 13C enrichment, degree of humification and the conventional radiocarbon ages.

  10. 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.)

  11. 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

  12. 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)

  13. Simultaneous AMS determination of {sup 14}C content and total carbon mass in biological samples

    Energy Technology Data Exchange (ETDEWEB)

    Zoppi, U., E-mail: uzoppi@acciumbio.co [Accium BioSciences, 550 17th Avenue, Suite 550, Seattle, WA 98122 (United States); Arjomand, A. [Accium BioSciences, 550 17th Avenue, Suite 550, Seattle, WA 98122 (United States)

    2010-04-15

    Accelerator Mass Spectrometry (AMS) is now recognized as one of the most powerful techniques available for conducting ultrasensitive clinical studies. However, since for biological applications the relevant quantity is the total {sup 14}C activity (i.e. dpm/mL sample), AMS {sup 14}C measurements must be combined with total carbon concentrations measured on a separate instrument using a different sample aliquot. This procedure is inherently a source of large inaccuracies, especially in non-homogeneous samples such as urine and fecal blends. To overcome this limitation we developed a new measurement technique whereby a small amount of {sup 13}C-enriched carbon carrier is added to each sample. Accurate measurement of the {sup 13}C/{sup 12}C and {sup 14}C/{sup 13}C ratios of the mix can be used to simultaneously calculate total carbon mass and {sup 14}C concentration of the original sample. In this paper we present our first test runs including a detailed error analysis demonstrating that sample mass and {sup 14}C concentration of the original sample can be determined with a precision and accuracy of better than 3%, thus significantly reducing the final uncertainty due to sample in-homogeneities.

  14. 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.

  15. 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.

  16. 14C AMS measurements of tree leaf samples to monitor air pollution induced by city traffic

    International Nuclear Information System (INIS)

    Kim, J.C.; Kim, I.C.; Park, J.H.; Park, S.H.

    2000-01-01

    In the past, many radiocarbon measurement have been made for environmental studies such as source apportionment of air-borne particulates, and studies of the anthropogenic effects of nuclear power plants. In this presentation we report our accelerator mass spectrometry (AMS) measurements of radiocarbon on tree leaf samples to investigate the impact of city traffic on our living-environment. The fossil-burning vehicles emit carbon dioxide (CO 2 ) free of 14 C content and, when mixed with the clean air CO 2 , lower 14 C ratio compared to the normal reservoir value. This so-called Suess effect can be incorporated to monitor air quality in our living environments, since metabolic processes maintain the 14 C content of living organism in equilibrium with atmospheric 14 C. In other words, dead CO 2 is admixed to the normal atmospheric CO 2 and then photo-synthetically assimilated by the plants. Two kinds of tree leaf samples; pine tree needles and Ginkgo tree leaves were collected during a one-week period in the summer 1996 at five different locations with various traffic conditions in the region, within a 10-km diameter circle, south of the River Han, Seoul. The AMS targets were made by a simple sample-making procedure. The leaves have been pretreated by a standard acid-alkali treatment and then charred in a vacuum evaporator by applying ca. 800 deg C heat. The charred samples were mixed with Ag powder and pressed into the Al target holder for the AMS measurement.The AMS measurements were made using the accelerator mass spectrometry facilities of the Leibniz-Labor at the Christian-Albrecht University, Kiel,Germany. The observed Δ 14 C values, which ranged from 60 TM to 158 TM , have a good correlation with the traffic conditions in the places where the sampling took place and show a remarkable capability of 14 C AMS measurements to monitor our fossil burning environment. The volume ratios of clean air to air from fossil-burn origin in the environmental CO 2 reached to

  17. 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

  18. 14C dating of bone using (gamma) Carboxyglutamic Acid and Carboxyglycine (Aminomalonate)

    Energy Technology Data Exchange (ETDEWEB)

    Southon, J R; Burky, R T; Kirner, D L; Taylor, R E; Hare, P E

    1999-04-27

    Radiocarbon determinations have been obtained on {gamma}-carboxyglutamic acid [Gla] and {alpha}-carboxyglycine (aminomalonate) [Am] as well as acid- and base-hydrolyzed total amino acids isolated from a series of fossil bones. As far as they are aware, Am has not been reported previously in fossil bone and neither Gla nor Am {sup 14}C values have been measured previously. Interest in Gla, an amino acid found in the non-collagen proteins osteocalcin and matrix Gla-protein (MGP), proceeds from the suggestion that it may be preferentially retained and more resistant to diagenetic contamination affecting {sup 14}C values in bones exhibiting low and trace amounts of collagen. The data do not support these suggestions. The suite of bones examined showed a general tendency for total amino acid and Gla concentrations to decrease in concert. Even for bones retaining significant amounts of collagen, Gla (and Am extracts) can yield {sup 14}C values discordant with their expected age and with {sup 14}C values obtained on total amino-acid fractions isolated from the same bone sample.

  19. The {sup 14}C AMS system at The University of Georgia

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, M.L. E-mail: mroberts@whoi.edu; Culp, R.A.; Dvoracek, D.K.; Hodgins, G.W.L.; Neary, M.P.; Noakes, J.E

    2004-08-01

    The Center for Applied Isotope Studies at the University of Georgia has installed a compact {sup 14}C accelerator mass spectrometry (AMS) system manufactured by the National Electrostatics Corporation, Middleton, Wisconsin. The system utilizes a 134 sample ion source and a 500 kV Pelletron. In terms of cost and size, the new system is a significant advance over previous technology. Details and performance of the new system will be presented.

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

    Science.gov (United States)

    Kjeldsen, Henrik; Olsen, Jesper; Heinemeier, Jan

    2010-04-01

    AMSdata is the name of a combined database and data-analysis system for AMS 14C 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 14C 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.

  1. 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.

  2. Accelerator 14C dates for early upper paleolithic (basal Aurignacian) at El Castillo Cave (Spain)

    Science.gov (United States)

    Valdes, V.C.; Bischoff, J.L.

    1989-01-01

    Three fragments of charcoal taken from different parts of the lowermost bed containing Aurignacian artifacts at El Castillo Cave yielded AMS dates of 37??7 (?? 1??8) ka bp, 38??5 (?? 1??8) ka bp, and 40??0 (?? 2??1) ka bp (average 38??7 ?? 1??9 ka bp). These dates are almost identical to new AMS dates from l'Arbreda cave in Catalunya on the same cultural horizon (average 38??5 ?? 1??0 ka bp) and are significantly older than the earliest dates for Aurignacian industries in the Aquitaine and in other parts of Central and Western Europe. ?? 1989.

  3. {sup 14}C dating of the Early to Late Bronze Age stratigraphic sequence of Aegina Kolonna, Greece

    Energy Technology Data Exchange (ETDEWEB)

    Wild, E.M., E-mail: Eva.Maria.Wild@univie.ac.a [VERA Laboratory, Faculty of Physics - Isotope Research, University of Vienna, Waehringer Strasse 17, A-1090 Wien (Austria); Gauss, W. [Austrian Archaeological Institute at Athens, Leof. Alexandras 26, Gr10683 Athens (Greece); Forstenpointner, G. [University of Veterinary Medicine Vienna, Dept. of Pathobiology, Institute of Anatomy, Unit on Archaeozoology and Comparative Morphology, Veterinaerplatz 1, A-1210 Vienna (Austria); Lindblom, M. [Dept. of Archaeology and Ancient History Uppsala, University Box 626, SE-751 26 Uppsala (Sweden); Smetana, R. [Altertumswissenschaften, University of Salzburg, Residenzplatz 1/I, A-5020 Salzburg (Austria); Steier, P. [VERA Laboratory, Faculty of Physics - Isotope Research, University of Vienna, Waehringer Strasse 17, A-1090 Wien (Austria); Thanheiser, U. [Vienna Institute for Archaeological Science (VIAS), Althanstrasse 14, A-1090 Vienna (Austria); Weninger, F. [VERA Laboratory, Faculty of Physics - Isotope Research, University of Vienna, Waehringer Strasse 17, A-1090 Wien (Austria)

    2010-04-15

    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 {sup 14}C-dated with the AMS method at the VERA laboratory. Bayesian sequencing of the {sup 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 {sup 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.

  4. 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.

  5. 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.

  6. 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

  7. Ion-optics calculations of the LLNL AMS system for biochemical 14C measurements

    Science.gov (United States)

    Ognibene, T. J.; Brown, T. A.; Knezovich, J. P.; Roberts, M. L.; Southon, J. R.; Vogel, J. S.

    2000-10-01

    A dedicated AMS system for biochemical 14C measurements is being built at the Center for Accelerator Mass Spectrometry. The system is centered around a National Electrostatics Corporation Model 3SDH-1 1-MV Pelletron accelerator and is designed to accept two ion sources. The LLNL 64-sample Cs-sputter ion source with its zoom lens beam line is attached to one port of the electrostatic switching element. To insure efficient coupling of the source to the acceptance of the accelerator, ion-optics calculations of the low-energy injection beam line have been conducted; the results of which were used to determine the layout of the ion-optical components of the beam line. Beam tests of the low-energy injection line show that beam behavior was accurately predicted by the calculations.

  8. 14C dating with the bomb peak: An application to forensic medicine

    International Nuclear Information System (INIS)

    Wild, E.M.; Arlamovsky, K.A.; Golser, R.; Kutschera, W.; Priller, A.; Puchegger, S.; Rom, W.; Steier, P.; Vycudilik, W.

    2000-01-01

    Samples originating from the time period after 1950 can be radiocarbon dated utilising the 14 C bomb peak as a calibration curve. The applicability of 'radiocarbon dating' of recent organic human material for the determination of the time of death of humans was tested. The radiocarbon results from hair and lipid samples from individuals with known date of death were compared with the results from two individuals with unknown time of death. An estimate of the year of death for the unknowns could be derived by this way. Due to the long turnover time of collagen in human bones it is not possible to use the radiocarbon content of bone collagen for a reliable estimate. In order to study the time dependence of the collagen turnover we tested 'soft' chemical methods for the isolation of collagen from the bone matrix. First radiocarbon results of this investigation are presented

  9. 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.

  10. 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.

  11. Online coupling of pure O2 thermo-optical methods – 14C 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 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 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 14 C aerosol source apportionment.

  12. 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

  13. 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

  14. 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.

  15. 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

  16. 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.

  17. Cross-checking groundwater age by 4He and 14C dating in a granite, Tono area, central Japan

    Science.gov (United States)

    Hasegawa, Takuma; Nakata, Kotaro; Tomioka, Yuichi; Goto, Kazuyuki; Kashiwaya, Koki; Hama, Katsuhiro; Iwatsuki, Teruki; Kunimaru, Takanori; Takeda, Masaki

    2016-11-01

    Groundwater dating was performed simultaneously by the 4He and 14C methods in granite of the Tono area in central Japan. Groundwater was sampled at 30 packed-off sections of six 1000-m boreholes. 4He concentrations increased and 14C concentrations decreased along a groundwater flow path on a topographic gradient. 4He ages were calculated by using the in situ 4He production rate derived from the porosity, density, and U and Th content of the rock, neglecting external flux. 14C ages were calculated with a noncorrected model in which the initial 14C content was 100 percent of the modern radiocarbon level (Co = 100 pmC), a statistical model using the average 14C content of tritium-bearing samples (Co = 46.4 pmC), and a δ13C model based on the isotopic mass balance. Although the absolute 14C ages calculated by the models were different, the relative 14C ages were almost identical. The relative 14C ages were considered reliable because dissolved inorganic carbon has no significant geochemical reactions in granite. The relation between the 4He ages and the noncorrected 14C ages was [4He age] = 1.15 [14C age] + 7200 (R2 = 0.81), except in the discharge area. The slope of this relation was equivalent to unity, which indicates that the 4He accumulation rate is confirmed by the relative 14C ages. Moreover, the accumulated 3He/4He ratio was equivalent to that derived from the 6Li(α,n)3H reaction in granite. These results show that the accumulated He is of crustal origin, produced in situ without external flux, except in the discharge area. The intercept value of 7200 a implies that the 14C concentrations were diluted due to geochemical reactions. Tritium-bearing samples supported this result. Simultaneous measurements make it feasible to estimate the accumulation rate of 4He and initial dilution of 14C, which cannot be done with a single method. Cross-checking groundwater dating has the potential to provide more reliable groundwater ages. The circulation time of the

  18. 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.

  19. AMS Radiocarbon dating of paleosols intercalated with tephra layers from Mayon Volcano, southern Luzon, Philippines: A preliminary report

    Science.gov (United States)

    Mirabueno, Ma. Hannah T.; Okuno, Mitsuru; Nakamura, Toshio; Newhall, Christopher G.; Kobayashi, Tetsuo

    2006-01-01

    This paper presents the AMS 14C dates of paleosols intercalated with tephra layers in the vicinity of Mayon Volcano, southern Luzon, Philippines. the obtained 14C dates are almost consistent with the stratigraphy of the Mayon tephra group. On the basis of calibrated 14C age of soil layer directly overlying the lowest ash layer, the oldest eruptive event must have taken place shortly before 20 cal kyr BP. This age is younger than the previous estimates for Mayon.

  20. 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.

  1. 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...

  2. 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

  3. 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).

  4. Ion source improvements at the Jena {sup 14}C-AMS facility

    Energy Technology Data Exchange (ETDEWEB)

    Steinhof, Axel, E-mail: steinhof@bgc-jena.mpg.de [Max-Planck-Institut fuer Biogeochemie, Jena (Germany); Baatzsch, Andreas, E-mail: baatzsch@googlemail.com [Max-Planck-Institut fuer Biogeochemie, Jena (Germany); Hejja, Istvan, E-mail: hejja@bgc-jena.mpg.de [Max-Planck-Institut fuer Biogeochemie, Jena (Germany); Wagner, Thomas, E-mail: twagner@bgc-jena.mpg.de [Max-Planck-Institut fuer Biogeochemie, Jena (Germany)

    2011-12-15

    We report on an ongoing program of improvements of the Jena AMS system. The present contribution focuses on the improvement of the High Voltage Engineering Europe (HVEE) ion source 846. Furthermore it is described how the usable current range is determined at the Jena lab.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. Two years since SSAMS: Status of 14C AMS at CAIS

    Science.gov (United States)

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

    2015-10-01

    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.

  10. {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.

  11. 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

  12. 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'

  13. 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'.

  14. EU/Th AND 14 C isotope dating of lake sediments from sacred lake ...

    African Journals Online (AJOL)

    In the tropical regions, lake and swamp sediment core chronologies have traditionally been established solely by radiocarbon dating. In several instances, however, the radiocarbon sampling resolution has been coarse, entailing extrapolations over time periods where there may have been considerable change in ...

  15. 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)

  16. 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.

  17. 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)

  18. 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.

  19. 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

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

    Science.gov (United States)

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

    2015-10-01

    The carbon dioxide contributing to binder formation during the set of a lime mortar reflects the atmospheric 14C content at the time of construction of a building. For this reason, the 14C 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 14C 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 14C 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 about the

  1. 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 14 C content at the time of construction of a building. For this reason, the 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 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 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 and to infer about

  2. 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)

  3. 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.

  4. The AMS dating of pollen from syngenetic ice-wedge ice

    Energy Technology Data Exchange (ETDEWEB)

    Vasil' chuk, Alla C. E-mail: vasilch@orc.ru; Kim, Jong-Chan; Vasil' chuk, Yurij K

    2004-08-01

    The features of pollen occurrence in ice-wedge ice such as: size of pollen of tundra plants, incoming pollen into frost cracks together with melt water, dust and partially from host sediment and also clay envelopes around pollen grains caused the pretreatment methods of ice-wedge ice samples. Good preservation of thin-wall pollen grains of Salix and Liliaceae after pretreatment evidenced appropriate pretreatment procedure. There is evident correlation between pollen dates and re-deposited pollen and spores content. However an interpretation of {sup 14}C dating of pollen concentrate is required independent time scale such as annual laminas or the AMS dates of macro or microfossils.

  5. Palaeomagnetic intensities from 14C-dated lava flows on the Big Island, Hawaii: 0-21 kyr

    Science.gov (United States)

    Pressling, Nicola; Laj, Carlo; Kissel, Catherie; Champion, Duane E.; Gubbins, David

    2006-01-01

    Thellier–Thellier experiments were carried out on 216 lava samples collected by the USGS on the Big Island. 35 individual flows from the Kilauea, Mauna Loa and Hualalai volcanoes are represented and independent radiocarbon dating of the flows yields absolute ages ranging from 290 to 20,240 yrs old. The palaeomagnetic analysis was carried out at the Laboratoire des Sciences du Climat et de l'Environnement in Gif-sur-Yvette, France, in two custom built, large capacity furnaces that have been specifically designed to minimise oxidation. The temperature steps were adapted to accommodate the characteristic loss of magnetisation at low temperatures seen in the Curie balance results and the use of half-size samples allowed secondary experiments to be carried out where necessary. The strict PICRIT-03 selection criteria were rigorously applied to the data and a high success rate of 53% has been achieved on a sample level. The flow averaged results almost double the existing 14C-dated palaeointensity dataset for this time window and confirm a period of high intensity over the past 4 kyr preceded by a period in which the dipole moment was weaker. However, the values attained in this study are on average higher than previously published data; reliability of these values is discussed.

  6. Dating of the humin fraction of soil organic matter and its comparison with 14 C ages of fossil charcoal

    International Nuclear Information System (INIS)

    Gouveia, Susy Eli Marques; Pessenda, Luiz Carlos Ruiz; Aravena, Ramon

    1999-01-01

    The radiocarbon dating of the organic matter (SOM) is a polemic subject, due mainly to the complexity of the formation of the soils and to the variable contamination from several sources. Soil samples from 4 different Brazilian localities were submitted to physical and chemical pre-treatment for the extraction of humin fraction, which is the most stable organic compound and theoretically the oldest and representative of the age of the SOM. The radiocarbon dating obtained from the total SOM and their humin fractions are compared to the 14 C ages from buried charcoals at similar depths. The radiocarbon ages obtained from such charcoals are, in most of the cases, concordant within the experimental errors of those obtained on humin fractions, or are in average 10% higher, with one exception. Thus, the ages on humin fractions could be assumed as the minimum ages for the associated soils, while the results obtained on total SOM, even at depths until 200 cm, exhibit pronounced contamination effect by modern carbon, rejuvenating their ages. (author)

  7. Design of a hybrid gas proportional counter with CdTe guard counters for 14C dating system

    International Nuclear Information System (INIS)

    Zhang, L.; Takahashi, H.; Hinamoto, N.; Nakazawa, M.; Yoshida, K.

    2002-01-01

    Nowadays uniform, low-cost and large-size compound semiconductor detectors are available up to several square centimeters. We are trying to combine this technology with conventional gas detectors to upgrade an anticoincidence type proportional counter, Oeschger-type thin wall counter of 2.2 l, used for a 14 C dating facility at the University of Tokyo. In order to increase the ratio of the signal to the background for smaller quantity of samples less than 1 g, an effective approach is to minimize the detector volume at higher gas pressure. However, the anticoincidence function suffers from such a small volume. Therefore we designed a new active wall gas counter of 0.13 l counting volume using CdTe compound semiconductor detectors as the wall of the gas proportional counter to perform anticoincidence. Simulation study showed that at noise thresholds less than 70 keV, the wall counters can reject above 99.8% of events arising from outer gamma rays. Measured noise levels of CdTe detectors were smaller than 24 keV which is low enough for 99.8% anticoincidence efficiency. The experiment showed an anticoincidence efficiency for outer gamma rays from 70% to 80%, similar to that of the old 14 C counter. The lost anticoincidence efficiency results from the area of 21.74% which was not covered with CdTe due to two holes for the path of the center anode wire and slots between every two sides of CdTe detectors

  8. 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.

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

    Science.gov (United States)

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

    2017-09-01

    The vast majority of radiocarbon measurement results (14C/12C isotopic ratios or sample activities) are corrected for isotopic fractionation processes (measured as 13C/12C isotopic ratios) that occur in nature, in sample preparation and measurement. In 1954 Harmon Craig suggested a value of 2.0 for the fractionation ratio b that is used to correct 14C/12C ratios for shifts in the 13C/12C ratios and this value has been applied by the radiocarbon community ever since. While theoretical considerations suggest moderate deviations of b from 2.0, some measurements have suggested larger differences (e.g. b = 2.3, measured by Saliège and Fontes in 1984). With the high precision attained in radiocarbon measurements today (±2‰), even a relatively small deviation of b from 2.0 can impact the accuracy of radiocarbon data, and it is, therefore, of interest to re-evaluate the fractionation corrections. In the present study, the fractionation ratio b was determined by independent experiments on the chemical reduction of carbon dioxide (CO2) to elemental carbon (graphitization reaction) and on the photosynthetic uptake of CO2 by C3 and C4 plants. The results yielded b = 1.882 ± 0.019 for the reduction of CO2 to solid graphite and b = 1.953 ± 0.025 for the weighted mean of measurements involving C3 and C4 photosynthesis pathways. In addition, the analysis of over 9600 full-sized OX-I and OX-II normalizing standards measured between 2002 and 2012 confirms b values lower than 2.0. The obtained values are in good agreement with quantum mechanical estimates of the equilibrium fractionation and classic kinetic fractionation as well as with results from other light three-isotope systems (oxygen, magnesium, silicon and sulfur). While the value of the fractionation ratio varies with the relative importance of kinetic and equilibrium fractionation, the values obtained in the present study cluster around b = 1.9. Our findings suggest that a significant fraction of all samples

  10. High-precision measurements of 14C as a circulation tracer in the Pacific, Indian, and Southern Oceans with Accelerator Mass Spectrometry (AMS)

    International Nuclear Information System (INIS)

    Reden, Karl F. von; Peden, John C.; Schneider, Robert J.; Bellino, Mary; Donoghue, Joanne; Elder, Kathryn L.; Gagnon, Alan R.; Long, Patricia; McNichol, Ann P.; Morin, Tracey; Stuart, Dana; Hayes, John M.; Key, Robert M.

    1999-01-01

    The National Ocean Sciences Accelerator Mass Spectrometry Facility (NOSAMS) has completed the carbon isotope analysis of a major fraction of the 13,500 sea water samples collected in the framework of the World Ocean Circulation Experiment (WOCE) from three of the major world oceans between 1991 and 1996. We will describe the AMS technique employed at NOSAMS and, using 3-D data visualization techniques we will demonstrate the present status of the data set and offer some preliminary conclusions about the distribution of natural and anthropogenic 14 C in the oceans. In particular, we will be able to compare some of the data with results from the Geochemical Ocean Sections Study (GEOSECS, 1972-1978) to obtain information about the time dependence of oceanic circulation processes, tracing the 14 C signal introduced into the oceans during the atmospheric nuclear bomb tests in the 1950's and 1960's

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

    Science.gov (United States)

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

    2007-06-01

    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 14C can be measured using Accelerator Mass Spectrometry (AMS), a goat model was used to establish a minimum oral dose of 14C-labeled PCB (2,2‧,4,4‧,5,5‧-hexachlorobiphenyl-UL-14C) 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 14C 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Janle, E. [Purdue University, Department of Foods and Nutrition, 700 West State Street, West Lafayette, IN 47907-2059 (United States)]. E-mail: janle@purdue.edu; Sojka, J. [Veterinary Clinical Sciences, Purdue University, West Lafayette, IN (United States); Jackson, G.S. [Department of Physics, Purdue University, West Lafayette, IN (United States); Lachcik, P. [Purdue University, Department of Foods and Nutrition, 700 West State Street, West Lafayette, IN 47907-2059 (United States); Einstien, J.A. [Department of Physics, Purdue University, West Lafayette, IN (United States); Santerre, C.R. [Purdue University, Department of Foods and Nutrition, 700 West State Street, West Lafayette, IN 47907-2059 (United States)

    2007-06-15

    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 {sup 14}C can be measured using Accelerator Mass Spectrometry (AMS), a goat model was used to establish a minimum oral dose of {sup 14}C-labeled PCB (2,2',4,4',5,5'-hexachlorobiphenyl-UL-{sup 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 {mu}g PCB/kg bw) was administered. Plasma and milk samples were collected for 2 months after dosing. The concentration of {sup 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.

  13. 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

  14. 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.

  15. AMS-{sup 14}C measurements for the carbonate platform of the offshore Campos Basin, Rio de Janeiro State, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Coimbra, Melayne M. E-mail: melayne@onda.com.br; Barbosa, Catia F.; Soares-Gomes, Abilio; Silva, Cleverson G.; Rios-Netto, Aristoteles; Mueller, Ken A

    2000-10-01

    As part of our accelerator mass spectrometry (AMS) program in Brazil we prepared and measured some red algae carbonate crust samples from Campos Basin, Rio de Janeiro, Brazil. The measurements were performed at Purdue Rare Isotope Measurement Laboratory (PRIME Lab), Purdue University, IN, USA. This carbonate material is interlaminated with foraminiferal lime mud reflecting recurrent intervals of carbonate development, which might be linked to outer-shelf oceanographic circulation.

  16. Dynamics of 14C-labeled glucose and ammonium in saline arable soils Dinâmica de glicose marcada com 14C e amônio em solos salinos

    Directory of Open Access Journals (Sweden)

    Alma Vuelvas-Solórzano

    2009-08-01

    Full Text Available Organic matter dynamics and nutrient availability in saline agricultural soils of the State of Guanajuato might provide information for remediation strategies. 14C labeled glucose with or without 200 mg kg-1 of NH4+-N soil was added to two clayey agricultural soils with different electrolytic conductivity (EC, i.e. 0.94 dS m-1 (low EC; LEC and 6.72 dS m-1 (high EC; HEC, to investigate the effect of N availability and salt content on organic material decomposition. Inorganic N dynamics and production of CO2 and 14CO2 were monitored. Approximately 60 % of the glucose-14C added to LEC soil evolved as 14CO2, but only 20 % in HEC soil after the incubation period of 21 days. After one day, 500 mg 14C from HEC soil. No N mineralization occurred in the LEC and HEC soils and glucose addition reduced the concentrations of inorganic N in unamended soil and soil amended with NH4+-N. The NO2- and NO3- concentrations were on average higher in LEC than in HEC soil, with exception of NO2- in HEC amended with NH4+-N. It was concluded that increases in soil EC reduced mineralization of the easily decomposable C substrate and resulted in N-depleted soil.Os conhecimentos sobre a dinâmica da matéria orgânica e disponibilidade de nutrientes em solos salinos podem ser úteis para nortear a adoção de estratégias de recuperação e manejo. O objetivo deste trabalho foi avaliar o efeito da condutividade elétrica (EC e presença de N inorgânico na decomposição da matéria orgânica a dois solos salinos localizados em Guanajuato (México. Nesse sentido, glicose marcada com 14C com ou sem amônio na dose de 200 mg kg-1 de N foi adicionada em dois tipos de solo com valores de condutividade elétrica de 0,94 dS m-1 (baixo EC; LEC e 6,72 dS m-1 (alta EC; HEC. Amostras de solos foram incubadas durante 21 dias e, ao longo desse tempo, foram avaliadas as concentrações de N inorgânico e a produção de 12CO2 e 14CO2. Após o período de incubação, aproximadamente 60

  17. A numerical approach to 14C wiggle-match dating of organic deposits: best fits and confidence intervals

    NARCIS (Netherlands)

    Blaauw, M.; Heuvelink, G.B.M.; Mauquoy, D.; Plicht, van der J.; Geel, van B.

    2003-01-01

    C-14 wiggle-match dating (WMD) of peat deposits uses the non-linear relationship between C-14 age and calendar age to match the shape of a sequence of closely spaced peat C-14 dates with the C-14 calibration curve. A numerical approach to WMD enables the quantitative assessment of various possible

  18. Dating of the humin fraction of soil organic matter and its comparison with {sup 14} C ages of fossil charcoal; Datacao da fracao humina da materia organica do solo e sua comparacao com idades {sup 14} C de carvoes fosseis

    Energy Technology Data Exchange (ETDEWEB)

    Gouveia, Susy Eli Marques; Pessenda, Luiz Carlos Ruiz [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil); Aravena, Ramon [Waterloo Univ., ON (Canada)

    1999-12-01

    The radiocarbon dating of the organic matter (SOM) is a polemic subject, due mainly to the complexity of the formation of the soils and to the variable contamination from several sources. Soil samples from 4 different Brazilian localities were submitted to physical and chemical pre-treatment for the extraction of humin fraction, which is the most stable organic compound and theoretically the oldest and representative of the age of the SOM. The radiocarbon dating obtained from the total SOM and their humin fractions are compared to the {sup 14} C ages from buried charcoals at similar depths. The radiocarbon ages obtained from such charcoals are, in most of the cases, concordant within the experimental errors of those obtained on humin fractions, or are in average 10% higher, with one exception. Thus, the ages on humin fractions could be assumed as the minimum ages for the associated soils, while the results obtained on total SOM, even at depths until 200 cm, exhibit pronounced contamination effect by modern carbon, rejuvenating their ages. (author)

  19. Do 14C dates always turn into an absolute chronology? The case of the Middle Neolithic in western Lesser Poland

    Directory of Open Access Journals (Sweden)

    Marek Nowak

    2018-01-01

    Full Text Available In the late 5th, 4th, and early 3rd millennia BC, different archaeological units are visible in western Lesser Poland. According to traditional views, local branches of the late Lengyel-Polgár complex, the Funnel Beaker culture, and the Baden phenomena overlap chronologically in great measure. The results of investigations done with new radiocarbon dating show that in some cases a discrete mode and linearity of cultural transformation is recommended. The study demonstrates that extreme approaches in which we either approve only those dates which fit with our concepts or accept with no reservation all dates as such are incorrect.

  20. {sup 14}C dating and stable carbon isotopes of soil organic matter in the Southeastern region of Sao Paulo State; e

    Energy Technology Data Exchange (ETDEWEB)

    Mofatto, Milene; Pessenda, Luiz Carlos Ruiz; Bendassoli, Jose Albertino; Leite, Acacio Zuniga [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil)]. E-mail: mofatto@cena.usp.br; pessenda@cena.usp.br; Oliveira, Paulo de Oliveira [Universidade de Guarulhos, SP (Brazil)]. E-mail: paulo@bjd.com.br; Garcia, Ricardo Jose Francischetti [Herbario da Prefeitura Municipal de Sao Paulo, SP (Brazil)]. E-mail: rjfgarcia@estadao.com.br

    2005-07-01

    The objective of this research is to characterize the isotopic composition ({sup 13}C, {sup 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 ({delta}{sup 13}C) of SOM will be used as an indicator of vegetation types from the local ecosystems and {sup 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{sub 3} plant predominant and/or a mixture of C{sub 3} and C{sub 4}. (author)

  1. 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

  2. 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

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

    Science.gov (United States)

    Crema, Enrico R; Habu, Junko; Kobayashi, Kenichi; Madella, Marco

    2016-01-01

    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.

  4. 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.

  5. {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)

  6. The last glaciation of Bear Peninsula, central Amundsen Sea Embayment of Antarctica: Constraints on timing and duration revealed by in situ cosmogenic 14C and 10Be dating

    Science.gov (United States)

    Johnson, Joanne S.; Smith, James A.; Schaefer, Joerg M.; Young, Nicolás E.; Goehring, Brent M.; Hillenbrand, Claus-Dieter; Lamp, Jennifer L.; Finkel, Robert C.; Gohl, Karsten

    2017-12-01

    Ice streams in the Pine Island-Thwaites region of West Antarctica currently dominate contributions to sea level rise from the Antarctic ice sheet. Predictions of future ice-mass loss from this area rely on physical models that are validated with geological constraints on past extent, thickness and timing of ice cover. However, terrestrial records of ice sheet history from the region remain sparse, resulting in significant model uncertainties. We report glacial-geological evidence for the duration and timing of the last glaciation of Hunt Bluff, in the central Amundsen Sea Embayment. A multi-nuclide approach was used, measuring cosmogenic 10Be and in situ14C in bedrock surfaces and a perched erratic cobble. Bedrock 10Be ages (118-144 ka) reflect multiple periods of exposure and ice-cover, not continuous exposure since the last interglacial as had previously been hypothesized. In situ14C dating suggests that the last glaciation of Hunt Bluff did not start until 21.1 ± 5.8 ka - probably during the Last Glacial Maximum - and finished by 9.6 ± 0.9 ka, at the same time as ice sheet retreat from the continental shelf was complete. Thickening of ice at Hunt Bluff most likely post-dated the maximum extent of grounded ice on the outer continental shelf. Flow re-organisation provides a possible explanation for this, with the date for onset of ice-cover at Hunt Bluff providing a minimum age for the timing of convergence of the Dotson and Getz tributaries to form a single palaeo-ice stream. This is the first time that timing of onset of ice cover has been constrained in the Amundsen Sea Embayment.

  7. 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

  8. Evolution of groundwater chemistry in coastal aquifers of the south-eastern White Sea area (NW Russia) using14C and234U-238U dating.

    Science.gov (United States)

    Malov, A I

    2018-03-01

    The specific objectives of the study are to clarify the sources and characteristics of groundwater in the aquifers along the coast of the White Sea in northwestern Russia, and on this basis to perform a broad 14 C and 234 U/ 238 U dating of all their types, taking into account the mixing processes. Investigation of an evolution of the groundwater chemistry revealed that the main evolutionary trends are the following: (1) Mixing Late Pleistocene brackish water end member (brackish1) and Mikulino seawater end member with strongly brackish and salty water in the Vpd aquifer (salty Vpd) formation. Groundwater dating showed the "brackish1" residence time in the aquifer of 32.96±2.3ka. Recharge of "brackish1" could have occurred in MIS 3. (2) Mixing Late Pleistocene freshwater end member (fresh LP) and "salty Vpd" end member with brackish water (brackish2) formation. Groundwater dating showed the "brackish2" residence time in the aquifer from 25.1±0.7 to 39.2±6.3ka. Recharge of "fresh LP" could have occurred ~ in MIS 3 also. (3) Mixing Middle Pleistocene-Holocene freshwater of melting glaciers (fresh MP-H) end member and brine end member with the strongly brackish and salty water in Vmz aquifer (salty Vmz) formation. Recharge of "fresh MP-H" could have occurred in Middle Pleistocene-Holocene during MIS 12-MIS 1. As a result of intensive and rapid recharge after the glacial melting, glacial fluids have penetrated at depth to >200m. The results of this study provide a better understanding of the interrelationship of various groundwater flows near the coasts and contribute to a more justified and efficient use of them for drinking water supply in large cities, balneological treatment and industrial extraction of iodine waters. They also allow assessment of the risks of dumping saline drainage water into the environment. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Retrospective study of {sup 14}C concentration in the vicinity of NPP Jaslovské Bohunice using tree rings and the AMS technique

    Energy Technology Data Exchange (ETDEWEB)

    Ješkovský, Miroslav [CENTA Laboratory, Faculty of Mathematics, Physics and Informatics, Comenius University, 84248 Bratislava (Slovakia); Povinec, Pavel P., E-mail: Povinec@fmph.uniba.sk [CENTA Laboratory, Faculty of Mathematics, Physics and Informatics, Comenius University, 84248 Bratislava (Slovakia); Steier, Peter [VERA Laboratory, Faculty of Physics, University of Vienna, 1090 Vienna (Austria); Šivo, Alexander; Richtáriková, Marta [CENTA Laboratory, Faculty of Mathematics, Physics and Informatics, Comenius University, 84248 Bratislava (Slovakia); Golser, Robin [VERA Laboratory, Faculty of Physics, University of Vienna, 1090 Vienna (Austria)

    2015-10-15

    Atmospheric radiocarbon has been monitored around the Nuclear Power Plant (NPP) Jaslovské Bohunice (Slovakia) using CO{sub 2} absorption in NaOH solution since 1969. In 2012, tree ring samples were collected from Tilia cordata using an increment borer at Žlkovce monitoring station situated close to the Bohunice NPP. Each tree ring was identified and graphite targets were produced for {sup 14}C analysis by accelerator mass spectrometry. The {sup 14}C concentrations obtained from the tree-ring samples have been in a reasonable agreement with the averaged annual {sup 14}C concentrations in atmospheric CO{sub 2}.

  10. 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.

  11. Dating bog bodies by means of C-14-AMS

    NARCIS (Netherlands)

    van der Plicht, J; van der Sanden, WAB; Aerts, AT; Streurman, HJ

    We have made efforts to date a substantial number of bodies from northwest European peat bogs by means of C-14. In our research, we compared materials such as skin, hair, bone, textile, leather and wood where available. Most of the bodies we investigated were found to date from the Late Iron

  12. 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

  13. The new extended HVE 1 MV multi-element AMS system for low background installed at the Aarhus AMS Dating Centre

    Energy Technology Data Exchange (ETDEWEB)

    Heinemeier, Jan; Olsen, Jesper [AMS " 1" 4C Dating Centre, Department of Physics and Astronomy, Aarhus University, Aarhus (Denmark); Klein, Matthias; Mous, Dirk [High Voltage Engineering Europa B.V., Amersfoort (Netherlands)

    2015-10-15

    Aarhus University, Department of Physics and Astronomy has installed a new multi-element AMS system at its AMS {sup 14}C Dating Centre. It is manufactured by High Voltage Engineering Europa B.V. and based on a 1 MV Tandetron accelerator with a dual gas system (Ar and He) for the terminal stripper. The injector is equipped with two independently operating ion sources and a 120 degree bouncer magnet with high resolution and a bending power of 340 amu at 35 keV, supporting the measurements of actinides. The high-energy (HE) spectrometer features a degrader foil for isobar suppression and a second HE magnet for suppression of ions scattered in the HE ESA, which ensures very low detection limits. The control system supports different methods for isotope switching: “traditional” fast bouncing, adjusting the Hall-probe controlled magnet fields (for, e.g., {sup 3}H), or changing the complete set of operation parameters (e.g., for actinides). During the on-site acceptance tests, the following background levels were measured: <10{sup −16} for tritium, <10{sup −15} for {sup 14}C, <10{sup −15} for {sup 10}Be (down to <10{sup −16} in a later 3 h run), 2 × 10{sup −15} for {sup 26}Al, 2 × 10{sup −13} for {sup 129}I and 9 × 10{sup −12} for {sup 41}Ca and for {sup 239}Pu ({sup 240}Pu) a 1.5 (0.5) pg per mg iron, which demonstrates the multi-element capability of the system.

  14. 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)

  15. 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.

  16. 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.)

  17. A multi-isotope (B, Sr, O, H) and age dating (3H-3He, 14C) study of groundwater from Salinas Valley, California

    International Nuclear Information System (INIS)

    Vengosh, A.; Gill, J.; Davisson, M.L.; Hudson, G.B.

    1999-01-01

    This study investigates the chemical and isotopic compositions of groundwater from Salinas Valley, California in order to constrain the origin and rates of groundwater contamination. We use an array of geochemical, environmental isotopes of water ( 18 O/ 16 O, D/H, 3 H- 3 He) and dissolved salts ( 11 B/ 10 B, 87 Sr/ 86 Sr, 14 C) to establish a reliable conceptual model for the basin. The basin consists of a deep, confined '400-foot aquifer' overlying the '180-foot aquifer' and a perched aquifer, all made up of sand, gravels, clays, and alluvial deposits. Our 3 H- 3 He, 14 C, and δ 18 O results show different replenishment zones and rates in the basin: (1) rapid replenishment ( 14 C concentrations of 72 to 98 pmc) in the perched and 180-foot aquifers in the northern area; (2) fast arrival (15 years) of 18 O- and NO 3 -enriched agriculture-return flows in the unconfined 180-foot aquifer in the central valley; (3) young water recharge (6 to 20 years) fi-om the Salinas River, which is enriched in 18 O and D relative to GMWL, occurs in the southern basin; and (4) travel time of >10,000 years ( 14 C = 21.3 PMC) in the deep 400-foot aquifer in the northern area of the valley, indicating pristine slow recharge. We identified several different end-member saline components with distinguishable chemical and isotopic fingerprints: (1) agriculture return flow in the perched aquifer (e.g., high NO 3 and SO 4 , low 87 Sr/ 86 Sr 0.7082, δ 11 B = 19 per mille); (2) salt-water intrusion in the northern basin (e.g., low Na/Cl, marine Br/Cl, high Ca/Mg, δ 11 B = 17 to 38 per mille, 87 Sr/ 86 Sr = 0.7088 to 0.7096; (3) non-marine saline water in the southern part of the valley (e.g., high SO 4 , high Na/Cl, δ 11 B = 24 to 30 per mille, 87 Sr/ 86 Sr = 0.70852). The geochemical and isotopic fingerprints of the different water sources enables us to delineate the impact of these sources in different areas of the valley as well as to evaluate the origin of the saline, Sod-enriched plume

  18. AMS-dated mollusks in beach ridges and berms document Holocene sea-level and coastal changes in northeastern Kuwait Bay

    Science.gov (United States)

    Reinink-Smith, Linda M.

    2015-09-01

    In northeastern Kuwait, ancient beach ridges and associated berms are separated from the present shoreline by a 4-6 km-wide sabkha. A diverse mollusk fauna in the beach ridges attests to a former open marine environment. A total of 21 AMS dates were obtained in this study. Thirteen mollusk samples from beach ridges yielded AMS dates ranging from ~ 6990 cal yr BP in the southeast to ~ 3370 cal yr BP in the northwest, suggesting a southeast to northwest age progression during the Holocene transgression. In contrast, four samples from berms throughout the study area yielded AMS dates of 5195-3350 cal yr BP showing no age progression; these berms consist largely of Conomurex persicus gastropods that aggregated by storms during a highstand at ~ 5000-3500 cal yr BP. The berms are presently at ~ + 6 m above sea level, 2-3 m above the beach ridges. Human settlements were common on the ridge crests before and after the highstand. Regression to present-day sea level commenced after the highstand, which is when the sabkha began forming. A landward, marine-built terrace, which yielded AMS dates > 43,500 14C yr BP, probably formed during Marine Oxygen Isotope Stage 5e and hence is not genetically related to the beach ridges.

  19. 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.

  20. Dry extraction of 14C02 and 14C0 from Antarctic ice

    NARCIS (Netherlands)

    Roijen, J.J. van; Bintanja, R.; Borg, R. van den; Broeke, M.R. van den; Jong, A.F.M. de; Oerlemans, J.

    A dry extraction method was used to obtain trapped CO, of 2-5 kg ice samples from a blue ice zone in East Antarctica. In situ produced 14C was also extracted in 14C0, and 14C0 concentrations at a ratio of 3.4 f 0.9. Correction of trapped 14C0, from in situ resulted in ice dates in the range 5-15

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. Datação da fração humina da matéria orgânica do solo e sua comparação com idades 14C de carvões fósseis Dating of the humin fraction of soil organic matter and its comparison with 14C ages of fossil charcoal

    Directory of Open Access Journals (Sweden)

    Susy Eli Marques Gouveia

    1999-12-01

    Full Text Available The radiocarbon dating of the soil organic matter (SOM is a polemic subject, due mainly to the complexity of the formation of the soils and to the variable contamination from several sources. Soil samples from 4 different Brazilian localities were submitted to physical and chemical pre-treatment for the extraction of humin fraction, which is the most stable organic compound and theoretically the oldest and representative of the age of the SOM. The radiocarbon dating obtained from the total SOM and their humin fractions are compared to the 14C ages from buried charcoals at similar depths. The radiocarbon ages obtained from such charcoals are, in most of the cases, concordant within the experimental errors of those obtained on humin fractions, or are in average 10% higher, with one exception. Thus, the ages on humin fractions could be assumed as the minimum ages for the associated soils, while the results obtained on total SOM, even at depths until 200 cm, exhibit pronounced contamination effect by modern carbon, rejuvenating their ages.

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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)

  13. 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

  14. Posterior archaeomagnetic dating for the early Medieval site Thunau am Kamp, Austria

    Science.gov (United States)

    Schnepp, Elisabeth; Lanos, Philippe; Obenaus, Martin

    2014-05-01

    The early medieval site Thunau am Kamp consists of a hill fort and a settlement with large burial ground at the bank of river Kamp. All these features are under archaeological investigation since many years. The settlement comprises many pit houses, some with stratigraphic order. Every pit house was equipped with at least one cupola oven and/or a hearth or fireplace. Sometimes the entire cupola was preserved. The site was occupied during the 9th and 10th AD according to potshards which seem to indicate two phases: In the older phase ovens were placed in the corner of the houses while during the younger phase they are found in the middle of the wall. In order to increase the archaeomagnetic data base 14 ovens have been sampled. They fill the temporal gap in the data base for Austria around 900 AD. Laboratory treatment included alternation field and thermal demagnetisations as well as rock magnetic experiments. The baked clay with was formed from a loess sediment has preserved stable directions. Apart from one exception the mean characteristic remanent magnetization directions are concentrated around 900 AD on the early medieval part of the directional archaeomagnetic reference curve of Austria (Schnepp & Lanos, GJI, 2006). Using this curve archaeomagnetic dating with RenDate provides ages between 800 and 1100 AD which are in agreement with archaeological dating. In one case archaeomagnetic dating is even more precise. Together with the archaeological age estimates and stratigraphic information the new data have been included into the database of the Austrian curve. It has been recalculated using a new version of RenCurve. The new data confine the curve and its error band considerably in the time interval 800 to 1100 AD. The curve calibration process also provides a probability density distribution for each structure which allows for posterior dating. This refines temporal errors considerably. Usefulness of such an approach and archaeological implications will be

  15. 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.

  16. 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.

  17. 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.

  18. Life history of the individuals buried in the St. Benedict Cemetery (Prague, 15th-18th centuries): insights from (14)C dating and stable isotope (δ(13)C, δ(15)N, δ(18)O) analysis.

    Science.gov (United States)

    Salesse, Kevin; Dufour, Élise; Castex, Dominique; Velemínský, Petr; Santos, Frédéric; Kuchařová, Hedvika; Jun, Libor; Brůžek, Jaroslav

    2013-06-01

    Funerary practices and bioarchaeological (sex and age) data suggest that a mortality crisis linked to an epidemic episode occurred during the fifth phase of the St. Benedict cemetery in Prague (Czech Republic). To identify this mass mortality episode, we reconstructed individual life histories (dietary and mobility factors), assessed the population's biological homogeneity, and proposed a new chronology through stable isotope analysis (δ(13)C, δ(18)O and δ(15)N) and direct radiocarbon dating. Stable isotope analysis was conducted on the bone and tooth enamel (collagen and carbonate) of 19 individuals from three multiple graves (MG) and 12 individuals from individual graves (IG). The δ(15)N values of collagen and the difference between the δ(13)C values of collagen and bone carbonate could indicate that the IG individuals had a richer protein diet than the MG individuals or different food resources. The human bone and enamel carbonate and δ(18)O values suggest that the majority of individuals from MG and all individuals from IG spent most of their lives outside of the Bohemian region. Variations in δ(18)O values also indicate that all individuals experienced residential mobility during their lives. The stable isotope results, biological (age and sex) data and eight (14)C dates clearly differentiate the MG and IG groups. The present work provides evidence for the reuse of the St. Benedict cemetery to bury soldiers despite the funeral protest ban (1635 AD). The Siege of Prague (1742 AD) by French-Bavarian-Saxon armies is identified as the cause of the St. Benedict mass mortality event. Copyright © 2013 Wiley Periodicals, Inc.

  19. 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.

  20. 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

  1. 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.

  2. The sharp rise of DELTA-14C ca. 800 cal BC: possible causes, related climatic connections and the impact on human environments

    NARCIS (Netherlands)

    Geel, Bas van; Plicht, Johannes van der; Kilian, M.R.; Klaver, E.R.; Kouwenberg, J.H.M.; Renssen, H.; Reynaud-Farrera, I.; Waterbolk, H.T.

    1998-01-01

    In this study we report on accelerator mass spectrometry (AMS) wiggle-match dating of selected macrofossils from organic deposits ca. 800 cal BC (ca. 2650 BP). Based on paleological, archaeological and geological evidence, we found that the sharp rise of atmospheric 14C between 850 and 760 cal BC

  3. 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).

  4. 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.

  5. 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.

  6. Datação da fração humina da matéria orgânica do solo e sua comparação com idades 14C de carvões fósseis Dating of the humin fraction of soil organic matter and its comparison with 14C ages of fossil charcoal

    OpenAIRE

    Susy Eli Marques Gouveia; Luiz Carlos Ruiz Pessenda; Ramon Aravena

    1999-01-01

    The radiocarbon dating of the soil organic matter (SOM) is a polemic subject, due mainly to the complexity of the formation of the soils and to the variable contamination from several sources. Soil samples from 4 different Brazilian localities were submitted to physical and chemical pre-treatment for the extraction of humin fraction, which is the most stable organic compound and theoretically the oldest and representative of the age of the SOM. The radiocarbon dating obtained from the total S...

  7. 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

  8. Synthesis of [14C] alaproclate

    International Nuclear Information System (INIS)

    Gawell, Lars

    1986-01-01

    The synthesis of carbon-14 labelled alaproclate from [2- 14 C]acetone in three steps is described. The label is introduced by the reaction of a benzylic Grignard reagent with the ketone yielding a tertiary alcohol. Subsequent esterification with an α-bromocarboxylic acid chloride and amination produced the title compound in a 13% overall radiochemical yield. (author)

  9. {sup 14}C in human diet in three Spanish locations; {sup 14}C en dieta humana en tres localizaciones espanolas

    Energy Technology Data Exchange (ETDEWEB)

    Gomez Martinez, I.; Santos Arevalo, F. J.; Manjon, G.; Garcia-Tenorio, R.

    2011-07-01

    {sup 14}C reach humans via the diet. In this study we present the results of diet samples from three locations type Spanish, Seville, Caceres and Tenerife. These diets are collected quarterly and historical dates back to early 2008.

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.)

  16. 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.

  17. 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%

  18. 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.

  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

    ... 41 Public Contracts and Property Management 4 2010-07-01 2010-07-01 false Am I required to record departure/arrival dates and times on my travel claim? 301-11.10 Section 301-11.10 Public Contracts and... TRAVEL EXPENSES 11-PER DIEM EXPENSES General Rules § 301-11.10 Am I required to record departure/arrival...

  20. 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

  1. 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

  2. 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

  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. 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

  6. 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

  7. 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)

  8. 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.

  9. 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.

  10. 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.

  11. 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)

  12. 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

  13. Study of the reaction {sup 14} C (p,p) {sup 14} C; Estudio de la reaccion {sup 14} C (p,p) {sup 14} C

    Energy Technology Data Exchange (ETDEWEB)

    Murillo, G.; Ramirez, J.; Avila, O.; Fernandez, M. [ININ, A.P. 18-1027, Mexico D.F. (Mexico); Darden, S.E.; Prior, R.P.; Sen, S. [University of Notre Dame, Indiana (United States)

    1991-04-15

    The study of the elastic scattering of polarized protons in {sup 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 {sup 14} C, it give us experimental information of the excited states in {sup 15} N. The study of these states, is since of considerable interest it is not very easy to obtain a target of {sup 14} C also in a reaction {sup 14} C (p,p) {sup 14} C is possible to obtain information of levels in {sup 15} N to an excitation energy E{sub X} >14.95 MeV. (Author)

  14. Activity concentration measurements of 14C in the surroundings of two Swedish nuclear power plants

    International Nuclear Information System (INIS)

    Erlandsson, B.; Hellborg, R.; Stenstroem, K.; Mattsson, S.

    1999-01-01

    In the nature 14 C is continuously produced by cosmic ray bombardment of 13 N in the stratosphere. 14 C is also produced in nuclear reactors and part of it is released to the atmosphere in the form of CO 2 . Because of the biological importance of carbon and the long half-life of 14 C it is of interest to measure the releases and to follow their incorporation in living material. Around Forsmark nuclear power plant we have collected sallow leaves and pine tree rings and found an excess of 14 C up to 25 ± 5 Bq/kg C. The 14 C activity concentration, 0-4 Bq/kg C in annual tree rings around Barsebaeck nuclear power plant as well as the background 14 C activity levels from two reference sites in southern Sweden during 1973-1997 have been measured. Accelerator mass spectrometry (AMS), as well as decay counting have been used in this investigation. (au)

  15. 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)

  16. 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)

  17. 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

  18. 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

  19. 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

  20. 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

  1. 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

  2. Synthesis of 14C-labeling omethoate

    International Nuclear Information System (INIS)

    She Dongmei; Qu Zhe; Huang Qiliang; Li Fenmin

    2006-01-01

    14 C-Omethoate [O,O-dimethyl-S-(N-methyl carbamoyl-methyl)phosphorothioate] was synthesized by four steps. The radio-chemical yield was 27.81%. TLC analysis of the final product showed the radiochemical purity is higher than 95%. (authors)

  3. 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.

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

    African Journals Online (AJOL)

    ADMIN

    night periods. The most abundant metabolite was [14C]GA19 (10% of the activity in the samples). Key words/phrases: Conjugation, ecotype, gibberellins, metabolism, radioactivity. Abbreviations: [14C]GAx, radioactive carbon labelled gibberellin x; LD, long day; SD, Short day; 1SD, one short day; 4SD, four short days; HPLC ...

  5. 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)

  6. Radionuclide dating (21Pb, 137Cs, 241Am) of recent lake sediments in a highly active geodynamic setting (Lakes Puyehue and Icalma-Chilean Lake District)

    International Nuclear Information System (INIS)

    Arnaud, F.; Magand, O.; Chapron, E.; Bertrand, S.; Boes, X.; Charlet, F.; Melieres, M.-A.

    2006-01-01

    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 ( 21 Pb) and artificial ( 137 Cs, 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 21 Pb dating

  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. 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.

  9. 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)

  10. 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.)

  11. 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)

  12. 14C-labeling of synthetic peptides

    International Nuclear Information System (INIS)

    Chersi, A.; Trinca, M.L.; Camera, M.

    1988-01-01

    Two methods are described for the labelling of synthetic peptides using iodo[ 14 C]acetic acid. The first procedure may be employed when the synthetic fragment contains a cysteine with a free sulfhydryl group. Alternatively, a commercial amino-protected cysteine may be carboxymethylated using radioactive iodoacetic acid. This derivative can be added to the growing peptide chain in the manual or automatic solid-phase synthesis of the fragment. 9 refs.; 1 figure; 1 table

  13. 14C-labeling of synthetic peptides.

    Science.gov (United States)

    Chersi, A; Trinca, M L; Camera, M

    1988-06-13

    Two methods are described for the labeling of synthetic peptides using iodo[14C]acetic acid. The first procedure may be employed when the synthetic fragment contains a cysteine with a free sulfhydryl group. Alternatively, a commercial amino-protected cysteine may be carboxymethylated using radioactive iodoacetic acid. This derivative can be added to the growing peptide chain in the manual or automatic solid-phase synthesis of the fragment.

  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. Inconsistencies between14C and short-lived radionuclides-based sediment accumulation rates: Effects of long-term remineralization.

    Science.gov (United States)

    Baskaran, M; Bianchi, T S; Filley, T R

    2017-08-01

    14 C is the most widely utilized geochronometer to investigate geological, geochemical and geophysical problems over the past 5 decades. Establishment of precise sedimentation rates is crucial for the reconstruction of paleo-climate, -ecological and - environmental studies when extrapolation of sedimentation rates is utilized for time scales beyond the dating range. However, agreement between short-term and long-term sedimentation rates in anthropogenically unperturbed sediment cores has not been shown. Here we show that the AMS 14 C-based long-term mass accumulation rate (MAR) of an organic-rich (>70%) sediment core from Mud Lake, Florida to be ∼5 times lower than the short-term MAR obtained using 239,240 Pu, 137 Cs and excess 210 Pb ( 210 Pb xs ). The measured sediment inventories of 210 Pb xs , 137 Cs and 239,240 Pu are comparable to the atmospheric fallout for the sampling site, indicating very little accelerated sediment erosion over the past several decades. Presence of sharp fallout peaks of 239,240 Pu indicates very little sediment mixing. The penetration depths of 137 Cs and 239,240 Pu were found to be much deeper than expected and this is attributed to their post-depositional mobility. MAR calculated using 14 C-ages in successive layers also indicated decreasing MARs with depth, and was reflective of progressive remineralization. Using first-order kinetics, the sediment remineralization rate was found to be 4.4 × 10 -4 y -1 and propose that over the long-term, remineralization of organic-rich sediment affected the long-term MAR, but not the ratio of 14 C/ 12 C. Thus, the MAR and linear sedimentation rate obtained using 14 C (and other isotope-based methods) could be erroneous, although 14 C ages may not be affected by such remineralization. Long-term remineralization rates of organic matter has a direct bearing on the biogeochemical cycling of elements in aqueous systems and mass balance of elements needs to be taken into consideration. Copyright

  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-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)

  18. 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

  19. 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

  20. The synthesis of HIV reverse transcriptase inhibitors [14C]L-697,661, [14C]L-697,639, [14C]L-702,007

    International Nuclear Information System (INIS)

    Wallace, M.A.; Dean, D.C.; Ellsworth, R.L.; Melilo, D.G.

    1996-01-01

    The synthesis of three carbon-14 labeled reverse transcriptase inhibitors has been accomplished by elaboration of a common intermediate, 5-ethyl-6-methyl-3-amino-2-(1H)-[4- 14 C]-pyridinone (7). Ethyl [1- 14 C]formate, prepared by esterification of sodium [ 14 C]formate, was combined with 2-pentanone under basic conditions to afford 3-[ 14 C]carboxyaldehyde-2-pentanone sodium salt (2). The pyridinone ring was constructed by condensation of 2 with nitro acetamide 4. Reduction of the nitro group afforded 5-ethyl-6-methyl-3-amino-2-(1H)-[4- 14 C]-pyridinone (7)(specific activity 54 mCi/mmol). Subsequent alkylation of 7 provided the desired reverse transcriptase inhibitors [ 14 C]L-697,661, [ 14 C]L-697,639, and [ 14 C]L-702,007. (Author)

  1. Bioconversion of alpha-[14C]zearalenol and beta-[14C]zearalenol into [14C]zearalenone by Fusarium roseum 'Gibbosum'.

    OpenAIRE

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

    1984-01-01

    Cultures of Fusarium roseium 'Gibbosum' on rice were treated with [14C]zearalenone, alpha[14C]zearalenol, or beta-[14C]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 beta-[14C]zearalenol was converted to zearalenone, and no residual b...

  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. AMS radiocarbon analysis of microsamples

    International Nuclear Information System (INIS)

    Jacobsen, G.E.; Hua, Q.; Tarchichi, J.; Fink, D.; Hotchkis, M.A.C.; Lawson, E.M.; Smith, A.M.; Tuniz, C.

    1997-01-01

    The ANTARES AMS Centre has two chemistry laboratories dedicated to preparing targets for measurement. Target preparation encompasses a variety of activities ranging from the curation of incoming samples to the numerous steps involved in the purification and processing of dissimilar samples. One of the two laboratories is set up for the physical and chemical pretreatment of 14 C samples. Treatments include cleaning by sonification, sorting, grinding and sieving, and chemical treatments such as the standard AAA treatment, and solvent extraction. Combustion and graphitisation are also carried out in this laboratory. The second laboratory is a clean room and is dedicated to the combustion, hydrolysis and graphitisation of 14 C samples as well as processing targets for the other isotopes. Combustion is achieved by heating the sample to 900 deg C in the presence of CuO, the resulting gas is purified by passing over Ag and Cu wire at 600 deg C. Graphitisation is carried out by reducing the CO 2 with an iron catalyst (600 deg C) in the presence of zinc (400 deg C) and a small amount of hydrogen. Samples such as charcoal, shell, bone, wood, sediment, seawater and groundwater, containing 0.3-1 mg or more of original carbon, are processed routinely for radiocarbon analysis. The current 14 C chemistry background for 1 mg carbon is ∼0.3 percent of modern carbon (pMC) enabling materials' dating up to 45 000 BP. The advantages and disadvantages of this method will also be discussed

  4. The synthesis of [3-14C]indirubin

    International Nuclear Information System (INIS)

    Gu Meiying; Zhang Xiuwen; Tian Shuhao

    1995-01-01

    [3- 14 C]indirubin is synthesized in three steps from potassium [ 14 C]cyanide. Firstly, Potassium [ 14 C]cyanide reacts with N,N'-diphenylthiourea to get N,N'-diphenyl [ 14 C]cyanoamidine. Then, cyclizated in the presence of anhydrous aluminium chloride and hydrolizated with hydrochloric acid, amidine is leaded to [3- 14 C]isatin. Finally, [3- 14 C]isatin is condensed with excess potassium 3-indolelate to yield [3- 14 C]indirubin in 20.34% overall radiochemical yield from K 14 CN with a specific activity of 2 GBq/mmol and a radiochemical purity of 99.9% (TLC)

  5. 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

  6. 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.)

  7. 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)

  8. 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

  9. Bioconversion of alpha-[14C]zearalenol and beta-[14C]zearalenol into [14C]zearalenone by Fusarium roseum 'Gibbosum'.

    Science.gov (United States)

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

    1984-06-01

    Cultures of Fusarium roseium 'Gibbosum' on rice were treated with [14C]zearalenone, alpha[14C]zearalenol, or beta-[14C]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 beta-[14C]zearalenol was converted to zearalenone, and no residual beta-[14C]zearalenol was detectable. Most of the alpha-[14C]zearalenol added was also converted into zearalenone with 14 days. In cultures treated with [14C]zearalenone, no radioactivity was noted in any other components.

  10. Bioconversion of. cap alpha. -(/sup 14/C)Zearalenol and. beta. -(/sup 14/C)Zearalenol into (/sup 14/C)Zearalenone by Fusarium roseum Gibbosum

    Energy Technology Data Exchange (ETDEWEB)

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

    1984-06-01

    Cultures of Fusarium roseum Gibbosum on rice were treated with (/sup 14/C)zearalenone, ..cap alpha..-(/sup 14/C)zearalenol, or ..beta..-(/sup 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 ..beta..-(/sup 14/C)zearalenol was converted to zearalenone, and no residual ..beta..-(/sup 14/C)zearalenol was detectable. Most of the ..cap alpha..-(/sup 14/C)zearalenol added was also converted into zearalenone within 14 days. In cultures treated with (/sup 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

    Energy Technology Data Exchange (ETDEWEB)

    Salehpour, Mehran, E-mail: mehran.salehpour@angstrom.uu.s [Ion Physics, Angstroem Laboratory, Department of Engineering Sciences, Box 534, Uppsala University, SE-751 21 Uppsala (Sweden); Forsgard, Niklas; Possnert, Goeran [Ion Physics, Angstroem Laboratory, Department of Engineering Sciences, Box 534, Uppsala University, SE-751 21 Uppsala (Sweden)

    2010-04-15

    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 {sup 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 {sup 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 mugC range.

  15. 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.

  16. 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).

  17. 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.

  18. 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...

  19. 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.

  20. 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

  1. Comparison of different soil organic matter fractionation methodologies: Evidences from ultrasensitive 14C measurements

    International Nuclear Information System (INIS)

    Marzaioli, Fabio; Lubritto, Carmine; Galdo, Ilaria Del; D'Onofrio, Antonio; Cotrufo, M. Francesca; Terrasi, Filippo

    2010-01-01

    Soils are studied with the aim to predict future climatic scenarios and find the best guidelines to manage terrestrial ecosystems for the mitigation of the atmospheric CO 2 rising. Carbon constituting soil organic matter (SOM) behaves as a cohort of different pools, characterized by a specific C turnover time. Both natural and anthropogenic occurring 14 C reach the soil through plant littering, becoming a valid tool to trace SOM dynamics. In this study we present a series of Accelerator Mass Spectrometry (AMS) 14 C measurements on SOM samples obtained by means of different laboratory protocols used for the isolation of soil pools from bulk soil (fractionation protocols). Radiocarbon signature of SOM fractions is used as a keyhole to look at the more effective fractionation procedure and comparison among measured 14 C on SOM fractions revealed important indications for the proposal of a novel fractionation protocol. Our data put in evidence how particle size controls the recalcitrance of ancient SOM carbon pools.

  2. 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.

  3. {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.

  4. 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.

  5. 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.

  6. 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.

  7. 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)

  8. A 150 year record of annual Bristlecone Pine 14C from the second millennium BC

    Science.gov (United States)

    Pearson, Charlotte; Salzer, Matthew; Brewer, Peter; Hodgins, Gregory; Jull, A. J. Timothy; Lange, Todd; Cruz, Richard; Brown, David; Boswijk, Gretel

    2017-04-01

    The Interdisciplinary Chronology of Civilizations Project (ICCP) at the University of Arizona (UA) aims to resolve longstanding chronological issues for Aegean and Near Eastern archaeology. A central component of this work is the production of annual resolution sequences of 14C from securely anchored tree-ring chronologies. Contemporary growth rings from Northern and Southern Hemisphere locations will be tested against a dataset of consecutive annual resolution 14C measurements from tree-rings of securely dated North American bristlecone pine (Pinus longaeva D.K. Bailey). These data will be used in a number of ways: to investigate potential issues with the current IntCal dataset due to interpolation, smoothing, or the inclusion of annual scale rapid changes in 14C; to identify 14C off-sets; to evaluate whether annual determinations of 14C present sufficient advantages for dating to justify the substantial costs involved in creating an annual resolution calibration curve; to explore whether the degree of reproducibility between species and growth locations justifies the construction of regional curves or allows us to pioneer 'annual resolution wigglematching' to anchor substantial floating tree-ring chronologies from Mediterranean archaeological contexts, and; if new rapid changes in 14C (aka 'spikes') are discovered, to use these to achieve this same goal. The initial focus of the project is the first and second millennium BC. From this period we present 150 annual 14C determinations from bristlecone pine and explore preliminary findings based on comparisons with the existing IntCal dataset, decadal data from the Mediterranean, and some contemporary years from Irish Oak (Quercus spp.) and New Zealand Kauri (Agathis australis (D. Don) Lindl.). This work, in combination with results from another UA project team (see abstract by Jull et al.) helps confirm the potential of the bristlecone pine archive for high resolution radiocarbon research.

  9. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Miyaoka, Teiji [Institute of Accelerator Analysis Ltd., 129-1 Noborito-Shinmachi, Tama-Ku Kawasaki, Kanagawa 214-0013 (Japan)]. E-mail: miyaoka@iaa-ams.co.jp; Isono, Yoshimi [Institute of Accelerator Analysis Ltd., 129-1 Noborito-Shinmachi, Tama-Ku Kawasaki, Kanagawa 214-0013 (Japan); Setani, Kaoru [Institute of Accelerator Analysis Ltd., 129-1 Noborito-Shinmachi, Tama-Ku Kawasaki, Kanagawa 214-0013 (Japan); Sakai, Kumiko [Institute of Accelerator Analysis Ltd., 129-1 Noborito-Shinmachi, Tama-Ku Kawasaki, Kanagawa 214-0013 (Japan); Yamada, Ichimaro [Mitsubishi Pharma Co., 2-2-6 Nihombashi-Honcho, Chuo-Ku, Tokyo 103-8405 (Japan); Sato, Yoshiaki [Daiichi Pure Chemicals, Co., Ltd., 2117 Muramatsu, Tokai, Naka-Gun, Ibaraki 319-1132 (Japan); Gunji, Shinobu [Daiichi Pure Chemicals, Co., Ltd., 2117 Muramatsu, Tokai, Naka-Gun, Ibaraki 319-1132 (Japan); Matsui, Takao [Institute of Accelerator Analysis Ltd., 129-1 Noborito-Shinmachi, Tama-Ku Kawasaki, Kanagawa 214-0013 (Japan)

    2007-06-15

    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 {sup 14}C-labeled drug Y-700, a novel xanthine oxidase inhibitor, of which radioactivity was about 3 MBq (85 {mu}Ci). 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 {sup 14}C-concentration in bioanalysis studies at very low radioactivity level.

  11. 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.

  12. 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.

  13. PRIME lab AMS performance, upgrades and research applications

    International Nuclear Information System (INIS)

    Sharma, P.; Bourgeois, M.; Elmore, D.; Granger, D.; Lipschutz, M.E.; Ma, X.; Miller, T.; Mueller, K.; Rickey, F.; Simms, P.; Vogt, S.

    2000-01-01

    The Purdue Rare Isotope Measurement Laboratory (PRIME Lab) is a dedicated research and service facility for AMS that provides the scientific community with timely, reliable and high quality chemical processing (∼600 samples/year) and AMS measurements (∼3000 samples/year) of 10 Be, 14 C, 26 Al, 36 Cl, 41 Ca and 129 I. The AMS system is based on an upgraded FN (7 MV) tandem accelerator that has recently been modified to improve performance. The precision is 1% for 14 C and it is 3-5% for the other nuclides for radioisotope/stable isotope ratios at the 10 -12 levels. System background for 10 Be, 14 C, 26 Al, 36 Cl and 41 Ca is 1-10x10 -15 while for 129 I the natural abundance limits it to 20x10 -15 . Research is being carried out in Earth, planetary, and biomedical sciences. Geoscience applications include determination of exposure ages of glacial moraines, volcanic eruptions, river terraces, and fault scarps. Burial histories of sand are being determined to decipher the timing of human expansion and climatic history. Environmental applications are tracing the release of radioactivity from nuclear fuel reprocessing plants, water tracing, and neutron dosimetry. The applications using meteoric nuclides are oil field brines, sediment subduction, radiocarbon dating, and groundwater 36 Cl mapping. Radionuclide concentrations are also determined in meteorites and tektites for deciphering space and terrestrial exposure histories

  14. 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

  15. 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%).

  16. 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

  17. 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 .

  18. 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}.

  19. 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.)

  20. 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 ...

  1. Bound sup 14 C residues in stored wheat treated with ( sup 14 C)deltamethrin and their bioavailability in rats

    Energy Technology Data Exchange (ETDEWEB)

    Khan, S.U.; Kacew, S. (Agriculture Canada, Ottawa, Ontario (Canada)); Akhtar, M.H. (Univ. of Ottawa, Ontario (Canada))

    1990-04-01

    Wheat grains treated with radiolabeled deltamethrin ((S)-{alpha}-cyano-3-phenoxybenzyl (1R,3R)-cis-3-(2,2-dibromovinyl)-2,2-dimethylcyclopropanecarboxylate) and stored in the laboratory for 168 days formed bound (nonextractable) {sup 14}C residues. The amount of bound {sup 14}C residues formed was about 11% of the total {sup 14}C in stored grain. Br{sub 2}CA (3-(2,2-dibromovinyl)-2,2-dimethylcyclopropanecarboxylic acid) and 3-PBacid (3-phenoxybenzoic acid) were present in the form of bound {sup 14}C residues in addition to some radiolabeled product of unknown composition. The stored wheat containing bound {sup 14}C was fed to rats. The {sup 14}C residues were excreted in urine and feces in nearly equal proportion. The {sup 14}C residues identified in urine were Br{sub 2}CA, 3-PBacid, and conjugated compounds of 4{prime}-OH-3-PBacid (3-(4-hydroxyphenoxy)benzoic acid). Most of the {sup 14}C residues excreted in feces were extractable with methanol. Trace amounts of {sup 14}C residues were also present in lungs, kidney, and liver. The results suggest that bound residues in stored wheat treated with deltamethrin when fed to rats are highly bioavailable.

  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. 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

  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. 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)

  6. Helicobacter pylori infection studies using 14C UBT method

    International Nuclear Information System (INIS)

    Swaroop, K.; Somashekarappa, H.M.; Patil, Shrikanth L.

    2012-01-01

    Carbon 14 ( 14 C) is a naturally occurring radioactive isotope of carbon. The half-life of 14 C is about 5,730 years, and it decays by emitting a low energy beta (â) particle of mean energy 49 KeV. The biological half life of 14 C is 10 to 12 days. 14 C is present in the environment and in all organic materials and behaves in the environment in the same manner as other carbon isotopes. In medicine, 14 C can be injected to study abnormalities of metabolism that underlie diabetes, gout, anaemia and acromegaly (adult 'gigantism'), and for diagnosis of Helicobacterpylori (H pylori), The discovery H Pylori by Warren and Marshall in 1982 changed the approach to treat peptic ulcer disease (PUD), Since then H pylori has been the focus of clinical research and debate. The causal relationship between H pylori infection and chronic gastritis is well established, H pylori infection is one of the most common human infections worldwide. This organism has been shown to infect over half of the world's population. By the application of radiation much progress has been made worldwide in the field of medicine. This article presents the application of 14 C Urea Breath Test ( 14 C UBT) for the diagnosis of the H pylori bacteria which present in the stomach and duodenum, 14 C UBT relies on the urease activity of H pylori to detect the presence of active infection. Board of Radiation and Isotope Technology (BRIT), Mumbai has developed 14 C UBT method and already in regular practice in many hospitals across the country. Orally administered 14 C urea will be hydrolyzed into ammonia (NH 4 ) and 14 C labelled carbon dioxide ( 14 CO 2 ). The presence of a significant amount of ( 14 CO 2 ) in the exhaled breath indicates active H pylori infection. 14 C UBT is relatively inexpensive, is easy to perform, and does not require endoscopy. 14 C UBT has proved to be one of the most accurate methods for assessing H pylori status. The ionizing radiation dose involved in this test is extremely low

  7. 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 14 C 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)

  8. 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

  9. 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

  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. Carbon and 14C distribution in tropical and subtropical agricultural soils

    Science.gov (United States)

    Prastowo, Erwin; Grootes, Pieter; Nadeau, Marie

    2016-04-01

    Paddy soil management affects, through the alternating anoxic and oxic conditions it creates, the transport and stabilisation of soil organic matter (SOM). Irrigation water may percolate more organic materials - dissolved (DOM) and colloidal - into the subsoil during anoxic conditions. Yet a developed ploughpan tends to prevent C from going deeper in the subsoil and partly decouple C distribution in top and sub soil. We investigate the influence of different soil type and environment. We observed the C and 14C distribution in paddy and non-paddy soil profiles in three different soil types from four different climatic regions of tropical Indonesia, and subtropical China. Locations were Sukabumi (Andosol, ca. 850 m a.s.l), Bogor (clayey Alisol, ca. 240 m a.s.l), and Ngawi (Vertisol, ca. 70 m a.s.l) in Jawa, Indonesia, and Cixi (Alisol(sandy), ca. 4 - 6 m a.s.l) in Zhejiang Province, China. We compared rice paddies with selected neighbouring non-paddy fields and employed AMS 14C as a tool to study C dynamics from bulk, alkali soluble-humic, and insoluble humin samples, and macrofossils (plant remains, charcoal). Our data suggest that vegetation type determines the quantity and quality of biomass introduced as litter and root material in top and subsoil, and thus contributes to the soil C content and profile, which fits the 14C signal distribution, as well as 13C in Ngawi with C4 sugar cane as upland crop. 14C concentrations for the mobile humic acid fraction were generally higher than for bulk samples from the same depth, except when recent plant and root debris led to high 14C levels in near-surface samples. The difference in sampling, - averaged layer for bulk sample and 1-cm layer thickness for point sample - shows gradients in C and 14C across the layers, which could be a reason for discrepancies between the two. High 14C concentrations - in Andosol Sukabumi up to 111 pMC - exceed the atmospheric 14CO2concentration in the sampling year in 2012 (˜ 103 pMC) and

  12. 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.

  13. 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

  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. 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)

  16. Multi-method identification of 14C-labelled chlorsulfuron

    International Nuclear Information System (INIS)

    Ye Qingfu; Sun Jinhe; Wu Jianmin

    2002-01-01

    The chemical purity of 14 C-labelled chlorsulfuron was determined by HPLC, its radiochemical purity was measured by HPLC-LSC (Liquid scintillation counter) and TLC-Isotope imaging analysis, respectively. The results showed that the chemical and radiochemical purity of synthetic 14 C-chlorsulfuron are 94.4% and 94.7-95.2%, respectively. Results determined by LC-MS showed that the retention time of synthetic 14 C-chlorsulfuron was consistent with that of its standard sample, and the molecular weight determined by MS was 357 that is equal to the molecular weight of chlorsulfuron

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

    Energy Technology Data Exchange (ETDEWEB)

    Stan-Sion, C., E-mail: stansion@nipne.ro [Horia Hulubei National Institute of Physics and Nuclear Engineering (IFIN-HH), Bucharest (Romania); Enachescu, M.; Ghita, D.G.; Calinescu, C.I.; Petre, A.; Mosu, D.V. [Horia Hulubei National Institute of Physics and Nuclear Engineering (IFIN-HH), Bucharest (Romania); Klein, M. [High Voltage Engineering Europa B.V., Amsterdamsweg 63, 3812 RR Amersfoort P.O. Box 99, 3800 AB Amersfoort (Netherlands)

    2014-01-15

    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 {sup 14}C, {sup 10}Be, and {sup 26}Al, and {sup 129}I. The results of an acceptance test are presented and demonstrate that this machine is capable of routine {sup 14}C age dating and of measurements of other radioisotopes in terms of accuracy and precision as well as a low background level.

  18. Difference of 14C turnovers in brain and in transplanted glioma after intravenous injection of 14C-1-pyruvate rats

    International Nuclear Information System (INIS)

    Hara, Toshihiko; Yokoi, Fuji

    1986-01-01

    Carbon 14 from 14 C-1-pyruvate injected intravenously into glioma-transplanted rats was incorporated into various compounds in the brain and in the tumor. In the brain the majority of activity was found in CO 2 (60%), and minor activities were found in alanine, lactate (15%), glutamate, and aspartate, with decreasing order, 5 min after injection. In the tumor, at 5 min. the largest activity was in lactate (56%), and lower activities were found in CO 2 (24%), alanine, glutamate, and aspartate. The total 14 C concentration in the tumor was twice that in the brain at 5 min and 15 min. The results was in accordance with the prediction that in brain, where the mitochondrial function is active, 14 C-1-pyruvate will be oxidized completely into 14 CO 2 , and that in tumor, where the mitochondrial function is insufficient, 14 C-1-pyruvate will be converted only into 14 C-lactate and prevent further degradation. It may be assumed that this difference in the turnover of 14 C and 14 C-1-pyruvate between brain and tumor could constitute a basis for the ''hot'' visualization of human brain tumor using cyclotron-produced 11 C-1-pyruvate and positron-emission tomography. (orig.)

  19. Synthesis of (/sup 14/C)-labelled dihydropyridine calcium channel entry blockers: nicardipine-(4(/sup 14/C) and RS-93522-(4-/sup 14/C). [Antihypertensive agents

    Energy Technology Data Exchange (ETDEWEB)

    Parnes, H.; Huang, G.T.; Shelton, E.J.

    1988-06-01

    The Hantzsch synthesis has been applied to the general preparation of 4-aryl-dihydropyridines labelled in the metabolically stable 4-position of the dihydropyridine ring. The synthesis is based on the preparation of a key common intermediate, m-nitrobenzaldehyde-(formyl-/sup 14/C), in high yield from Ba/sup 14/CO/sub 3/.

  20. 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

  1. Determination of 14C content in fermentation alcohols

    International Nuclear Information System (INIS)

    Martiniere, Pierre; Severac, Jean

    1976-01-01

    The measuring of activity in 14 C of ethylic alcohol permits to distinguish fermentation alcohol from synthetic alcohol. This activity is used to determine the corresponding percentages of these alcohols in cases of mixture [fr

  2. 14C-age tracers in global ocean circulation models

    Science.gov (United States)

    Koeve, W.; Wagner, H.; Kähler, P.; Oschlies, A.

    2014-10-01

    The natural abundance of 14C in total CO2 dissolved in seawater is a property applied to evaluate the water age structure and circulation in the ocean and in ocean models. In this study we use three different representations of the global ocean circulation augmented with a suite of idealised tracers to study the potential and limitations of using natural 14C to determine water age, the time elapsed since a body of water had contact with the atmosphere. We find that, globally, bulk 14C-age is dominated by two equally important components, one associated with aging, i.e. the time component of circulation and one associated with a "preformed 14C-age". This latter quantity exists because of the slow and incomplete atmosphere/ocean equilibration of 14C in particular in high latitudes where many water masses form. The relative contribution of the preformed component to bulk 14C-age varies regionally within a given model, but also between models. Regional variability, e.g. in the Atlantic Ocean is associated with the mixing of waters with very different end members of preformed 14C-age. In the Atlantic, variations in the preformed component over space and time mask the circulation component to an extent that its patterns are not detectable from bulk 14C-age alone. Between models the variability of age can also be considerable (factor of 2), related to the combinations of physical model parameters, which influence circulation dynamics, and gas exchange in the models. The preformed component was found to be very sensitive to gas exchange and moderately sensitive to ice cover. In our model evaluation exercise, the choice of the gas exchange constant from within the current range of uncertainty had such a strong influence on preformed and bulk 14C-age that if model evaluation would be based on bulk 14C-age it could easily impair the evaluation and tuning of a models circulation on global and regional scales. Based on the results of this study, we propose that considering

  3. 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

  4. 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

  5. Synthesis of [1-14C] palmitic acid

    International Nuclear Information System (INIS)

    Tian Yuan; Han Peizhen; Tian Shuhao

    1997-01-01

    The synthesis of [1- 14 C] palmitic acid via Grignard Reaction is reported. The carbon-C 14 dioxide was liberated by dropping sulfuric acid onto barium carbonate-C 14 . The yield of [1- 14 C] palmitic acid was 44.8%. A radiochemical purity of more than 99.5% was determined by HPLC and the product was proved to be free of impurity by TLC

  6. Elements in biological AMS

    Energy Technology Data Exchange (ETDEWEB)

    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. {sup 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.

  7. 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

  8. 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

  9. 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.

  10. 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.

  11. 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

  12. 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)

  13. Comparison of different soil organic matter fractionation methodologies: Evidences from ultrasensitive {sup 14}C measurements

    Energy Technology Data Exchange (ETDEWEB)

    Marzaioli, Fabio, E-mail: fabio.marzaioli@unina2.i [CIRCE, Dipartimento di Scienze Ambientali, Seconda Universita degli studi di Napoli and INNOVA, Via Vivaldi, 43, Caserta 81100 (Italy); Lubritto, Carmine; Galdo, Ilaria Del; D' Onofrio, Antonio [CIRCE, Dipartimento di Scienze Ambientali, Seconda Universita degli studi di Napoli and INNOVA, Via Vivaldi, 43, Caserta 81100 (Italy); Cotrufo, M. Francesca [CIRCE, Dipartimento di Scienze Ambientali, Seconda Universita degli studi di Napoli and INNOVA, Via Vivaldi, 43, Caserta 81100 (Italy); Department of Soil and Crop Sciences, Colorado State University, Fort Collins, Colorado (United States); Terrasi, Filippo [CIRCE, Dipartimento di Scienze Ambientali, Seconda Universita degli studi di Napoli and INNOVA, Via Vivaldi, 43, Caserta 81100 (Italy)

    2010-04-15

    Soils are studied with the aim to predict future climatic scenarios and find the best guidelines to manage terrestrial ecosystems for the mitigation of the atmospheric CO{sub 2} rising. Carbon constituting soil organic matter (SOM) behaves as a cohort of different pools, characterized by a specific C turnover time. Both natural and anthropogenic occurring {sup 14}C reach the soil through plant littering, becoming a valid tool to trace SOM dynamics. In this study we present a series of Accelerator Mass Spectrometry (AMS) {sup 14}C measurements on SOM samples obtained by means of different laboratory protocols used for the isolation of soil pools from bulk soil (fractionation protocols). Radiocarbon signature of SOM fractions is used as a keyhole to look at the more effective fractionation procedure and comparison among measured {sup 14}C on SOM fractions revealed important indications for the proposal of a novel fractionation protocol. Our data put in evidence how particle size controls the recalcitrance of ancient SOM carbon pools.

  14. 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

  15. 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.

  16. 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

  17. The glyceryl [14C] tripalmitate breath test: A reassessment

    International Nuclear Information System (INIS)

    Strange, R.C.; Reid, J.; Holton, D.; Percy-Robb, I.W.; Jewell, N.P.

    1980-01-01

    Several reports have been published commending the use of 14 C-labelled triglyceride breath tests in the assessment of fat malabsorption. The authors report further studies using glyceryl [ 14 C]tripalmitate. Corrections for age, weight or metabolic rate failed to improve the test's ability to discriminate between malabsorbers and control subjects. A correction for respiratory quotient improved the linear correlation observed between the breath test results and daily faecal fat excretion. The significance of these findings is discussed and a number of problems identified which, at present, are preventing the introduction of breath tests for fat malabsorption into routine clinical practice. (Auth.)

  18. Biliary excretion of intravenous (/sup 14/C) omeprazole in humans

    Energy Technology Data Exchange (ETDEWEB)

    Lind, T.; Andersson, T.; Skanberg, I.O.; Olbe, L.

    1987-11-01

    We have studied the biliary excretion of (/sup 14/C) omeprazole in humans. The study was performed in eight healthy subjects and the technique used was based on multiple marker dilution principles with double-lumen tubes placed in both the stomach and intestine. The results obtained show a 16% biliary excretion of (/sup 14/C) omeprazole. These data suggest a minimal spillover of omeprazole from the gastric mucosa into the gastric lumen in humans. The results also agree with previous data of the fecal recovery of radiolabeled omeprazole that suggest that the fecal excretion of intravenous omeprazole in humans is entirely accounted for by biliary excretion.

  19. Biliary excretion of intravenous [14C] omeprazole in humans

    International Nuclear Information System (INIS)

    Lind, T.; Andersson, T.; Skanberg, I.O.; Olbe, L.

    1987-01-01

    We have studied the biliary excretion of [ 14 C] omeprazole in humans. The study was performed in eight healthy subjects and the technique used was based on multiple marker dilution principles with double-lumen tubes placed in both the stomach and intestine. The results obtained show a 16% biliary excretion of [ 14 C] omeprazole. These data suggest a minimal spillover of omeprazole from the gastric mucosa into the gastric lumen in humans. The results also agree with previous data of the fecal recovery of radiolabeled omeprazole that suggest that the fecal excretion of intravenous omeprazole in humans is entirely accounted for by biliary excretion

  20. 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

  1. 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

  2. Synthesis of [sup 14]C-radiolabeled ractopamine hydrochloride

    Energy Technology Data Exchange (ETDEWEB)

    Terando, N.H. (DowElanco, Greenfield Labs., Greenfield, IN (United States))

    1992-09-01

    Ractopamine HC1 was uniformly labeled with carbon-14 in one of two phenyl rings as a requirement for animal metabolism studies. The six-step synthesis was completed in a 14% yield. Product instability on silica gel complicated purification, but development of a chromatographic method afforded ractopamine HCl-[sup 14]C with a radiochemical purity of 98.2%. (author).

  3. 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

  4. Production of a negative 14C beam from tantalum carbides

    International Nuclear Information System (INIS)

    Dumail, M.

    1978-01-01

    In order to obtain several tens nano Amps negative 14 C beam for the Orsay MP Tandem in good conditions of yield and safety, a method for fabrication of polycristalline Ta carbides (Ta 2 C, TaC) has been developped, allowing only one handling [fr

  5. 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%.

  6. 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)

  7. 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

  8. 14C measurements in Bulgarian and Hungarian wines from 1986

    International Nuclear Information System (INIS)

    Yanev, Y.; Kostadinov, K.N.; Chapkanova, G.; Fodor-Csanyi, P.

    1989-01-01

    The measurements of 14 C in ethanol samples extracted from wines of different wine districts in Bulgaria and Hungary in 1986 showed that the atmospheric reservoir remained practically undisturbed by the emission due to the Chernobyl accident. (author) 11 refs.; 1 fig.; 1 tab

  9. Bound residues of 14C-chlorotoluron in soil

    International Nuclear Information System (INIS)

    Chen Zuyi; Shi Ying; Huang Shile

    1992-07-01

    Dynamics of bound residues of 14 C-chlorotoluron, distribution of the bound residues in the components of humus, and their absorption by step-crop (rice) were investigated in paddy soil and black soil under simulated aerobic and anaerobic conditions respectively. The results show that: (1) The bound residues of 14 C-chlorotoluron in soil were very considerable and increasing with the incubation time. The organic substance and humidity contained in the soil affected the bound residues remarkably. The bound residues in black soil with more organic substance and clay particles were higher than those in paddy soil, and under anaerobic conditions were higher than under aerobic conditions. (2) Bound residues of 14 C-chlorotoluron mainly bound with the components of soil humus, the distribution of which was in the order of humin>humic acid>fulvic acid. (3) Bound residues of 14 C-chlorotoluron in soils could be absorbed by step-crop (rice) and moved to the upper part, that would cause chemical injury, chlorosis and necrosis for the leaf tip

  10. 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

  11. 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

  12. 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

  13. 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

  14. 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

  15. 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.  

  16. 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.

  17. 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.)

  18. 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)

  19. 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)

  20. 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.

  1. The fate of [2-14C] carbendazol in rats

    International Nuclear Information System (INIS)

    Pan Shangren; Shao Hesheng; Jing Xinan

    1989-01-01

    The [2- 14 C] carbendazol was administered to rats 60 mg/kg PO. The biological half-life T 1/2α was 1.1 h and T 1/2β was 4.6 h. Radioactivities reached to the highest in liver after 48 h. The percentage of dose excreted was 63% in urine and 30% in feces within 48 h. The metabolites were checked by TLC and radioautography of the urine

  2. 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)

  3. 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%).

  4. Studies on bound (14)C-chlorsulfuron residues in soil.

    Science.gov (United States)

    Guo, Jiangfeng; Sun, Jinhe

    2002-04-10

    The cause for phytotoxicity of bound residues of chlorsulfuron (2-chloro-N-[[4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino] carbonyl]benzenesulfonamide) to rotational crops is unknown. This study was conducted to determine the formation of nonextractable (bound) residues of chlorsulfuron in soil, and the distribution of bound residues in different organic matter fractions. The results showed that over 150 days, the extractable fraction of (14)C-residues decreased to 25.1% of applied chlorsulfuron, while bound residues concurrently increased to 47.1%. The distribution of (14)C-bound residues in soil organic matter fractions followed an order of humic acid (HA) humin humin fraction increased with time. After soil treatment by autoclaving, it was found that bound (14)C-chlorsulfuron residues became available again in the soil. One of the released products was 2-amino-4-hydroxyl-6-methyl-1,3,5-triazine (identified by GC-MS), which is a degradation product of chlorsulfuron.

  5. 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)

  6. 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)

  7. Migration of {sup 14}C in the paddy soil-to-rice plant system after {sup 14}C-acetic acid breakdown by microorganisms below the plow layer

    Energy Technology Data Exchange (ETDEWEB)

    Ogiyama, Shinichi, E-mail: ogiyama@nirs.go.j [Office of Biospheric Assessment for Waste Disposal, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Takeda, Hiroshi; Ishii, Nobuyoshi; Uchida, Shigeo [Office of Biospheric Assessment for Waste Disposal, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan)

    2010-02-15

    Migration of {sup 14}C derived from {sup 14}C-acetic acid was examined by using soils sampled from paddies in four administrative areas in Japan (Aomori, Yamanashi, Ehime and Okinawa) and rice plant in a tracer experiment to understand the fate of {sup 14}C in the paddy soil-to-rice plant system. The loss of {sup 14}C radioactivity levels derived from {sup 14}C-acetic acid was caused by soil microorganism breakdown. A part of the {sup 14}C fixation to soil was caused by microbial assimilation into the fatty acid fraction. {sup 14}C moved upward via two different types of {sup 14}C dynamics in soil: quick movement upward; and constant but slow movement upward. {sup 14}C was highly assimilated into the plant panicle and that was caused by the root-uptake and the transfer of {sup 14}C. Migration of {sup 14}C derived from {sup 14}C-acetic acid relied heavily upon changes of chemical forms and characteristics of {sup 14}C-compound as caused by microorganisms in soil.

  8. Radiocarbon dating of charred human bone remains preserved in urns excavated from medieval Buddhist cemetery in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Toshio, E-mail: nakamura@nendai.nagoya-u.ac.j [Center for Chronological Research, Nagoya University, Chikusa, Nagoya 464-8602 (Japan); Sagawa, Shinichi; Yamada, Tetsuya [Gangoji Institute for Research of Cultural Properties, Nakain, Nara 630-8392 (Japan); Kanehara, Masaaki [School of Science Education, Nara University of Education, Takabatake, Nara 630-8528 (Japan); Tsuchimoto, Norio [Ichinomiya City Museum, Yamato, Ichinomiya 491-0922 (Japan); Minami, Masayo [Center for Chronological Research, Nagoya University, Chikusa, Nagoya 464-8602 (Japan); Omori, Takayuki [Graduate School of Environmental Studies, Nagoya University, Chikusa, Nagoya 464-8602 (Japan); Okuno, Mitsuru [Faculty of Science, Fukuoka University, Jonan, Fukuoka 814-0180 (Japan); Ohta, Tomoko [Center for Chronological Research, Nagoya University, Chikusa, Nagoya 464-8602 (Japan)

    2010-04-15

    For a preliminary test of {sup 14}C dating of cremated human remains, we have collected charred bone and wood-charcoal fragments from cremated remains contained in cinerary urns that had been excavated from medieval Buddhist cemetery at the Hoenji temple in Aichi prefecture, central Japan. More than 230 urn vessels were discovered from the excavated area of ca. 14 m wide and 14 m long. The identification of charred bone or charcoal fragments among the remains was performed by observation of surface appearance, inspection of fine structures by a microscope, bubble formation during the HCl treatments in preparing target material for AMS {sup 14}C dating, carbon and nitrogen contents, delta{sup 13}C and delta{sup 15}N values of the fragments. All {sup 14}C ages obtained for the samples that were identified as charred bone remains were almost consistent with the archeological age estimated based on typological analysis of respective urns. On the other hand, some {sup 14}C ages for the remains identified as wood charcoal, which had been produced from firewood or a wooden coffin during the cremation, were not consistent with archeological estimation, shifting toward older {sup 14}C ages, most probably as the result of old wood effect.

  9. 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

  10. 7Li(15N,14C8Be reaction and 13,14C + 8Be nuclei interactions

    Directory of Open Access Journals (Sweden)

    А. Т. Rudchik

    2017-12-01

    Full Text Available Angular distributions of the 7Li(15N,14C8Be reaction were measured at the energy Elab(15N = 81 MeV. The reaction data were analyzed within coupled-reaction-channels (CRC method. The 7Li + 15N elastic and inelastic scattering and the more important one- and two-step transfers of this reaction were included in the channels-coupling scheme. Previously the 7Li + 15N optical potential parameters were deduced from the CRC analysis of the 7Li + 15N elastic scattering data at Elab(15N = 81 MeV. The spectroscopic amplitudes needed for CRC-calculations of the reaction were calculated within the translational invariant shell model (TISM. CRC analysis of the 7Li(15N,14C reaction data showed the p transfer dominants in this reaction. The parameters of the 14C + 8Be optical potential were deduced from CRC analysis of the reaction data and were compared with that of the 13C + 8Be potential parameters deduced previously from CRC analysis of 9Be(12C,13C8Be reaction data. The isotopic differences are observed.

  11. Mineralization of ( sup 14 C)hexadecane and ( sup 14 C)phenanthrene in crude oil: Specificity among bacterial isolates

    Energy Technology Data Exchange (ETDEWEB)

    Foght, J.M.; Fedorak, P.M.; Westlake, D.W.S. (Univ. of Alberta, Edmonton, AB (Canada))

    1990-01-01

    Bacteria isolated from freshwater, marine, and estuarine samples were tested for the ability to produce {sup 14}CO{sub 2} from n-(1-{sup 14}C)hexadecane or (9-{sup 14}C)phenanthrene added to Prudhoe Bay crude oil. Of 138 isolates tested, 54 (39%) mineralized the model aliphatic compound hexadecane and 6 (4%) mineralized the model aromatic compound phenanthrene. None mineralized both compounds. There was no apparent correlation between degradative ability and genus or source. Additional hydrocarbon-degrading bacteria from diverse sources were tested and found to mineralize either hexadecane or phenanthrene. Of 61 hexadecane- and 21 phenanthrene-mineralizing bacteria tested, none mineralized both model compounds. Selected isolates and commercially available cultures were tested for mineralization of specific {sup 14}C-labelled mono-, di-, and tri-cyclic aromatics. An apparent hierarchy of degradation was observed: strains mineralizing the mono- and di-cyclic aromatics toluene and napthalene did not mineralize biphenyl or the tricyclic aromatics anthracene and phenanthrene, whereas those strains that mineralized the tricyclic aromatics also mineralized the smaller substrates. Similarly, not all n-alkane-mineralizing isolates tested mineralized the isoprenoid pristane. A combined culture consisting of one aliphatic- and one aromatic-degrading isolate was tested for mineralization of the model compounds and for degradation of other crude oil components by gas chromatography. No synergism or antagonism was observed compared with degradation by the individual isolates. 31 refs., 2 figs., 3 tabs.

  12. Synthesis of metabolites of the insecticide Deltamethrine: 3-phenoxy (carboxyl-14C) benzoic acids and 3-phenoxy (hydroxymethyl-14C) benzyl alcohols

    International Nuclear Information System (INIS)

    Do-Cao-Thang; Nguyen-Hoang-Nam; Hoellinger, H.; Pichat, L.; CEA Centre d'Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette

    1985-01-01

    Procedures are described for the synthesis of the following metabolites of Deltamethrin, the pyrethroid insecticide: 3-phenoxy (carboxyl- 14 C) benzoic acid, 3-(4'-hydroxyphenoxy) (carboxyl- 14 C) benzoic acid, 3-(2'-hydroxyphenoxy) (carboxyl- 14 C) benzoic acid and the corresponding 3-phenoxybenzyl alcohols, specific activity = 47-57 mCi/mmol. (author)

  13. Extension of the HVE 1 MV multi-element AMS system for low background

    Energy Technology Data Exchange (ETDEWEB)

    Klein, M., E-mail: info@highvolteng.com [High Voltage Engineering Europa B.V., Amersfoort (Netherlands); Heinemeier, J. [AMS " 1" 4C Dating Centre, Department of Physics and Astronomy, Aarhus University, Aarhus (Denmark); Gottdang, A.; Mous, D.J.W. [High Voltage Engineering Europa B.V., Amersfoort (Netherlands); Olsen, J. [AMS " 1" 4C Dating Centre, Department of Physics and Astronomy, Aarhus University, Aarhus (Denmark)

    2014-07-15

    HVE has extended its 1 MV multi-element AMS system to enhance its performance on elements like {sup 10}Be and {sup 14}C as well as actinides like Pu. The original system is very compact, but had some inherent limitations on e.g. background and the mass resolution of the injector magnet. With the extension, system performance has improved in several aspects: For actinide measurements, the low-energy spectrometer is equipped with a 120 ° magnet featuring a high mass resolution (M/ΔM > 1000) and a high bending power (340 amu at 35 keV), supporting e.g. injection of {sup 244}Pu{sup 19}F{sub 5}. For {sup 3}H AMS, all magnets are equipped with Hall-probe control. The accelerator is equipped with a dual gas stripper system. The high energy spectrometer was extended by a 30 degree magnet removing ions scattering in the high-energy ESA. This has improved the background for {sup 10}Be AMS by two orders of magnitude down to the low 10{sup −16}. For {sup 14}C AMS the magnet allows using charge state 1+ by suppressing scattered {sup 13}C to a level also in the low 10{sup −16}. The new system has a footprint of 10.4 m × 4.9 m, including a second ion source in the injector and provisions for future implementation of an isobar separator for anions (ISA) for e.g. {sup 36}Cl measurements. The first extended system will be delivered to the Aarhus AMS {sup 14}C Dating Centre.

  14. 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.

  15. Sedimentary environment, lithostratigraphy and dating of sediment sequences from Arctic lakes Revvatnet and Svartvatnet in Hornsund, Svalbard

    Directory of Open Access Journals (Sweden)

    Ojala Antti E.K.

    2016-03-01

    Full Text Available The sedimentary environment, sediment characteristics and age-depth models of sediment sequences from Arctic lakes Revvatnet and Svartvatnet, located near the Polish Polar Station in Hornsund, southern Svalbard (77°N, were studied with a view to establishing a basis for paleolimnological climate and environmental reconstructions. The results indicate that catchment-to-lake hydroclimatic processes probably affect the transportation, distribution and accumulation of sediments in different parts of lakes Revvatnet and Svartvatnet. Locations with continuous and essentially stable sedimentary environments were found in both lakes between water depths of 9 and 26 m. We used several different dating techniques, including 137Cs, 210Pb, AMS 14C, and paleomagnetic dating, to provide accurate and secured sediment chronologies. Arecovered sequence from the northern basin of Revvatnet spans more than one thousand years long with laminated stratigraphy in the upper part of the sediment. Based on AMS 14C dates, it is possible to suppose that Revvatnet basin was not occupied by a valley glacier during the Little Ice Age. The dates were supported by 137Cs chronologies, but not confirmed with other independent dating methods that extent beyond the last 50 years. A sedimentary sequence from the northern basin of Svartvatnet provides a potential archive for the study of climate and environmental change for the last ca. 5000 years. Based on the stratigraphy and a Bayesian age-depth model of AMS14C and paleosecular variation (PSV dates, the recovered sediment sections represent a continuous and stable sedimentation for the latter half of the Holocene.

  16. 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

  17. 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.

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

    DEFF Research Database (Denmark)

    Heinemeier, Katja Maria; Schjerling, Peter; Heinemeier, Jan

    2013-01-01

    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...... is revealed by nuclear bomb 14C....

  19. 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)

  20. 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)

  1. 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

  2. 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)

  3. 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

  4. 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)

  5. 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

  6. 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

  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. 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

  10. 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

  11. 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

  12. Redistribution of paclobutrazol-14C in soil and plant

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Maria Aparecida; Tornisielo, Valdemar Luiz; Regitano, Jussara Borges [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Lab. de Ecotoxicologia]. E-mail: macosta@cena.usp.br; vltorrnis@cena.usp.br; regitano@cena.usp.br

    2007-07-01

    Paclobutrazol (PBZ) is important to the mango culture since it works as a growth regulator that inhibits gibberellins synthesis controlling the growth of the trees and thus reducing pruning and manipulation during cultivation. Although PBZ has been used for years in mango in Brazil, there are no studies evaluating its environmental fate under Brazilian conditions. Therefore, the objective of the present work is to evaluate the redistribution of PBZ and its metabolites in soil and plant. For this experiment, radiolabeled ({sup 14}C-PBZ) was used once this technique allows detention of minimum amounts of residues in both soil and plant. In addition, plants were cultivated in vessels (100 L and 1 plant /vessel) and the PBZ were applied to the soils at the recommended rate of 1,0 kg ha{sup -1}, having radioactive concentration of 2,0 MBq/vessel. In order to evaluate PBZ redistribution, the volumes of water percolated with rainfall and senescent leaves were collected to monitor their {sup 14}C-residue concentration by liquid scintillation spectrometry (LSS). In parallel, the sorption and leaching potential of PBZ was determined in order to support the previous study. The results showed that PBZ presented relatively low mobility (0.12 % of the applied amount) and high sorption (91.9 % of the applied amount) in the studied soil, being minimal its leached amount; and that majority of the soil applied radioactivity were redistributed in the plant leaves (1.08% of the applied amount). Needing more inquiries in relation to the contamination of the soil and rain water percolated in period of September, 2nd, 2006 to January, 8th, 2007 was of the 0.06% in relation applied radioactivity being very next the radioactivity to deep, indicating that the product still is not being leached during rains. (author)

  13. 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

  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. 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.

  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. Radiocarbon Dating, Memories, and Hopes

    Science.gov (United States)

    Libby, W. F.

    1972-10-01

    The history of radiocarbon dating from 1939 to the present is reviewed. The basic principles of radiocarbon dating are that cosmic rays make living things radioactive with {sup 14}C to a certain level fixed by the environment and that at death the intake of food stops so no replenishment of the {sup 14}C steadily lost by the immutable decay occurs. Therefore measurement of the degree of decay gives the time lapse since death, i.e., the radiocarbon age. The equipment developed and experiments performed to measure the specific activity of specimens to be dated are described. The results obtained by world-wide experimenters are discussed. These showed that on simultaneity radiocarbon dating is apparently reliable but that absolute dates may be incorrect by as much as 600 to 700 y. The value of radiocarbon dating to archaeologists, geologists, climatologists, and historians is stressed. (LCL)

  18. 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.

  19. 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...

  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. 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

  2. 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)

  3. Induction of acropetal (14)C-photosynthate transport and radial growth by indole-3-acetic acid in Pinus sylvestris shoots.

    Science.gov (United States)

    Little, C H; Sundberg, B; Ericsson, A

    1990-06-01

    The relationship between radial growth and assimilate movement was determined in one-year-old Pinus sylvestris (L.) cuttings collected during the dormant period and reactivated for 1-27 days under environmental conditions favorable for growth. The cuttings were either left with buds intact, defoliated along the distal 8 cm, or debudded and treated apically with 0 or 1 mg g(-1) indole-3-acetic acid (IAA) in lanolin. Radial growth was measured as tracheid production and bark radial width. The distribution of (14)C-photosynthate 1 or 5 days after exposure to (14)CO(2) was used to indicate assimilate movement. Debudding inhibited tracheid production and decreased acropetal (14)C-photosynthate transport, whereas applying IAA to debudded cuttings promoted both these processes and, in addition, induced vigorous callus growth within the bark immediately below the application point. Distal defoliation markedly increased the amount of (14)C-photosynthate transported toward the apex without altering how debudding and exogenous IAA affected tracheid production and the distribution of (14)C-photosynthate. The production of tracheids induced by apically applied IAA in debudded and distally defoliated cuttings increased progressively in material collected on September 9, October 14 and November 24, whereas bark radial width and acropetal (14)C-photosynthate movement increased only between the first two collection dates. Ringing midway between the IAA source and the bottom of the distally defoliated region with a lanolin mixture of 10 mg g(-1)N-1-naphthylphthalamic acid (NPA), 1 mg g(-1) methyl-2-chloro-9-hydroxy-fluorene-9-carboxylic acid (CF) or 10 mg g(-1) phenylacetic acid (PAA) reduced radial growth and [1-(14)C]IAA transport below the ring and locally promoted radial growth and accumulated radioactivity above. (14)C-Photosynthate transport into the region above the ring either was not altered (CF, PAA) or was increased (NPA). The results indicate that apically applied IAA

  4. 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.

  5. 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.

  6. Method of preparing 14C-labelled D-aldohexuronic

    International Nuclear Information System (INIS)

    Bilik, V.; Tihlarik, K.; Kratky, Z.; Kolina, J.

    1986-01-01

    N-(4-nitrophenyl)glycosides of D-aldohexoses labelled with 14 C are oxidized with gaseous nitrogen dioxide at temperatures of 20 to 25 degC for a period of 3 to 4 hours. The product is hydrolyzed with diluted organic acid (10% formic acid or acetic acid) at a temperature of 80 to 90 degC for over 4 to 6 hours. Labelled D-aldohexuronic acids are separated from the reaction mixture by paper chromatography in two steps in the system 1-butanol:ethanol:water (5:1:4) and ethyl acetate:acetic acid:water (3:1:1). The relative mobilities are given of uronic acids and saccharides in the systems. The yields are 10 to 15%. Preparation may be simplified by preparing N-phenyl glycosides by aldohexose reaction with, e.g., 4-nitroaniline in a methanol solution (65 degC, 4 hours) and the resulting N-(4-nitrophenyl)glycosides are without any further separation oxidized with nitrogen dioxide and processed using the described procedure. (Ha)

  7. 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

  8. 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

  9. 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

  10. A new AMS facility at the JNC Tono Geoscience Center, Japan

    Science.gov (United States)

    Xu, Sheng; Ito, Shigeru; Iwatsuki, Teruki; Abe, Masahito; Watanabe, Masato

    2000-10-01

    A new AMS facility (NEC 15SDH-2) based on a 5 MV tandem accelerator has been installed at the Japan Nuclear Cycle Development Institute (JNC) Tono Geoscience Center in March 1997. It has two cesium sputter negative ion sources (for solid and gas samples) which are connected to a fast sequential injection beam line. A number of performance tests have been done on the MC-SNICS solid source for radiocarbon. Precision measurements with modern samples have shown that a precision below 0.5% is feasible on a routine basis. The 14C background of the machine and the chemistry blank are 0.04 and 0.10 pMC respectively, indicating a 14C dating limit of 56,000 yr BP. The normalized JNC 14C values for IAEA standard materials (C-2 to C-8) agree well with the nominal values. Since October 1998, the MC-SNICS solid source is used for routine radiocarbon dating. Preliminary results of performance tests of the MGF-SNICS gas source are reported, too.

  11. A new AMS facility at the JNC Tono Geoscience Center, Japan

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Sheng E-mail: xu@tono.jnc.go.jp; Ito, Shigeru; Iwatsuki, Teruki; Abe, Masahito; Watanabe, Masato

    2000-10-01

    A new AMS facility (NEC 15SDH-2) based on a 5 MV tandem accelerator has been installed at the Japan Nuclear Cycle Development Institute (JNC) Tono Geoscience Center in March 1997. It has two cesium sputter negative ion sources (for solid and gas samples) which are connected to a fast sequential injection beam line. A number of performance tests have been done on the MC-SNICS solid source for radiocarbon. Precision measurements with modern samples have shown that a precision below 0.5% is feasible on a routine basis. The {sup 14}C background of the machine and the chemistry blank are 0.04 and 0.10 pMC respectively, indicating a {sup 14}C dating limit of 56,000 yr BP. The normalized JNC {sup 14}C values for IAEA standard materials (C-2 to C-8) agree well with the nominal values. Since October 1998, the MC-SNICS solid source is used for routine radiocarbon dating. Preliminary results of performance tests of the MGF-SNICS gas source are reported, too.

  12. 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

  13. 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

  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. 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...

  16. Distribution of aged 14C-PCB and 14C-PAH residues in particle-size and humic fractions of an agricultural soil.

    Science.gov (United States)

    Doick, Kieron J; Burauel, Peter; Jones, Kevin C; Semple, Kirk T

    2005-09-01

    Organic matter is considered to be the single most importantfactor limiting availability and mobility of persistent organic pollutants (POPs) in soil. This study aimed to characterize the distribution of 14C-PCB (congeners 28 and 52) and 14C-PAH (fluoranthene and benzo[a]pyrene) residues in an Orthic Luvisol soil obtained from two lysimeter studies initiated in 1990 at the Agrosphere Institute (Forschungszentrum Jülich GmbH, Germany). The lysimeter soils contained a low-density OM fraction, isolated during soil washing, which contained a significant fraction (3-12%) of the total 14C-activity. Soils were also fractionated according to three particle sizes: >20, 20-2, and (20 microm) for the PCBs. Relative affinity values of 14C-activity for the different particle sizes varied in the order 20-2 microm > ( (>20 microm) for the PAHs. The distribution of 14C-PCB or 14C-PAH residues in the organic and inorganic matrixes of the particle-size fractions was determined using methyl isobutyl ketone (MIBK). 14C-PCB and 14C-PAH-associated activities were primarily located in the humin fraction of the 20-2 and soil. A small fraction was associated with the fulvic and humic acid fractions; these were quantitatively more important for the PAHs than the PCBs. There appeared to be a high degree of association of 14C-activity with the mineral fraction following MIBK separation of the humic fractions, ranging between 8 and 52% for 14C-PCBs and 57-80% for 14C-PAHs. The mineral (inorganic) component of the soils apparently played a significant (previously unreported) role in the sequestration of both PCBs 28 and 52 and the PAHs fluoranthene and benzo[a]pyrene.

  17. Radiocarbon dating at sub MeV energies

    International Nuclear Information System (INIS)

    Synal, H.A.; Jacob, S.; Suter, M.

    1999-01-01

    Accelerator Mass Spectrometry (AMS) is currently the leading technique for the detection of long-lived radionuclides, such as 10 Be, 14 C, 26 Al, 36 Cl, 41 Ca, 53 Mn, 59 Ni, 60 Fe and 129 I at natural isotopic concentrations. However, radiocarbon plays the primary role and 14 C AMS systems, which are able to provide high precision measurements, are nowadays commercially available

  18. Radiocarbon dating of silica sinter deposits in shallow drill cores from the Upper Geyser Basin, Yellowstone National Park

    Science.gov (United States)

    Lowenstern, Jacob B.; Hurwitz, Shaul; McGeehin, John P.

    2016-01-01

    To explore the timing of hydrothermal activity at the Upper Geyser Basin (UGB) in Yellowstone National Park, we obtained seven new accelerator mass spectrometry (AMS) radiocarbon 14C ages of carbonaceous material trapped within siliceous sinter. Five samples came from depths of 15-152 cm within the Y-1 well, and two samples were from well Y-7 (depths of 24 cm and 122 cm). These two wells, at Black Sand and Biscuit Basins, respectively, were drilled in 1967 as part of a scientific drilling program by the U.S. Geological Survey (White et al., 1975). Even with samples as small as 15 g, we obtained sufficient carbonaceous material (a mixture of thermophilic mats, pollen, and charcoal) for the 14C analyses. Apparent time of deposition ranged from 3775 ± 25 and 2910 ± 30 14C years BP at the top of the cores to about 8000 years BP at the bottom. The dates are consistent with variable rates of sinter formation at individual sites within the UGB over the Holocene. On a basin-wide scale, though, these and other existing 14C dates hint that hydrothermal activity at the UGB may have been continuous throughout the Holocene.

  19. Imprint of CO2 emission in atmosphere and biosphere on the basis of 14C and 13C measurements

    Science.gov (United States)

    Pazdur, Anna; Gabryś, Alicja; Kuc, Tadeusz; Pawełczyk, Sławomira; Piotrowska, Natalia; Rakowski, Andrzej; Różański, Kazimierz; Sensuła, Barbara

    2015-04-01

    As is shown in the IPCC (Intergovernmental Panel on Climate Change) report, the observed climate changes are caused, among others, by human activity. Mainly emission of CO2 to the atmosphere coming from the burning of fossil fuels, can have dire consequences for life on Earth and development of humankind. The report uses, among others, data obtained from isotopic measurements in the biosphere. Measurements of 14C and 13C concentration in modern atmospheric carbon dioxide and biosphere allow the determination of the decrease of the concentration of this isotope. Furthermore, the magnitude of emission to the atmosphere of carbon dioxide not containing the isotope 14C can be estimated on this basis. Such emission stems from fossil fuel combustion - petroleum, natural gas and black coal. A sensitive bioindicator of the emission are annual tree rings. The measurements of 14C concentration in tree ring material using AMS allow to see its seasonal changes. Trees, treated as an archive of changes in conjunction with information about the isotopic composition of carbon can be used for monitoring of environment as sensitive bioindicators on local, as well as on the global scale. Regular investigations of isotopic composition of carbon in trees have been carried out in the GADAM Centre for the urban areas of both Poland and worldwide. This method can be applied in the study of the emission of CO2 to the atmosphere and its spatial and temporal distribution connected with the production of energy by power plants based on fossil fuel combustion for the area of southern Poland. Modelling of CO2 emission using both 14C and 13C carbon isotopes measured in pine tree rings on the background of climatic changes will be presented. The national ecological policy in the era of global warming requires the manufacturers of energy to get involved in the development of methods suitable for monitoring the state of the environment. Hence, the interest in the area of monitoring the fossil fuel

  20. Synthesis of two 14C-labeled catechol-o-methyltransferase inhibitors

    International Nuclear Information System (INIS)

    Karlsson, Carita; Honkanen, Erkki

    1991-01-01

    14 C-labelled 3-(3,4-dihydroxy-5-nitrophenylmethylidene)-2,4-pentanedione and 14 C-labelled E-N,N-diethyl-2-cyano-3-(3,4-dihydroxy-5-nitrophenyl)acrylamide have been synthesized from [carbonyl- 14 C]vanillin. (author)

  1. An enzymic method for the determination of [1-14C] lactose

    International Nuclear Information System (INIS)

    Davies, E.; Bourke, E.; Costello, J.

    1975-01-01

    A simple, rapid and specific method for the determination of [1- 14 C] lactose in biological fluids is described. It is based on the enzymic removal of the 1- 14 C atom of lactose as [ 14 C] carbon dioxide, using commercially available enzymes. The assay involves only one critical addition and the entire reaction can be carried out in a scintillation vial. (author)

  2. DNA methylation by methylbromfenvinfos 14C in in vivo and in vitro experiments

    International Nuclear Information System (INIS)

    Palut, D.; Cybulski, J.

    1979-01-01

    The process of DNA methylation in vitro by methylbromfenvinfos ( 14 C-methyl), an organophosphorous insecticide of Polish production, and methylation of nuclear DNA in vivo after intraperitoneal injection of the insecticide and also after administration of mutagenic alkylating agents: methanomethyl sulphonate 14 C, and N,N-dimethylnitrosoamine 14 C, were studied. (author)

  3. Disposition of [14C]γ-cyclodextrin in germ-free and conventional rats

    NARCIS (Netherlands)

    Bie, A.T.H.J. de; Ommen, B. van; Bär, A.

    1998-01-01

    The absorption, disposition, metabolism, and excretion of 14C-labeled γ-cyclodextrin ([14C]γ-CD) was examined in four separate experiments with Wistar rats. In experiment 1, [14C]γ-CD (25 μCi, 600 mg/kg body wt) was administered intravenously to four male and four female conventional rats. In

  4. Bioconcentration of 14 C-Carbofuran and 14 C- Lindane in fresh water Tilapia Nilitica and the bioavailability of their residues to rats

    International Nuclear Information System (INIS)

    Aly, M.A.S.; Afifi, L.M.

    1997-01-01

    Tilapia Nilotica were exposed to 14 C- carbofuran (125 MUg/1) and 14 C - lindane (80 MUg/1) for 96 h. Uptake period followed by 8 days depuration period. The bioconcentration factor (BCF) for carbofuran reached 32.4 at 12 h and 82 for lindane at 48 h. The amount of 14 C-activity found in fish treated with 14 C - carbofuran after the uptake period showed the following descending order: viscera > remaining parts > gills > muscles. In case of 14 C - lindane treated fish the recovered amount followed the order; remaining parts> viscera > gills muscles. During the depuration period, carbofuran residues taken up by fish were eliminated in 2 phases, an initial rapid phase followed by a slower gradual one. However, the rate of elimination in case of lindane was much slower especially during the first 2 days. At the end of the depuration period (8 days), the muscles (edible portion) contained 10% and 58% of 14 C -activity in case of carbofuran and lindane treated groups, respectively. Both insecticides proved to be bioavailable when rats were fed treated fish. Of the administered dose, 44.1% and 53.0% were excreted in urine and feces case of 14 C-carbofuran while in case of 14 C - lindane it was 30.9% and 41.7% for urine and feces, respectively. 2 figs., 2 tabs

  5. Early incorporation and distribution of 14C-photosynthates after 14C-feeding for a brief period in tea plant

    International Nuclear Information System (INIS)

    Hakamata, Katsuhiro

    1981-01-01

    In order to clarify the early incorporation and distribution of 14 C-photosynthetic products in tea plants after 14 C-feeding for a brief period, 14 C-tracer experiments were performed, using the winter leaves, first crop shoots and young tea plants of a cultivar, Yabukita. As the results of the experiment on leaf disks by 14 C-Feeding for one minute, the 14 C-activity in the ethanol soluble fraction distributed in the anionic, cationic and neutral fractions in this order. When the time of feeding was extended to 10 min, the distribution in the cationic fraction decreased, and that in the neutral fraction increased. In the experiment on shoots, after the end of 10 min assimulation, the 14 C-activity in the ethanol soluble fraction distributed in the neutral, cationic and anionic fractions in this order. In course of time, the distribution in the cationic and anionic fractions decreased, and that in the neutral fraction increased. As the results of 14 C-feeding to young tea plants for 2.5 hours, 70 - 95% of the 14 C-activity in the ethanol soluble fraction distributed in the neutral fraction. Sucrose seemed to be the primary and early product of photosynthesis, and might be the principal carbohydrate form of translocation and reserve in tea plants. Raffinose and stachyose played almost the same role as sucrose. (Kako, I.)

  6. THEODORE, a two-step heating system for the EC/OC determination of radiocarbon (14C) in the environment

    International Nuclear Information System (INIS)

    Szidat, S.; Jenk, T.M.; Gaeggeler, H.W.; Synal, H.-A.; Hajdas, I.; Bonani, G.; Saurer, M.

    2004-01-01

    Measurements of 14 C in the organic carbon (OC) and elemental carbon (EC) fractions, respectively, of fine aerosol particles bear the potential to apportion anthropogenic and biogenic emission sources. For this purpose, the system THEODORE (two-step heating system for the EC/OC determination of radiocarbon in the environment) was developed. In this device, OC and EC are transformed into carbon dioxide in a stream of oxygen at 340 and 650 deg. C, respectively, and reduced to filamentous carbon. This is the target material for subsequent accelerator mass spectrometry (AMS) 14 C measurements, which were performed on sub-milligram carbon samples at the PSI/ETH compact 500 kV AMS system. Quality assurance measurements of SRM 1649a, Urban Dust, yielded a fraction of modern f M in total carbon (TC) of 0.522 ± 0.018 (n=5, 95% confidence level) in agreement with reported values. The results for OC and EC are 0.70 ± 0.05 (n=3) and 0.066 ± 0.020 (n=4), respectively

  7. Measurement of biocarbon in flue gases using 14C

    Energy Technology Data Exchange (ETDEWEB)

    Haemaelaeinen, K.M.; Jungner, H.; Antson, O.; Rasanen, J.; Tormonen, K.; Roine, J. [University of Helsinki, Helsinki (Finland). Radiocarbon Dating Laboratory

    2007-07-01

    A preliminary investigation of the biocarbon fraction in carbon dioxide emissions of power plants using both fossil- and biobased fuels is presented. Calculation of the biocarbon fraction is based on radiocarbon content measured in power plant flue gases. Samples were collected directly from the chimneys into plastic sampling bags. The C-14 content in CO{sub 2} was measured by accelerator mass spectrometry (AMS). Flue gases from power plants that use natural gas, coal, wood chips, bark, plywood residue, sludge from the pulp factory, peat, and recovered fuel were measured. Among the selected plants, there was one that used only fossil fuel and one that used only biofuel; the other investigated plants burned mixtures of fuels. The results show that C-14 measurement provides the possibility to determine the ratio of bio and fossil fuel burned in power plants.

  8. The preparation of 14C, 35S and 13C labelled forms of omeprazole

    International Nuclear Information System (INIS)

    Crowe, A.M.; Ife, R.J.; Mitchell, M.B.; Saunders, D.

    1986-01-01

    The syntheses of [benzimidazole-2- 14 C]omeprazole, [benzimidazole-2- 13 C]omeprazole, [ 35 S]omeprazole and [2-pyridyl- 14 C-methyl]-omeprazole are described. The first three compounds were prepared from the appropriate isotopically labelled carbon disulphide. The key step in the synthesis of [2-pyridyl- 14 C-methyl]omeprazole is nucleophilic alkylation of a l-ethoxypyridinium salt using [ 14 C]methyl magnesium idodide. This is the first time that a reaction of this type has been used to prepare a 2-[methyl- 14 C]methylpyridine. (author)

  9. Preparation of /sup 14/C, /sup 35/S and /sup 13/C labelled forms of omeprazole

    Energy Technology Data Exchange (ETDEWEB)

    Crowe, A.M.; Ife, R.J.; Mitchell, M.B.; Saunders, D.

    1986-01-01

    The syntheses of (benzimidazole-2- /sup 14/C)omeprazole, (benzimidazole-2-/sup 13/C)omeprazole, (/sup 35/S)omeprazole and (2-pyridyl- /sup 14/C-methyl)-omeprazole are described. The first three compounds were prepared from the appropriate isotopically labelled carbon disulphide. The key step in the synthesis of (2-pyridyl- /sup 14/C-methyl)omeprazole is nucleophilic alkylation of a l-ethoxypyridinium salt using (/sup 14/C)methyl magnesium idodide. This is the first time that a reaction of this type has been used to prepare a 2-(methyl-/sup 14/C)methylpyridine.

  10. Quartz OSL Dating of the loess deposit in the eastern Tibetan Plateau and its environment implications since the Last Glaciation

    Science.gov (United States)

    Yang, S.; Cheng, T.; Liu, W.; Fang, X.

    2017-12-01

    Loess deposit is widespread in the Chuanxi Plateau, the eastern Tibetan Plateau, which is a critical archive for understanding the aeolian process, the evolution of the westerly and the environment changes on the Plateau. Previous studies have shown its aeolian origin, and mainly transported by wind from the western part of the Tibetan Plateau. However, the aeolian processes of the loess and its environment implications are not well understood mainly due to lack of detailed age controls. We carry out a combined quartz optically stimulated luminescence (OSL) dating and accelerator mass spectrometry radiocarbon dating (AMS 14-C) for the loess deposits in Garzê and Jinchuan. The results indicate that the quartz OSL dating can provide reliable age controls for the loess-paleosol sequences from the Chuanxi Plateau, showing the potential of OSL to date loess in the high altitude region. The results indicate that the OSL ages are in agreement with the observed stratigraphy in the field. The constructed OSL and AMS 14-C chronology of the Garzê loess reveals that the widespread loess in Ganzi Region deposited since the Last Glacial. The dust accumulation is rapid during marine isotope stage (MIS) 3 and 2, and a relative low accumulation rate in the Holocene, which may related with the desertification processes of the inner Tibetan Plateau.

  11. Production method of 14C-labelled cytosine and its derivatives

    International Nuclear Information System (INIS)

    Filip, J.; Hradec, H.

    1987-01-01

    Initial raw material for the production of labelled cytosine are available compounds of uracil and its derivatives labelled with 14 C. Uracil reacts with dioxane and phosphorus pentasulfide in the presence of 4-thiouracil labelled with 14 C. The intermediate product is heated up in the presence of aqueous ammonium hydroxide. The 14 C-labelled cytosine obtained is separated using preparative paper chromatography. Radiochemical purity of the product is higher than 98%. It is thus possible to prepare [2- 14 C]cytosine, [2,4,5- 14 C]cytosine, [U- 14 C]cytosine, [U- 14 C]5-methyl cytosine and other derivatives of high molar activities. The advantages of the method include a reaction without intermediate product separation and high chemical and radiochemical yields. (E.S.)

  12. Seasonal variations of {sup 14}C and δ{sup 13}C for cave drip waters in Ryugashi Cave, Shizuoka Prefecture, central Japan

    Energy Technology Data Exchange (ETDEWEB)

    Minami, Masayo, E-mail: minami@nendai.nagoya-u.ac.jp [Center for Chronological Research, Nagoya University, Nagoya 464-8602 (Japan); Kato, Tomomi [Graduate School of Environmental Studies, Nagoya University, Nagoya 464-8601 (Japan); Horikawa, Keiji [Department of Environmental Biology and Chemistry, Toyama University, Toyama 930-8555 (Japan); Nakamura, Toshio [Center for Chronological Research, Nagoya University, Nagoya 464-8602 (Japan)

    2015-11-01

    Speleothem {sup 14}C has recently emerged as a potentially powerful proxy for hydrology changes in comparison with atmospheric {sup 14}C calibration curve, rather than as a direct dating tool, apart from a time marker using bomb peak of {sup 14}C. Some possible causes for the relationship between speleothem {sup 14}C content (or dead carbon fraction: DCF) and karst hydrology have been proposed, such as changes in temperature, precipitation, drip water flow dynamics, cave air ventilation, soil air pCO{sub 2}. In this study, we investigated seasonal variation in {sup 14}C and δ{sup 13}C of drip water in Ryugashi Cave, Shizuoka Prefecture, central Japan, to examine the causes of the {sup 14}C and δ{sup 13}C variations in a speleothem. The results show that different {sup 14}C concentrations and δ{sup 13}C values of drip water from the Ryugashi Cave, were exhibited at different sites of the Caves No. 1, No. 3, and No. 4, which have different temperature, air pCO{sub 2}, and flow paths. Further, the {sup 14}C and δ{sup 13}C of drip waters showed seasonal variations at all sites, which were lower in fall and winter, and higher in spring and summer, though the extent of the variations was different among the sites. The {sup 14}C in drip waters tended to be correlated with the drip rates: {sup 14}C tended to be higher in drip waters with higher drip rates, and also correlated with rainfall amount around the Ryugashi Cave, especially for the drip waters in Cave No. 3, which are considered to have simpler flow paths. The increase in rainfall amount could bring the increase in drip rate of drip water, and then the decrease in interaction between solution and karst, resulting in {sup 14}C increase (DCF decrease) in drip water. Accordingly, the reconstruction of precipitation could be performed using {sup 14}C variation in a speleothem formed by drip water with simple flow dynamics.

  13. Measurement of {sup 14}C/{sup 12}C ratios in plant samples that were affected by the Fukushima nuclear accident

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, Risa; Inoue, Aki; Muramatsu, Yasuyuki [Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo, 171-8588 (Japan); Matsuzaki, Hiroyuki [The University of Tokyo, Micro Analysis Laboratory, Tandem Accelerator, 2-11-16 Yayoi, Bunkyo-ku, Tokyo, 113-0032 (Japan)

    2014-07-01

    In nature, {sup 14}C is produced by cosmic ray reactions in the upper atmosphere, and its production is influenced by the flux of cosmic rays. This nuclide is also released into the atmosphere by anthropogenic sources such as nuclear weapons testing and a nuclear accident. The produced {sup 14}C immediately becomes {sup 14}CO{sub 2} and it is absorbed by plants through photosynthesis. Therefore, plants are reflected by atmospheric {sup 14}C levels at that time. Although there are many papers reporting the release of several nuclides by the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident occurred in March, 2011, it is not clear whether appreciable amounts of {sup 14}C were released into the environment due to the accident. In this study, we focus on {sup 14}C levels in plant samples collected from several locations in Fukushima Prefecture (Okuma, Namie, Iitate, and Fukushima-city) and examine the possible influence on the {sup 14}C revels in plants. Since cedars and pines are evergreen, the leaves should have been contaminated at the time of the accident. We analyzed old leaves, which were grown before the accident, and new leaves, which were grown after the accident. Both old and new leaves were collected in the same branch. In order to compare delta {sup 14}C values in leaves collected from Fukushima Prefecture with background values, we have used plant samples collected from remote areas such as Chiba and Niigata Prefectures. The samples were dried, pulverized in a blender and homogenized. Then samples were placed between copper oxide wires in a quarts tube, burned and oxidized. The produced CO{sub 2} mixed gases were purified in a vacuum line. To prepare a graphite target for AMS, the purified CO{sub 2} was reduced. {sup 14}C/{sup 12}C ratio in the graphite was measured by AMS at the University of Tokyo or Japan Atomic Energy Agency. Analytical results showed that delta {sup 14}C values in plant samples collected from the highly contaminated areas such as

  14. Mass spectrometric detection of radiocarbon for dating applications

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-01-15

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

  15. Mass spectrometric detection of radiocarbon for dating applications

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  16. Mass spectrometric detection of radiocarbon for dating applications

    Science.gov (United States)

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

    2013-01-01

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

  17. Compact AMS System At Yamagata University

    Science.gov (United States)

    Tokanai, Fuyuki; Kato, Kazuhiro; Anshita, Minoru; Izumi, Akihiro; Sakurai, Hirohisa; Saito, Tsugio

    2011-06-01

    A new compact accelerator mass spectrometry (AMS) system has been installed in the Kaminoyama research institute at Yamagata University. The AMS system is based on a 0.5 MV Pelletron accelerator developed by National Electrostatics Corp. The performance of the system was investigated using C series samples (C1-C8), standard samples (HOxII), and reagent graphite without any chemical treatment. The precision of 14C measurements for the standard samples is typically higher than 0.3%. The ratio of 14C to 12C is less than 6×10-16 for the reagent graphite. In this paper, we present the performance of the new compact AMS system, as well as of the fully automated 20-reactor graphite lines equipped at the research institute.

  18. {Delta}{sup 14}C level of annual plants and fossil fuel derived CO{sub 2} distribution across different regions of China

    Energy Technology Data Exchange (ETDEWEB)

    Xi, X.T.; 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); Zhou, L.P. [Laboratory for Earth Surface Processes, Department of Geography, Peking University, Beijing 100871 (China); Liu, K.X., E-mail: kxliu@pku.edu.cn [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

    The {sup 14}C level in annual plants is a sensitive tracer for monitoring fossil fuel derived CO{sub 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 {sup 14}C/{sup 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{sub 2} was estimated by comparing the measured {Delta}{sup 14}C values of corn leave samples to background atmospheric {Delta}{sup 14}C level. The influences of topography, meteorological conditions and carbon cycling processes on the fossil fuel derived CO{sub 2} concentration are considered when interpreting the data. Our results show a clear association of the low {Delta}{sup 14}C values with regions where human activities are intensive.

  19. Formation and bio release of bound residues of [14 C]-lindane and [14 C]-parathion in two Brazilian soils

    International Nuclear Information System (INIS)

    Andrea, M.M. de.

    1992-01-01

    This work studied the extractable and bound residues formation of 14 C-lindane and 14 C-parathion immediately after application and after 3 months of interaction of the pesticides with the soils. Metabolism, bio release, and the possible bioavailability of bound residues were studied by employing bio meter flasks which allowed a relative comparison of the behaviour of the two different 14 C-pesticides, by a balance of the applied or present radiocarbon in the soils after the bio tests. (author)

  20. Radiocarbon dating of lake sediments

    OpenAIRE

    Pocevičius, Matas

    2016-01-01

    Matas Pocevičius, Radiocarbon dating of lake sediments, bachelor thesis, Vilnius University, Faculty of Physics, Department of General Physics and Spectroscopy, physics, Vilnius, 45 p., 2016. The aim of this study is to evaluate the possibility of radiocarbon dating application for Tapeliai lake bottom sediments. The literature review discusses topics related to accelerator mass spectrometry, principles of radiocarbon formation, importance of nuclear fallout for 14C, possible applications of ...

  1. Multi-nuclide AMS performances at MALT

    Science.gov (United States)

    Matsuzaki, Hiroyuki; Nakano, Chuichiro; Tsuchiya, Yoko (Sunohara); Kato, Kazuhiro; Maejima, Yuji; Miyairi, Yosuke; Wakasa, Sachi; Aze, Takahiro

    2007-06-01

    MALT (Micro Analysis Laboratory, Tandem accelerator, The University of Tokyo) is a service and research facility for elemental and isotopic micro-analysis using a tandem accelerator, which was constructed in 1991-1993 and has been in operation since 1994. Since then, AMS, NRA and PIXE systems have been developed and highly refined. The accelerator of MALT is a 5UD Pelletron™ tandem van de Graaf (produced by National Electrostatics Corporation, USA) and maximum 5 MV voltage is available. MALT is equipped with two MC-SNICS ion sources (one of them dedicated for 14C-AMS), a sequential injection system and multi-Faraday cup systems. These equipment are all indispensable for a high precision and high efficiency AMS system. At MALT, high quality AMS of 7Be, 10Be, 14C, 26Al has been available. Recently, a 36Cl-AMS system using a gas-filled magnet was also greatly refined, and a new 129I-AMS system was developed and shows good performance. Now MALT is the only facility with multi-nuclide AMS in the Asian area. Over 40 projects are running at MALT every year. The total accelerator operation time in the 2004 season was 6363 h. In November 2004, the total operation time of the pelletron chain system since the construction of MALT went over 40,000 h without replacement.

  2. Distribution and biodegradability of 14C-residues bound in various soil fractions after treatment of the soil with model 14C-chemicals

    International Nuclear Information System (INIS)

    Scheunert, I.; Meer-Bekk, C. ter; Korte, F.

    1986-01-01

    The long-term fate of 14 C-labelled 4-chloroaniline, 2,4,6-trichloroaniline, 2,4,6-trichlorophenol and trichloroethylene in soil was studied under field conditions. As a natural reference compound, 14 C-glucose was also studied. Most of the trichloroethylene applied was lost by volatilization and/or degradation during a 25-week period. The soils were exhaustively extracted with methanol and then re-extracted with acetate buffer solutions. The extracted soils were fractionated into humic acid, fulvic acid, humin and inorganic fractions. With the exception of 2,4,6-trichloroaniline the bound residues were more than 31% of the amount of radiocarbon initially applied. Insoluble residues of the natural compound glucose were bound preferentially in the inorganic fraction, whereas 14 C of the four xenobiotics was concentrated more in the humic acid fraction, with the portion increasing in the order: glucose 14 C in soil is present in a metabolized form. (author)

  3. A study on the pharmacokinetics of [1-14C]-hexanoyl aldehyde sodium bi-sulfite (14C-HASB) in mice

    International Nuclear Information System (INIS)

    Li Guanhong; Gui Zhining

    1991-01-01

    After a single intravenous injection of [1- 14 C]-hexanoyl aldehyde sodium bi-sulfite (HASB), the blood radioactivity time course curve fitted well a two-compartment open model. The radioactivity distributed widely in the body, with the concentrations in liver and kidneys markedly higher than in blood and other tissues. Except in kidneys and liver, the radioactivities in tissues decreased to quite low levels 4 h after administration. The radioactivity in tumors were relatively lower. Thin layer chromatographic (TLC) analyses indicated that most of radioactivity in serum was in the form of unchanged 14 C-HASB and the drug was metabolized rapidly after passing into some tissue cells in vivo. The major routes of elimination were found to be via expiration with 26.76% of the 14 C recovered as carbon dioxide in 3 h and via urine with 14.6% of the 14 C recovered in 24 h mainly in the form of metabolites

  4. {sup 14}C emission from Swedish nuclear power plants and its effect on the {sup 14}C levels in the environment

    Energy Technology Data Exchange (ETDEWEB)

    Stenstroem, K.; Erlandsson, Bengt; Hellborg, R.; Kiisk, M.; Persson, Per [Lund Univ. (Sweden). Dept. of Nuclear Physics; Mattsson, Soeren; Thornberg, C. [Lund Univ., Malmoe (Sweden). Dept. of Radiation Physics; Skog, G. [Lund Univ. (Sweden). Dept. of Quaternary Geology

    2000-02-15

    The radionuclide {sup 14}C is produced in all types of nuclear reactors mainly by neutron induced reactions in oxygen ({sup 17}O), nitrogen ({sup 14}N) and carbon ({sup 13}C). Part of the {sup 14}C created is continuously released during normal operation as airborne effluents in various chemical forms (such as CO{sub 2}, CO and hydrocarbons) to the surroundings. Because of the biological importance of carbon and the long physical half-life of {sup 14}C, it is of interest to measure the releases and their incorporation into living material. The {sup 14}C activity concentrations in annual tree rings and air around two Swedish nuclear power plants (Barsebaeck and Forsmark) as well as the background {sup 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 {sup 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 {sup 14}C measurements of air, vegetation and annual tree rings around the two Swedish nuclear power plants show very low enhancements of {sup 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 {sup 14}C from the reactors to the environment is so small that it is difficult to separate it from the prevailing background levels of {sup 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

  5. {8-14C}-Adenine and {1-14C}-isopentenyl pyrophosphate - precursors for root-produced cytokinins in the tomato (Lycopersicon esculentum mill.)

    International Nuclear Information System (INIS)

    Dickinson, J.R.

    1985-01-01

    Following the detection of reasonable levels of biologically active cytokinin-like compounds in one-month-old tomato plants, the possible involvement of {8- 14 C}-adenine and {1- 14 C}-isopentenyl pyrophosphate in the biosynthetic pathway leading to an accumulation of free zeatin derivatives, was studied. Intact tomato plants were used for a time-course study involving the uptake of {8- 14 C}-adenine and the tentative identification of compounds into which the 14 C became incorporated. Using high performance liquid chromatography, radioactive trans-zeatin was identified as being present in the Dowex 50 root extract. The 12-hour time interval was used and the roots of the tomato plants were immersed in a more heavily radiolabelled medium. Modified separation techniques were used to achieve enhanced radioactivity recovery rates. This experiment demonstrated the presence of relatively high levels of tentatively identified radioactive zeatin in the Dowex 50 root and stem extracts. Radioactivity in the aqueous extracts was found not to be contributed by cytokinin nucleotides. A final experiment was carried out using decapitated root systems to determine if the root tissue alone could be implicated in the synthesis of cytokinins. Decapitated tomato root systems were supplied with either {8- 14 C}-adenine or {1- 14 C}-isopentenyl pyrophosphate. The ratio of incorporation of {1- 14 C}-isopentenyl pyrophosphate into identified cytokinins was higher than for {8- 14 C}-adenine. It was concluded that both adenine and isopentenyl pyrophosphate are involved in the biosynthetic pathway leading to an accumulation of free zeatin derivatives in tomato roots

  6. Radiocarbon dating and compositional analysis of pre-Columbian human bones

    International Nuclear Information System (INIS)

    Andrade, E.; Solís, C.; Canto, C.E.; Lucio, O.G. de; Chavez, E.; Rocha, M.F.; Villanueva, O.; Torreblanca, C.A.

    2014-01-01

    Analysis of ancient human bones found in “El Cóporo”, an archaeological site in Guanajuato, Mexico; were performed using a multi techniques scheme: 14 C radiocarbon dating, IBA (Ion Beam Analysis), SEM-EDS (Scanning Electron Microscope Energy Dispersive X-ray Spectroscopy). We measured the elemental composition of the bones, especially some with a superficial black pigmentation. Soil samples collected from the burial place were also analyzed. The 14 C dating was performed with a new High Voltage Europe 1 MV Tandentron Accelerator Mass Spectrometer (AMS) recently installed in the IFUNAM (Instituto de Física, Universidad Nacional Autónoma de México). The radiocarbon dating allowed us to determine the date of death of the individual in a period between the year 890 and 975 AD, which is consistent with the late period of the Cóporo civilization. The element sample analysis of bones with the surface black pigmentation show higher levels of Fe, Mn and Ba compared when bone’s black surface was mechanically removed. These three elements were found in soil samples from the skeleton burial place. These results indicate more likely that the bone black coloration is due to a postmortem alteration occurring in the burial environment

  7. Radiocarbon dating and compositional analysis of pre-Columbian human bones

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, E., E-mail: andrade@fisica.unam.mx [Instituto de Física, Universidad Nacional Autónoma de México, Apartado Postal 20-364, 01000 México D.F. (Mexico); Solís, C.; Canto, C.E.; Lucio, O.G. de [Instituto de Física, Universidad Nacional Autónoma de México, Apartado Postal 20-364, 01000 México D.F. (Mexico); Chavez, E. [ESIME-Z, Instituto Politécnico Nacional, ALM Zacatenco, 07738 México D.F. (Mexico); Rocha, M.F.; Villanueva, O.; Torreblanca, C.A. [Centro INAH Zacatecas, Miguel Auza No. 205, Col. Centro, Zacatecas/Zacatecas CP 98000 (Mexico)

    2014-08-01

    Analysis of ancient human bones found in “El Cóporo”, an archaeological site in Guanajuato, Mexico; were performed using a multi techniques scheme: {sup 14}C radiocarbon dating, IBA (Ion Beam Analysis), SEM-EDS (Scanning Electron Microscope Energy Dispersive X-ray Spectroscopy). We measured the elemental composition of the bones, especially some with a superficial black pigmentation. Soil samples collected from the burial place were also analyzed. The {sup 14}C dating was performed with a new High Voltage Europe 1 MV Tandentron Accelerator Mass Spectrometer (AMS) recently installed in the IFUNAM (Instituto de Física, Universidad Nacional Autónoma de México). The radiocarbon dating allowed us to determine the date of death of the individual in a period between the year 890 and 975 AD, which is consistent with the late period of the Cóporo civilization. The element sample analysis of bones with the surface black pigmentation show higher levels of Fe, Mn and Ba compared when bone’s black surface was mechanically removed. These three elements were found in soil samples from the skeleton burial place. These results indicate more likely that the bone black coloration is due to a postmortem alteration occurring in the burial environment.

  8. AixMICADAS, the accelerator mass spectrometer dedicated to {sup 14}C recently installed in Aix-en-Provence, France

    Energy Technology Data Exchange (ETDEWEB)

    Bard, Edouard, E-mail: bard@cerege.fr [CEREGE, Aix-Marseille University, CNRS, IRD, Collège de France, Technopôle de l’Arbois, BP 80, F-13545 Aix-en-Provence (France); Tuna, Thibaut; Fagault, Yoann; Bonvalot, Lise [CEREGE, Aix-Marseille University, CNRS, IRD, Collège de France, Technopôle de l’Arbois, BP 80, F-13545 Aix-en-Provence (France); Wacker, Lukas; Fahrni, Simon; Synal, Hans-Arno [Laboratory of Ion Beam Physics, ETH Zurich, 8093 Zurich (Switzerland)

    2015-10-15

    A compact AMS system dedicated to measuring {sup 14}C in ultra-small samples was installed at the CEREGE in Aix-en-Provence at the end of March 2014, together with an automated graphitization system. AixMICADAS operates at around 200 kV with carbon ion stripping in helium leading to a transmission of about 47%. The hybrid ion source works with graphite targets and CO{sub 2} gas. It is coupled to a versatile gas interface system that ensures stable gas measurements from different sources: a cracker for CO{sub 2} in glass ampoules, an elemental analyzer for combusting organic matter and an automated system to handle carbonate by wet chemistry. The analyses performed during the first half-year of operation show that a precision of about 2‰ is reached on modern samples of about 1 mg of carbon. Measurements of IAEA reference materials of various {sup 14}C ages show a good agreement with consensus values. Direct measurements of geological graphites indicate a machine background equivalent to an age of 68,000 years BP. AixMICADAS is thus limited solely by the {sup 14}C contamination of samples in the field and in the laboratory. The performances of the gas ion source and its gas interface system were tested with two CO{sub 2} production units: the elemental analyzer and the automated carbonate hydrolysis unit. These tests show that samples ranging between 10 and 100 μg C can produce a {sup 12}C{sup −} ion beam of the order of 10–15 μA during time spans ranging from 3 to 30 min depending on the sample mass. Coupling the automated hydrolysis system to the gas ion source of AixMICADAS, enables us to develop a method involving sequential leaching of carbonate samples with direct {sup 14}C measurements of the leached fractions and the residual sample. The main advantage is that all of steps leaching and hydrolysis are performed in the same vial for a particular sample. A sequential leaching was applied to a young carbonate sample (ca. 6600 years BP) whose {sup 14}C age

  9. Alternatives to reduce 14C emissions in the reprocessing of HTR fuel elements

    International Nuclear Information System (INIS)

    Schmidt, P.C.

    1979-01-01

    The interest of the public and of experts has increasingly focused on the formation of 14 C in nuclear reactors and its release from reactors and reprocessing plants. The paper attempts an experimental check of the validity of theoretical estimations concerning 14 C production rates. In particular, the applicability of the 14 C analysis in irradiated LWR pellets is checked and transferred to HTR fuel concepts. Statements on the 14 C content in matrix graphite, coating, and fuel make it possible to determine those process steps in which 14 C release is highest. Possibilities to reduce 14 C emissions by improved fuel element production technologies and by mechanical separation of graphite before combustion are theoretically estimated. (orig./GL) [de

  10. Study on 14C content in post-irradiation graphite spheres of HTR-10

    International Nuclear Information System (INIS)

    Wang Shouang; Pi Yue; Xie Feng; Li Hong; Cao Jianzhu

    2014-01-01

    Since the production mechanism of the 14 C in spherical fuel elements was similar to that of fuel-free graphite spheres, in order to obtain the amount of 14 C in fuel elements and graphite spheres of HTR-10, the production mechanism of the 14 C in graphite spheres was studied. The production sources of the 14 C in graphite spheres and fuel elements were summarized, the amount of 14 C in the post-irradiation graphite spheres was calculated, the decomposition techniques of graphite spheres were compared, and experimental methods for decomposing the graphite spheres and preparing the 14 C sample were proposed. The results can lay the foundation for further experimental research and provide theoretical calculations for comparison. (authors)

  11. High-resolution OSL chronology of a sediment core from Lake Nam Co on the southern Tibetan Plateau: Comparison with radiocarbon dating

    Science.gov (United States)

    Long, Hao; Shen, Ji; Haberzettl, Torsten; Fuchs, Markus; Frechen, Manfred; Wang, Junbo

    2013-04-01

    Numerous studies on lake sediment cores from the Tibetan Plateau aimed to reconstruct spatial and temporal changes of the late Glacial and Holocene monsoon variations, which are characterized by fluctuations in precipitation and expansion of monsoonal air masses across the Plateau. Accurate and reliable dating of lacustrine deposits is of crucial importance in both the reconstruction of palaeolake and palaeoclimate evolution and the understanding of the mechanisms for climate changes, especially abrupt changes of regional-hemispheric hydrological circulation. Radiocarbon dating is the most commonly used method for establishing chronologies of lake sediments. However, 14C dating of such sediments could be problematic due to the lack of organic matter or a reservoir effect, which appears common in radiocarbon dating of lacustrine sediments from the Tibetan Plateau. In this study, ca. 10.5 m long core (NC core) was retrieved from the water depth of 93 m at Nam Co Lake, which is the second largest saline lake in China, located on the southern Tibetan Plateau. For this core, high-resolution samples (23 samples) were obtained for optically stimulated luminescence (OSL) dating. Quartz of fine-grain (4-11 μm) fraction were extracted from this samples for OSL dating, which is compared with the 14C chronology of NC core based on accelerator mass spectrometry (AMS) dating of bulk organic matter of 22 samples. The sample from the top of NC core was dated to approximate zero age, indicating the sediments bleached well before deposition. Luminescence behaviors of the study samples further confirmed the robustness of OSL ages. Comparison between OSL and 14C ages suggested that: (1) two kinds of ages are in agreement within error from top to 1.8 m, (2) from 1.8 m to the base of NC core, the 14C ages show a general trend to ca. 4 ka higher ages than the OSL ages. Although 14C dating overestimate the ages from 1.8 m to base, they still show the general trend in sedimentation rate

  12. Synthesis of 20-14C 3β-hydroxy-5β-pregnan-20-one

    International Nuclear Information System (INIS)

    Garraffo, H.M.; Gros, E.G.

    1982-01-01

    20 - 14 C 3β-hydroxy-5β-pregnan-20-one was synthesised by condensing 3β-acetoxy-5β-androstan-17-one with potassium 14 C cyanide to produce cyanohydrin. This was dehydrated and the resulting unsaturated nitrile treated with methylmagnesiumiodide to produce hydroxypregnenone. Hydrogenation of this gave 14 C 3β-hydroxy-5β-pregnan-20-one. (U.K.)

  13. Atmospheric 14C variations derived from tree rings during the early Younger Dryas

    Science.gov (United States)

    Hua, Quan; Barbetti, Mike; Fink, David; Kaiser, Klaus Felix; Friedrich, Michael; Kromer, Bernd; Levchenko, Vladimir A.; Zoppi, Ugo; Smith, Andrew M.; Bertuch, Fiona

    2009-12-01

    Atmospheric radiocarbon variations over the Younger Dryas interval, from ˜13,000 to 11,600 cal yr BP, are of immense scientific interest because they reveal crucial information about the linkages between climate, ocean circulation and the carbon cycle. However, no direct and reliable atmospheric 14C records based on tree rings for the entire Younger Dryas have been available. In this paper, we present (1) high-precision 14C measurements on the extension of absolute tree-ring chronology from 12,400 to 12,560 cal yr BP and (2) high-precision, high-resolution atmospheric 14C record derived from a 617-yr-long tree-ring chronology of Huon pine from Tasmania, Australia, spanning the early Younger Dryas. The new tree-ring 14C records bridge the current gap in European tree-ring radiocarbon chronologies during the early Younger Dryas, linking the floating Lateglacial Pine record to the absolute tree-ring timescale. A continuous and reliable atmospheric 14C record for the past 14,000 cal yr BP including the Younger Dryas is now available. The new records indicate that the abrupt rise in atmospheric Δ 14C associated with the Younger Dryas onset occurs at ˜12,760 cal yr BP, ˜240 yrs later than that recorded in Cariaco varves, with a smaller magnitude of ˜40‰ followed by several centennial Δ 14C variations of 20-25‰. Comparing the tree-ring Δ 14C to marine-derived Δ 14C and modelled Δ 14C based on ice-core 10Be fluxes, we conclude that changes in ocean circulation were mainly responsible for the Younger Dryas onset, while a combination of changes in ocean circulation and 14C production rate were responsible for atmospheric Δ 14C variations for the remainder of the Younger Dryas.

  14. Dissipation and leaching of 14C-monocrotophos in soil columns

    International Nuclear Information System (INIS)

    Vig, K.; Singh, D.K.; Agarwal, H.C.

    2001-01-01

    Dissipation and leaching of 14 C-monocrotophos was studied in the field. Two sets of PVC cylinders were used - one set received only 14 C monocrotophos and the other received 14 C-monocrotophos along with dimethoate, deltamethrin, endosulfan, cypermethrin and 1.06 mg unlabelled monocrotophos. Both setups showed a similar pattern of dissipation with a half-life of 277.2 days. Leaching of monocrotophos was observed into the 30cm soil layer. (author)

  15. Evolution of dissolved inorganic carbon in groundwater recharged by cyclones and groundwater age estimations using the 14C statistical approach

    Science.gov (United States)

    Meredith, K. T.; Han, L. F.; Cendón, D. I.; Crawford, J.; Hankin, S.; Peterson, M.; Hollins, S. E.

    2018-01-01

    The Canning Basin is the largest sedimentary basin in Western Australia and is located in one of the most cyclone prone regions of Australia. Despite its importance as a future resource, limited groundwater data is available for the Basin. The main aims of this paper are to provide a detailed understanding of the source of groundwater recharge, the chemical evolution of dissolved inorganic carbon (DIC) and provide groundwater age estimations using radiocarbon (14CDIC). To do this we combine hydrochemical and isotopic techniques to investigate the type of precipitation that recharge the aquifer and identify the carbon processes influencing 14CDIC, δ13CDIC, and [DIC]. This enables us to select an appropriate model for calculating radiocarbon ages in groundwater. The aquifer was found to be recharged by precipitation originating from tropical cyclones imparting lower average δ2H and δ18O values in groundwater (-56.9‰ and -7.87‰, respectively). Water recharges the soil zone rapidly after these events and the groundwater undergoes silicate mineral weathering and clay mineral transformation processes. It was also found that partial carbonate dissolution processes occur within the saturated zone under closed system conditions. Additionally, the processes could be lumped into a pseudo-first-order process and the age could be estimated using the 14C statistical approach. In the single-sample-based 14C models, 14C0 is the initial 14CDIC value used in the decay equation that considers only 14C decay rate. A major advantage of using the statistical approach is that both 14C decay and geochemical processes that cause the decrease in 14CDIC are accounted for in the calculation. The 14CDIC values of groundwater were found to increase from 89 pmc in the south east to around 16 pmc along the groundwater flow path towards the coast indicating ages ranging from modern to 5.3 ka. A test of the sensitivity of this method showed that a ∼15% error could be found for the oldest

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

    International Nuclear Information System (INIS)

    Nakamura, Toshio; Nakai, Nobuyuki; Furukawa, Michiaki

    1990-01-01

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

  17. The clinical value of 14C-urea breath test for diagnosis of helicobacter pylori infection

    International Nuclear Information System (INIS)

    Zhang Shuwen; Zhang Yongxian; Zhang Jinming; Ding Yong; Shao Mingzhe; Liu Zilai; Tian Jiahe

    2003-01-01

    The purpose of this study is to evaluate a rapid microdose 14 C-urea breath test ( 14 C-UBT) with a simplified protocol for detecting the infection of helicobacter pylori (HP). 244 fasting patients with upper gastrointestinal symptoms undergo the 14 C-UBT and 124 cases appear positive. 89 patients of those undergo upper gastrointestinal endoscopy and confirmed as HP infection. The sensitivity and specificity of the 14 C-UBT is 100% when compared with the endoscopy. The test has good diagnostic accuracy with minimal radiation exposure and low cost. Thus, the test is reliable, safe, convenient and cost-effective to clinical use

  18. Effect of Cooking on 14C-Chloropyrifos Residues in Stored Faba Beans

    International Nuclear Information System (INIS)

    Mahdy, F.

    2006-01-01

    The effect of cooking on the amount and nature of 14 C-chloropyrifos residues in stored vicia faba beans was studied. faba beans treated with (ethyl-1- 14 C) chloropyrifos insecticide at a dose 15 and 45 mg insecticide/kg seeds and stored for 30 weeks had 50-54% of the actual applied doses inside the grains in the form of extractable and bound 14 C- chloropyrifos residues. Extractable residues in cooked beans included, in addition to the parent insecticide O-analogue, desethyl chloropyrifos and 3,5,6-trichloro pyridinol, as main degradation products of 14 C-chloropyrifos

  19. Study on transference of assimilate in filling summer maize using isotope 14C

    International Nuclear Information System (INIS)

    Fan Zhongxue; Wang Pu; Liang Zhenxing

    2001-01-01

    The dynamic of assimilate transference from the ear leaf to grain during effective grain filling stage was studied by 14 C tracer. The results showed that the rates of assimilate transportation out of the ear leaf and transference to grain changed very fast. The rate was very big in 4 - 6 hour just after 14 C feeding and decreased with time. The grain which accumulated 14 C-assimilate in a higher rate and got much more 14 C-assimilate in fixed time could develop into larger size

  20. Atmospheric Fossil Fuel CO2 Tracing By 14C In Some Chinese Cities

    Science.gov (United States)

    Zhou, W.; Niu, Z.; Zhu, Y., Sr.

    2016-12-01

    CO2 plays an important role in global climate as a primary greenhouse gas in the atmosphere. Moreover, it has been shown that more than 70% of global fossil fuel CO2 (CO2ff) emissions are concentrated in urban areas (Duren and Miller, 2012). Our study focuses on atmospheric CO2ff concentrations in 15 Chinese cities using accelerator mass spectrometer (AMS) to measure 14C. Our objectives are: (1) to document atmospheric CO2ff concentrations in a variety of urban environments, (2) to differentiate the spatial-temporal variations in CO2ff among these cities, and (3) to ascertain the factors that control the observed variations. For about two years (winter 2014 to winter 2016), the CO2ff concentrations we observed from all sites varied from 5.1±4.5 ppm to 65.8±39.0 ppm. We observed that inland cities display much higher CO2ff concentrations and overall temporal variations than coastal cities in winter, and that northern cities have higher CO2ff concentrations than those of southern cities in winter. For inland cities relatively high CO2ff values are observed in winter and low values in summer; while seasonal variations are not distinct in the coastal cities. No significant (p > 0.05) differences in CO2ff values are found between weekdays and weekends as was shown previously in Xi'an (Zhou et al., 2014). Diurnal CO2ff variations are plainly evident, with high values between midnight and 4:00 am, and during morning and afternoon rush hours (Niu et al., 2016). The high CO2ff concentrations in northern inland cities in winter results mainly from the substantial consumption of fossil fuels for heating. The high CO2ff concentrations seen in diurnal measurements result mainly from variations in atmospheric dispersion, and from vehicle emissions related to traffic flows. The inter-annual variations in CO2ff in cities could provide a useful reference for local governments to develop policy around the effect of energy conservation and emission reduction strategies.

  1. Radiocarbon dating of glacier ice: overview, optimisation, validation and potential

    Directory of Open Access Journals (Sweden)

    C. Uglietti

    2016-12-01

    of 10 000 years. WIOC 14C dating was not only crucial for interpretation of the embedded environmental and climatic histories, but additionally gave a better insight into glacier flow dynamics close to the bedrock and past glacier coverage. For this the availability of multiple dating points in the deepest parts was essential, which is the strength of the presented WIOC 14C dating method, allowing determination of absolute ages from principally every piece of ice.

  2. Rapid increase in cosmogenic 14C in AD 775 measured in New Zealand kauri trees indicates short-lived increase in 14C production spanning both hemispheres

    Science.gov (United States)

    Güttler, D.; Adolphi, F.; Beer, J.; Bleicher, N.; Boswijk, G.; Christl, M.; Hogg, A.; Palmer, J.; Vockenhuber, C.; Wacker, L.; Wunder, J.

    2015-02-01

    In 2012, Miyake et al. reported a sudden and strong increase of the atmospheric radiocarbon (14C) content in Japanese cedar trees of 1.2% between AD 774 and 775. While their findings were quickly confirmed by a German oak chronology for the Northern Hemisphere (NH), the question remained if the effect was seen in both hemispheres. Here we present the first annually resolved Southern Hemisphere (SH) 14C record spanning the interval AD 760-787, using New Zealand kauri (Agathis australis) chronology wood. An almost identical distinct increase compared to Northern Hemisphere data was observed, suggesting a cosmic event with globally uniform impact as a potential cause for the increase. Deploying a carbon cycle box model a worldwide averaged net 14C production of 2.2 ×108 14C atoms cm-2 was estimated, which is 3.7 times higher than the average annual 14C production. The immediate appearance of the event in tree rings on both hemispheres suggests a short duration event of significantly less than 1 yr.

  3. Effect of tolbutamide on sup 14 C-sodium bicarbonate and sup 14 C-alanine metabolism in isolated rat hepatocytes

    Energy Technology Data Exchange (ETDEWEB)

    Kunjathoor, V.V.; Ye, Y.; Pillai, U.A.; Ferguson, P.W.; Medon, P.J. (Northeast Louisiana Univ., Monroe (United States))

    1990-02-26

    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 {sup 14}C from NaH{sup 14}CO{sub 3} and {sup 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{sup 14}CO{sub 3} or {sup 14}C-alanine. TOLB inhibited the incorporation of C{sup 14} from NaHCO{sub 3} and alanine into glucose by 55 and 56%, respectively. TOLB did not alter the incorporation of C{sup 14} from NaHCO{sub 3} into lactate or pyruvate. TOLB did not affect the incorporation of {sup 14}C from alanine into lactate but produced a pooling of {sup 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.

  4. MIN 14C UBT: A combination of gastric basal transit and 14C-urea breath test for the detection of helicobacter pylori infection in human beings

    International Nuclear Information System (INIS)

    Zubillaga, M.; Oliveri, P.; Calcagno, M.L.; Goldman, C.; Caro, R.; Mitta, A.; Degrossi, O.; Boccio, J.

    1997-01-01

    The purpose of this work is to demonstrate that the 14 C-urea breath test (UBT) performed at different times combined with the study of the gastric basal transit, which evaluates the intragastric displacement of a labeled solution under fasting conditions, has the advantage of being representative of the whole stomach surface and constitutes a non-aggressive test for the detection of H. pylori. This test, which has been called MIN 14 C UBT, is a modification of the conventional 14 C UBT in which low volumes of a solution of 14 C-urea together with 99m Tc-sulfur colloid are administered. The 99m Tc-sulfur colloid is not absorbed in the gastrointestinal tract and has the great advantage of allowing the 'visualization' of the transit of the 14 C-urea within the gastrointestinal tract. This modification allows the simultaneous determination of the production of the 14 CO 2 and the place where this process occurs. The results show that there is a good correlation between the images obtained and the breath samples collected. We found that this test has a sensitivity of 98% and a specificity of 96% for H. pylori detection

  5. Status report on the Zagreb Radiocarbon Laboratory - AMS and LSC results of VIRI intercomparison samples

    Science.gov (United States)

    Sironić, Andreja; Krajcar Bronić, Ines; Horvatinčić, Nada; Barešić, Jadranka; Obelić, Bogomil; Felja, Igor

    2013-01-01

    A new line for preparation of the graphite samples for 14C dating by Accelerator Mass Spectrometry (AMS) in the Zagreb Radiocarbon Laboratory has been validated by preparing graphite from various materials distributed within the Fifth International Radiocarbon Intercomparison (VIRI) study. 14C activity of prepared graphite was measured at the SUERC AMS facility. The results are statistically evaluated by means of the z-score and u-score values. The mean z-score value of 28 prepared VIRI samples is (0.06 ± 0.23) showing excellent agreement with the consensus VIRI values. Only one sample resulted in the u-score value above the limit of acceptability (defined for the confidence interval of 99%) and this was probably caused by a random contamination of the graphitization rig. After the rig had been moved to the new adapted and isolated room, all u-score values laid within the acceptable limits. Our LSC results of VIRI intercomparison samples are also presented and they are all accepted according to the u-score values.

  6. Status report on the Zagreb Radiocarbon Laboratory - AMS and LSC results of VIRI intercomparison samples

    Energy Technology Data Exchange (ETDEWEB)

    Sironic, Andreja [Department of Experimental Physics, Ruder Boskovic Institute, Bijenicka 54, 10000 Zagreb (Croatia); Krajcar Bronic, Ines, E-mail: krajcar@irb.hr [Department of Experimental Physics, Ruder Boskovic Institute, Bijenicka 54, 10000 Zagreb (Croatia); Horvatincic, Nada; Baresic, Jadranka; Obelic, Bogomil; Felja, Igor [Department of Experimental Physics, Ruder Boskovic Institute, Bijenicka 54, 10000 Zagreb (Croatia)

    2013-01-15

    A new line for preparation of the graphite samples for {sup 14}C dating by Accelerator Mass Spectrometry (AMS) in the Zagreb Radiocarbon Laboratory has been validated by preparing graphite from various materials distributed within the Fifth International Radiocarbon Intercomparison (VIRI) study. {sup 14}C activity of prepared graphite was measured at the SUERC AMS facility. The results are statistically evaluated by means of the z-score and u-score values. The mean z-score value of 28 prepared VIRI samples is (0.06 {+-} 0.23) showing excellent agreement with the consensus VIRI values. Only one sample resulted in the u-score value above the limit of acceptability (defined for the confidence interval of 99%) and this was probably caused by a random contamination of the graphitization rig. After the rig had been moved to the new adapted and isolated room, all u-score values laid within the acceptable limits. Our LSC results of VIRI intercomparison samples are also presented and they are all accepted according to the u-score values.

  7. Status report on the Zagreb Radiocarbon Laboratory – AMS and LSC results of VIRI intercomparison samples

    International Nuclear Information System (INIS)

    Sironić, Andreja; Krajcar Bronić, Ines; Horvatinčić, Nada; Barešić, Jadranka; Obelić, Bogomil; Felja, Igor

    2013-01-01

    A new line for preparation of the graphite samples for 14 C dating by Accelerator Mass Spectrometry (AMS) in the Zagreb Radiocarbon Laboratory has been validated by preparing graphite from various materials distributed within the Fifth International Radiocarbon Intercomparison (VIRI) study. 14 C activity of prepared graphite was measured at the SUERC AMS facility. The results are statistically evaluated by means of the z-score and u-score values. The mean z-score value of 28 prepared VIRI samples is (0.06 ± 0.23) showing excellent agreement with the consensus VIRI values. Only one sample resulted in the u-score value above the limit of acceptability (defined for the confidence interval of 99%) and this was probably caused by a random contamination of the graphitization rig. After the rig had been moved to the new adapted and isolated room, all u-score values laid within the acceptable limits. Our LSC results of VIRI intercomparison samples are also presented and they are all accepted according to the u-score values.

  8. Present status of the JNC Tono Geoscience Center AMS system

    Science.gov (United States)

    Itoh, Shigeru; Abe, Masahito; Watanabe, Masato; Nakai, Suguru; Touyama, Hisayo; Xu, Sheng

    2004-08-01

    The present status of the JNC Tono Geoscience Center AMS system (TGC-AMS) and the recent developments for 14C and 10Be are summarized. The preparation system for 14C has been modified to enable the preparation of small samples. The precision for 14C measurements with samples having a carbon mass >0.3 mg was normally within 0.5%. For the 10Be analysis, the detector of the AMS system has been improved by mounting a nitrogen absorber together with Havar windows in order to suppress 10B isobars. The efficient separation of 10B from 10Be was demonstrated by comparing the rest energy spectra of a 10Be standard and a mutually 10Be-free sample material.

  9. Present status of the JNC Tono Geoscience Center AMS system

    Energy Technology Data Exchange (ETDEWEB)

    Itoh, Shigeru E-mail: shigeru@tono.jnc.go.jp; Abe, Masahito; Watanabe, Masato; Nakai, Suguru; Touyama, Hisayo; Xu Sheng

    2004-08-01

    The present status of the JNC Tono Geoscience Center AMS system (TGC-AMS) and the recent developments for {sup 14}C and {sup 10}Be are summarized. The preparation system for {sup 14}C has been modified to enable the preparation of small samples. The precision for {sup 14}C measurements with samples having a carbon mass >0.3 mg was normally within 0.5%. For the {sup 10}Be analysis, the detector of the AMS system has been improved by mounting a nitrogen absorber together with Havar windows in order to suppress {sup 10}B isobars. The efficient separation of {sup 10}B from {sup 10}Be was demonstrated by comparing the rest energy spectra of a {sup 10}Be standard and a mutually {sup 10}Be-free sample material.

  10. Study on the degradation of 14C maneb during the fabrication of concentrated tomato

    International Nuclear Information System (INIS)

    Sennaoui, Z.; Meguenni, H.; Bennaceur, M.

    1992-11-01

    Tomatoes were contaminated with 14C maneb to know the degradation of this fungicide during the technological process of tomato under laboratory conditions. 57,2% of the initial amount of 14C maneb applied was found in the many metabolites ETM, ETU and EU, were found during the technological transformation of tomato

  11. Systemic translocation and metabolism of 14C-metalaxyl in citrus

    International Nuclear Information System (INIS)

    Musumeci, M.R.; Ruegg, E.F.

    1984-01-01

    Systemic uptake and translocation of 14 C-metalaxyl to citrus seedlings from soils (Humic Gley and Yellow Red Latosol) with different physical - chemical properties are studied. Seedlings of Citrus limonia are treated with 14 C-metalaxyl. (M.A.C.) [pt

  12. Pesticides labelled with 14C. Pt. 4: Synthesis of Diuron and Linuron in various positions

    International Nuclear Information System (INIS)

    Volford, J.; Koltai, E.; Kling, F.; Volford, A.

    1996-01-01

    Diuron and Linuron, two herbicides, with very similar structures were labelled in their aromatic ring with 14 C. The yields of the synthesis (starting from Ba 14 CO 3 ) was 8.5% and 4.8%, respectively. Linuron was also labelled with 14 C in its urea group with 33% yield. (author)

  13. Rapid analysis method for the determination of 14C specific activity in irradiated graphite.

    Science.gov (United States)

    Remeikis, Vidmantas; Lagzdina, Elena; Garbaras, Andrius; Gudelis, Arūnas; Garankin, Jevgenij; Plukienė, Rita; Juodis, Laurynas; Duškesas, Grigorijus; Lingis, Danielius; Abdulajev, Vladimir; Plukis, Artūras

    2018-01-01

    14C is one of the limiting radionuclides used in the categorization of radioactive graphite waste; this categorization is crucial in selecting the appropriate graphite treatment/disposal method. We propose a rapid analysis method for 14C specific activity determination in small graphite samples in the 1-100 μg range. The method applies an oxidation procedure to the sample, which extracts 14C from the different carbonaceous matrices in a controlled manner. Because this method enables fast online measurement and 14C specific activity evaluation, it can be especially useful for characterizing 14C in irradiated graphite when dismantling graphite moderator and reflector parts, or when sorting radioactive graphite waste from decommissioned nuclear power plants. The proposed rapid method is based on graphite combustion and the subsequent measurement of both CO2 and 14C, using a commercial elemental analyser and the semiconductor detector, respectively. The method was verified using the liquid scintillation counting (LSC) technique. The uncertainty of this rapid method is within the acceptable range for radioactive waste characterization purposes. The 14C specific activity determination procedure proposed in this study takes approximately ten minutes, comparing favorably to the more complicated and time consuming LSC method. This method can be potentially used to radiologically characterize radioactive waste or used in biomedical applications when dealing with the specific activity determination of 14C in the sample.

  14. Influence of nitrogen deficiency on the metabolism of photoassimilated 14C in sunflower

    International Nuclear Information System (INIS)

    Stanev, V.; Angelov, M.; Popov, G.

    1981-01-01

    In experiments carried out on sunflower the specific changes in the metabolism of photoassimilated 14 C caused by nitrogen deficiency are investigated. The data presented show that nitrogen deficiency in sunflower inhibits the metabolism of photoassimilated 14 C through phosphoglyceric acid and phosphoenolpyruvate and directs it to a great extent through hexo-monophosphates towards the hydrocarbons-sucrose and starch. (authors)

  15. Rapid analysis method for the determination of 14C specific activity in irradiated graphite.

    Directory of Open Access Journals (Sweden)

    Vidmantas Remeikis

    Full Text Available 14C is one of the limiting radionuclides used in the categorization of radioactive graphite waste; this categorization is crucial in selecting the appropriate graphite treatment/disposal method. We propose a rapid analysis method for 14C specific activity determination in small graphite samples in the 1-100 μg range. The method applies an oxidation procedure to the sample, which extracts 14C from the different carbonaceous matrices in a controlled manner. Because this method enables fast online measurement and 14C specific activity evaluation, it can be especially useful for characterizing 14C in irradiated graphite when dismantling graphite moderator and reflector parts, or when sorting radioactive graphite waste from decommissioned nuclear power plants. The proposed rapid method is based on graphite combustion and the subsequent measurement of both CO2 and 14C, using a commercial elemental analyser and the semiconductor detector, respectively. The method was verified using the liquid scintillation counting (LSC technique. The uncertainty of this rapid method is within the acceptable range for radioactive waste characterization purposes. The 14C specific activity determination procedure proposed in this study takes approximately ten minutes, comparing favorably to the more complicated and time consuming LSC method. This method can be potentially used to radiologically characterize radioactive waste or used in biomedical applications when dealing with the specific activity determination of 14C in the sample.

  16. Possibilities of rapid determination of 14C in gaseous discharges from nuclear power facilities

    International Nuclear Information System (INIS)

    Svetlik, Ivo; Tomaskova, Lenka; Pospichal, Jiri; Fejgl, Michal

    2011-01-01

    Two methods of determination of 14 C in stack air accumulated samples from nuclear power plants captured as carbonate are compared and discussed. The usual analytical routine is based on BaCO 3 precipitation and subsequent liquid scintillation (LS) measurement of the resulting suspension in the scintillation mixture. The presented method of 14 C determination applies direct LS counting of accumulated samples containing dissolved carbonates in the scintillation mixture. This method is applicable only to samples with small/negligible amounts of interfering radionuclides (below 10% of 14 C activity). However, during authors' several year experience, significant presence of interfering radionuclides has not been observed (except tritium with E(max) below the low edge of the 14 C measuring window). A disadvantage of the method with direct measurement is a slightly higher limit of determination, about 3 Bq m -3 (TriCarb 3170, measuring time 120 minutes in normal mode). From the point of view of the 14 C discharge balance, the activities of several orders of magnitude Bq do not contribute to the total C budget significantly. The method using direct 14 C measurement facilitates time resolution in the case of rapid changes in 14 C activities in the stack air and reduces costs of the analyses. With use of this method the risk of laboratory contamination is strongly reduced even in the case of samples with elevated 14 C activities. (author)

  17. From source to sink: Unravelling the complex in situ cosmogenic 10Be-14C signature in eroding bedrock surfaces and river sediment from the Bolivian Altiplano

    Science.gov (United States)

    Hippe, Kristina; Lupker, Maarten; Gordijn, Tiemen; Ivy-Ochs, Susan; Kober, Florian; Christl, Marcus; Wacker, Lukas; Hajdas, Irka; Wieler, Rainer

    2017-04-01

    Holocene. Using a simple model of a rapid, one-step denudation rate change, a minimum increase by a factor of 30-40 at about 4-6 ka ago is required to approach the measured in situ 14C-10Be concentrations. This corresponds to the Mid-Holocene shift towards wetter climate in the Eastern Andes as proposed from paleolake deposits [2]. Assuming that fluvial sediments inherit a complex 10Be-14C signal from the source area, the estimated duration of total sediment storage reduces to 1-5 ka and is, thus, much shorter than previously assumed. These time spans correlate well with ages of 2-3 ka obtained for fluvial terraces in the study area by radiocarbon and 10Be depth profile dating. Our data allows tracing the spatial pattern of sediment storage and quantify individual storage durations during source-to-sink sediment transfer through the catchment. We further highlight the potential of the in situ 14C-10Be chronometer to determine the magnitude and timing of changes in surface erosion in the past and, thus, to identify transience in eroding landscapes. [1] Hippe et al., 2012 - Geomorphology 179 - pp. 58-70. [2] Rigsby et al., 2005 - J Quaternary Sci 20 - pp. 671-691.

  18. Bound residues in corn plants treated with 14C-atrazine and bioavailability to rats

    International Nuclear Information System (INIS)

    Khan, S.U.

    1986-01-01

    Corn plants, about 3.5 months old and treated with 14 C-atrazine, were used in an experiment in which the aerial portion of the plants was exhaustively extracted with solvents. The extracted dried material containing bound 14 C-residues was fed to rats. The extracted aerial portion of control corn plants fortified with 14 C-atrazine was also fed to rats. After four days, 88% and 32% of the radioactivity was excreted in the faeces, and 10% and 60% radioactivity was voided in the urine from rats fed plant material containing bound and fortified 14 C-residues, respectively. The data suggest that the bioavailability to rats of bound 14 C-residues in corn material is low. (author)

  19. The release of 14C-chlorsulfuron bound residue by autoclaving method and its identification

    International Nuclear Information System (INIS)

    Guo Jiangfeng; Sun Jinhe; Ye Qingfu

    1999-01-01

    When individual microorganisms were used to release bound pesticide residues, it was usually not take into full account whether the autoclaving method could lead to the release of bound residues. The soil containing bound 14 C-chlorsulfuron residues was treated with an autoclave in this study. The results reveal that the bound 14 C-chlorsulfuron residue can be released from the soil when treated with the autoclave and the release rate can be remarkably enhanced by adding water into the soil when subjected to such treatment. A TLC analysis showed that the released 14 C-residue was one of the degraded products of 14 C-chlorsulfuron. After derivatization and analysis using the GC-MS, the released 14 C-residue was tentatively identified as 2-amino-4-hydroxyl-6-methyl-1,3,5-triazine

  20. Effect of astrocytic energy metabolism depressant on 14C-acetate uptake in intact rat brain.

    Science.gov (United States)

    Hosoi, Rie; Okada, Maki; Hatazawa, Jun; Gee, Antony; Inoue, Osamu

    2004-02-01

    Fluorocitrate, a selective astrocytic toxin, was microinjected into the right striatum of rat brain, and the regional distribution of 14C-acetate was measured using autoradiography. A significant reduction (more than 80%) in 14C-acetate uptake over a 5-minute period was observed in the right striatum, compared with that in the left striatum (saline infused), 4 hours after fluorocitrate (1 nmol/microL) infusion. This effect was transient, and 14C-acetate uptake had almost returned to normal at 24 hours after the fluorocitrate infusion. In contrast, the regional blood flow in the striatum, as determined using 14C-iodoamphetamine, was significantly increased by the fluorocitrate infusion. The present observations indicate that 14C-acetate uptake might be a useful characteristic for examining astrocytic energy metabolism in the intact brain.

  1. Appearance of circulating and tissue 14C-lipids after oral 14C-tripalmitate administration in the late pregnant rat

    International Nuclear Information System (INIS)

    Argiles, J.; Herrera, E.

    1989-01-01

    Studies were performed to determine whether and/or how dietary lipids participate in maternal hypertriglyceridemia during late gestation in the rat. After oral administration of glycerol-tri(1-14C)-palmitate, total radioactivity in plasma increased more rapidly in 20-day pregnant rats than in either 19-day pregnant rats or virgin controls. At the peak of plasma radioactivity, four hours after the tracer was administered, most of the plasma label corresponded to 14C-lipids in triglyceride-rich lipoproteins (d less than 1.006), and when expressed per micromol of triglyceride, values were higher in pregnant than in virgin rats. The difference was less after 24 hours, although at this time the level of 14C-lipids in d less than 1.006 lipoproteins was still higher in 20-day pregnant rats than in virgins. Tissue 14C-lipids, as expressed per gram of fresh weight, were similar in pregnant and virgin rats, but the values in mammary glands were much higher in the former group. Estimated recovery of administered radioactivity four hours after tracer in total white adipose tissue, mammary glands, and plasma lipids was higher in pregnant than in virgin rats. No difference was found between 20-day pregnant and virgin rats either in the label retained in the gastrointestinal tract or in that exhaled as 14C-CO2 during the first four hours following oral administration of 14C-tripalmitate. These findings plus the known maternal hyperphagia, indicate that in the rat at late pregnancy triglyceride intestinal absorption is unchanged or even enhanced and that dietary lipids actively contribute to both maternal hypertriglyceridemia and lipid uptake by the mammary gland

  2. Distribution of photosynthetically fixed 14C in perennial plant species of the northern Mojave Desert

    International Nuclear Information System (INIS)

    Wallace, A.; Cha, J.W.; Romney, E.M.

    1980-01-01

    The distribution of photosynthate among plant parts subsequent to its production is needed to fully understand behavior of vegetation in any ecosystem. The present study, undertaken primarily to obtain information on transport of assimilates into roots of desert vegetation, was conducted in the northern Mojave Desert, where the mean annual rainfall is about 10 cm. Shoots of Ambrosia dumosa (A. Gray) Payne plants were exposed to 14 CO 2 in 1971, and the distribution of 14 C in roots, stems, and leaves was subsequently measured at 1 week, 2 months, and 5 months. Only about 12 percent of the 14 C photosynthate was stored in the root. Much of that stored in stems was available for new leaf growth. Photosynthate was labeled with 14 C for 24 plants representing eight species in 1972. Results showed that after 127 days the mean percentage of 14 C in roots as compared with the estimate of that originally fixed was 11.8; the percentage in stems was 43.8. To check the validity of the 14 C data, root growth of eight perennial desert plants grown in the glasshouse was followed as plants increased in size. The mean percent of the whole plant that was root for eight species was 17.7 percent. The mean proportion of the increase in plant weights that went below ground for the eight species was 19.5 percent. This value is higher than the fraction of 14 C found below ground, and therefore the 14 C technique underestimates the movement of C to roots. Results of an experiment designed to test the value of the 14 C-pulse technique for determining current root growth for some perennial species from the desert indicated that the transition part of roots where root growth continued after exposure to 14 C was highly labeled. Old growth contained less 14 C than new growth

  3. Effects of fertilizers, fungicides and herbicides on the fate of 14C-parathion and 14C-fonofos in soils and crops

    International Nuclear Information System (INIS)

    Lichtenstein, E.P.; Ferris, I.; Liang, T.T.; Koeppe, M.

    1983-01-01

    The fate of 14 C-parathion and 14 C-fonofos in soil is significantly affected by the presence of organic and inorganic fertilizers, fungicides and herbicides, possibly via the effect of soil microflora. Soil microorganisms are responsible for the oxidative as well as the reductive degradation of the insecticide. Using 14 carbon, the authors studied the effects of selected fungicides (benlate, captafol and manzate) herbicides (2,4-D parathion) and fertilizers ((NH 4 ) 6 SO 4 , KNO 3 , urea) on pesticides in Cromberry soils. Results of the study stress the importance of investigating the environmental fate of a particular pesticide in relation to the presence of the agricultural chemicals

  4. Preparation of 2-[α-(2-ethoxyphenoxy)benzyl]-[5-14C]morpholine methanesulfonate ([14C]reboxetine):a new antidepressant agent

    International Nuclear Information System (INIS)

    Angiuli, P.; Fontana, E.; Vicario, G.P.

    1991-01-01

    The labelling with radiocarbon of the new antidepressant agent Reboxetine is described. The preparation has been carried out in a two step procedure using 2-chloro-N-(3-(2-ethoxyphenoxy)-2-hydroxy-3-phenyl)propyl-[1- 14 C]acetamide as starting material. The expected compound was prepared by cyclization of the above halogenoacylamido alcohol to the corresponding morpholone ring followed by reduction to the final [5- 14 C]morpholine derivative 4, 98% radiochemically pure and with specific radioactivity of 988 MBq/mmol. An overall radiochemical yield of 57.5% was achieved. (author)

  5. 14C SIRI samples at CNA: Measurements at 200 kV and 1000 kV

    International Nuclear Information System (INIS)

    Santos Arévalo, Francisco-Javier; Gómez Martínez, Isabel; Agulló García, Lidia

    2015-01-01

    The Sixth International Radiocarbon Intercomparison (SIRI) exercise has taken place during late 2013 and 2014. 13 samples were distributed for AMS (Accelerator Mass Spectrometry) and 5 for radiometric laboratories, including one sample exclusively for radiometric laboratories. Being the first opportunity for our laboratory to participate actively in an intercomparison exercise, we have prepared and measured the samples in the two existing AMS dedicated facilities at the Centro Nacional de Aceleradores (CNA): SARA (Spanish Accelerator for Radionuclide Analysis), a 1 MV multielemental AMS system from HVEE, and Micadas, a 200 kV radiocarbon dating system designed by ETH. Results are presented for the two systems, together with a description of both the sample preparation and measurement procedures.

  6. {sup 14}C SIRI samples at CNA: Measurements at 200 kV and 1000 kV

    Energy Technology Data Exchange (ETDEWEB)

    Santos Arévalo, Francisco-Javier, E-mail: fj.santos@csic.es; Gómez Martínez, Isabel; Agulló García, Lidia

    2015-10-15

    The Sixth International Radiocarbon Intercomparison (SIRI) exercise has taken place during late 2013 and 2014. 13 samples were distributed for AMS (Accelerator Mass Spectrometry) and 5 for radiometric laboratories, including one sample exclusively for radiometric laboratories. Being the first opportunity for our laboratory to participate actively in an intercomparison exercise, we have prepared and measured the samples in the two existing AMS dedicated facilities at the Centro Nacional de Aceleradores (CNA): SARA (Spanish Accelerator for Radionuclide Analysis), a 1 MV multielemental AMS system from HVEE, and Micadas, a 200 kV radiocarbon dating system designed by ETH. Results are presented for the two systems, together with a description of both the sample preparation and measurement procedures.

  7. 14C SIRI samples at CNA: Measurements at 200 kV and 1000 kV

    Science.gov (United States)

    Santos Arévalo, Francisco-Javier; Gómez Martínez, Isabel; Agulló García, Lidia

    2015-10-01

    The Sixth International Radiocarbon Intercomparison (SIRI) exercise has taken place during late 2013 and 2014. 13 samples were distributed for AMS (Accelerator Mass Spectrometry) and 5 for radiometric laboratories, including one sample exclusively for radiometric laboratories. Being the first opportunity for our laboratory to participate actively in an intercomparison exercise, we have prepared and measured the samples in the two existing AMS dedicated facilities at the Centro Nacional de Aceleradores (CNA): SARA (Spanish Accelerator for Radionuclide Analysis), a 1 MV multielemental AMS system from HVEE, and Micadas, a 200 kV radiocarbon dating system designed by ETH. Results are presented for the two systems, together with a description of both the sample preparation and measurement procedures.

  8. Developments towards a fully automated AMS system

    International Nuclear Information System (INIS)

    Steier, P.; Puchegger, S.; Golser, R.; Kutschera, W.; Priller, A.; Rom, W.; Wallner, A.; Wild, E.

    2000-01-01

    The possibilities of computer-assisted and automated accelerator mass spectrometry (AMS) measurements were explored. The goal of these efforts is to develop fully automated procedures for 'routine' measurements at the Vienna Environmental Research Accelerator (VERA), a dedicated 3-MV Pelletron tandem AMS facility. As a new tool for automatic tuning of the ion optics we developed a multi-dimensional optimization algorithm robust to noise, which was applied for 14 C and 10 Be. The actual isotope ratio measurements are performed in a fully automated fashion and do not require the presence of an operator. Incoming data are evaluated online and the results can be accessed via Internet. The system was used for 14 C, 10 Be, 26 Al and 129 I measurements

  9. Proceedings of the first JAEA tandetron AMS utilization workshop

    International Nuclear Information System (INIS)

    Amano, Hikaru; Kabuto, Shoji

    2008-04-01

    Accelerator Mass Spectrometer (AMS) can determine ultra low level long-lived radioactive isotopes in high sensitivity and precision. Tandetron AMS, originally introduced at Mutsu Establishment, the former Japan Atomic Energy Research Institute (JAERI), had been adjusted for the measurement of 14 C and 129 I. The AMS has mainly been used for marine research around the Japan Sea. This AMS has adopted the open door policy for the general users from the spring of 2006. Recently varieties of research activities using this AMS have been in progress by many users. This workshop aimed to not only exchange information on the AMS and its utilization but also continue stable operation of the AMS. First JAEA-AMS-MUTSU Utilization Workshop was held at Mutsu office, JAEA in November 14, 2007. In the workshop 76 participants attended. The topics of the conference concerned recent utilization status of AMS, data processing from the AMS, 14 C measurement and its application, 129 I measurement and its application, and so on. This proceeding includes 21 papers at the workshop. This publication is the collection of the paper presented at the title meeting. The 21 of the presented papers are indexed individually. (J.P.N.)

  10. Synthesis of [14C]ABT-418, a cholinergic channel activator labeled at two sites on the isoxazole ring

    International Nuclear Information System (INIS)

    Surber, B.W.; Thomas, S.B.; Elliott, R.L.; Kopecka, Hana

    1996-01-01

    [ 14 C]ABT-418, (S)-3-[ 14 C]methyl-5-[N-methyl-2-pyrrolidinyl] [4- 14 C]isoxazole hydrochloride, was labeled in two positions at maximum specific activity. Starting with 100 mCi of sodium [2- 14 C]acetate, 14.6 mCi at 105 mCi/mmol was obtained in 8 steps including the formation of [1,3- 14 C]acetone in the pyrolysis of barium [2- 14 C]acetate. The key step was the formation of the dianion of [1,3- 14 C]acetone oxime and its condensation with L-proline methyl ester. (author)

  11. Absorption, distribution, metabolism and excretion of 14C-chlorphenesin carbamate in rats

    International Nuclear Information System (INIS)

    Nozu, Takashi; Aoyagi, Tadao; Setoyama, Kageyoshi; Suwa, Toshio; Tanaka, Ichiro

    1977-01-01

    Absorption, distribution, metabolism and excretion of chlorphenesin carbamate (CPC), a central acting muscle relaxant, were investigated in rats by use of 14 C-labeled CPC. After oral administration, 14 C-CPC was well absorbed from gastrointestinal tract and about 90% of the given radioactivity was excreted in urine and 5% in feces during 5 days. Approximately 36% was recovered in bile during 8 hr after oral administration. The highest blood level of 14 C was observed at 3-8 hr after oral administration and decreased slowly. The radioactivity was distributed widely in almost all tissues. The highest concentration of 14 C was observed in the liver and the higher was detected in the brain and spinal cord, suggesting a pharmacological effect of CPC. In pregnant rats given 14 C-CPC orally, the radioactivity in the fetuses was below 0.8% of the dose at 1-24 hr. The major metabolites in 48 hr urine was identified as CPC-glucuronide and the acidic metabolites, p-chlorophenoxylactic acid, p-chlorophenoxyacetic acid and p-chlorophenol, were also detected. After intravenous injection of the 14 C-labeled acidic metabolites, the radioactivity was not detected in the central nervous system and excreted rapidly. In the case of repeated administration of CPC and 14 C-CPC for 21 days, the radioactivity did not accumulated in any tissue of rats. (auth.)

  12. Turnover of 14C-glucose in soils and its relationship with soil characters

    International Nuclear Information System (INIS)

    Ni Jinzhi; Xu Jianmin; Xie Zhengmiao; Ye Qingfu

    2001-01-01

    The turnover of 14 C-glucose added in 13 soils was studied. The turnover rate of 14 C-glucose can be divided into three phases: 0 - 3d, 3 - 28d and 28 - 294d. The range of the turnover rate and half -life of 14 C-glucose were 1.3 x 10 -1 - 2.5 x 10 -1 d -1 and 3 - 5d, 0.7x 10 -2 - 1.2 x 10 -2 d -1 and 58 - 97d, 0.5 x 10 -3 - 1.4 x 10 -3 d -1 and 491 - 1504d, respectively. Correlation analysis showed that from 0 to 3 days the turnover rate of 14 C-glucose had significant positive correlation with soil qCO 2 , from 3 to 28 days, the turnover rate of 14 C-glucose had no significant correlation with soil physico-chemical and biological properties. The turnover rate of 14 C-glucose had significant or highly significant negative correlation with soil total organic carbon, total nitrogen, CEC and significant positive correlation with soil sand content during the period from 28 to 294 days. Turnover of 14 C-glucose during the third period has close correlation with soil properties

  13. A study on alfalfa-dodder relationships by 14C-sucrose incorporation in their tissues

    International Nuclear Information System (INIS)

    Tsenova, M.

    1975-01-01

    Plant-parasite relationships between lesser-dodder (Cuscuta epithymum) and alfalfa (Medicago sativa) are investigated. 14 C-sucrose was incorporated via the cut stems of host and parasite into their tissues and the content of the free sugars, keto acids and free amino acids are determined. 14 C-sucrose was introduced also in lesser-dodder previously taken from the host-plant and immersed directly into radioactive sucrose. It is shown that the parasite intensively absorbs sucrose from the host-plant tissues using it as a source of energy and as a substrat for different synthetic processes. In the case when the parasite was previously taken away from the host-plant 14 C-sucrose taken up directly from the solution was used for the synthesis of various compounds (carbohydrates, amino- and keto acids). The suggestion was made that the respective enzyme systems are present in dodder tissues. The 14 C-glucose and 14 C-fructose content is an evidence for high invertase hydrolytic activity. The presence of 14 C-keto acids shows that the 14 C-sucrose incorporated in lesser-dodder tissues without the mediation of the host-plant was used as a respiratory substrate by the degradation following Krebs cycle. (author)

  14. The distribution of Δ{sup 14}C in Korea from 2010 to 2013

    Energy Technology Data Exchange (ETDEWEB)

    Park, J.H., E-mail: junghun@kigam.re.kr [Korea Institute of Geoscience and Mineral Resources (KIGAM), 124 Gwahang-no. Yuseong, Daejeon 305-350 (Korea, Republic of); Hong, W. [Korea Institute of Geoscience and Mineral Resources (KIGAM), 124 Gwahang-no. Yuseong, Daejeon 305-350 (Korea, Republic of); Xu, X. [Keck/CCAMS Lab, 3327 Croul Hall, University of California, Irvine, CA 92697 (United States); Park, G.; Sung, K.S.; Sung, Kilho; Lee, Jong-geol; Nakanishi, T.; Park, Hyo-Seok [Korea Institute of Geoscience and Mineral Resources (KIGAM), 124 Gwahang-no. Yuseong, Daejeon 305-350 (Korea, Republic of)

    2015-10-15

    Δ{sup 14}C values of leaves of a deciduous tree record to those of atmospheric CO{sub 2} within error and were used to map out Δ{sup 14}C distribution in Korea. We collected ginkgo (Ginkgo biloba Linnaeus, a deciduous tree) leaf samples in mid-June to early July from 2009 to 2013 in Korea to obtain the regional distribution of Δ{sup 14}C. Commonly CO{sub 2} emitted from fossil fuel consumption dilutes atmospheric {sup 14}C, while operations and accidents at nuclear power plants can increase it. The distribution maps of Δ{sup 14}C from 2010 to 2013 in Korea shows that Δ{sup 14}C values in the northwestern and southeastern parts of Korea are lower than those of the other parts of Korea, which is consistent with the population and industry patterns. Decrease rates of annually averaged Δ{sup 14}C values in Korea over the study period are larger than those of Pt. Barrow, Alaska, USA (71.3°N, 156.5°W), so the difference between them and those of Pt. Barrow, Alaska, USA became larger annually. This may be due to the increase in fossil fuel consumption in Korea and China. The decrease rate between 2010 and 2011 was smaller than in other years. This could be the effect of the Fukushima power plant accident which occurred in March 11, 2011, but further study is needed to clarify it.

  15. Closed tubes preparation of graphite for high-precision AMS radiocarbon analysis

    Science.gov (United States)

    Hajdas, I.; Michczynska, D.; Bonani, G.; Maurer, M.; Wacker, L.

    2009-04-01

    Radiocarbon dating is an established tool applied in Geochronology. Technical developments of Accelerator Mass Spectrometry AMS, which allow measurements of samples containing less than 1 mg of carbon, opened opportunities for new applications. Moreover, high resolution records of the past changes require high-resolution chronologies i.e. sampling for 14C dating. In result, the field of applications is rapidly expanding and number of radiocarbon analysis is growing rapidly. Nowadays dedicated 14C AMS machines have great capacity for analysis but in order to keep up with the demand for analysis and provide the results as fast as possible a very efficient way of sample preparation is required. Sample preparation for 14C AMS analysis consists of two steps: separation of relevant carbon from the sample material (removing contamination) and preparation of graphite for AMS analysis. The last step usually involves reaction of CO2 with H2, in the presence of metal catalyst (Fe or Co) of specific mesh size heated to 550-625°C, as originally suggested by Vogel et al. (1984). Various graphitization systems have been built in order to fulfil the requirement of sample quality needed for high-precision radiocarbon data. In the early 90ties another method has been proposed (Vogel 1992) and applied by few laboratories mainly for environmental or biomedical samples. This method uses TiH2 as a source of H2 and can be easily and flexibly applied to produce graphite. Sample of CO2 is frozen in to the tube containing pre-conditioned Zn/TiH2 and Fe catalyst. Torch sealed tubes are then placed in the stepwise heated oven at 500/550°C and left to react for several hours. The greatest problem is the lack of control of the reaction completeness and considerable fractionation. However, recently reported results (Xu et al. 2007) suggest that high precision dating using graphite produced in closed tubes might be possible. We will present results of radiocarbon dating of the set of standards

  16. Tracer experiment administering L-phenylalanine-U-14C and L-tyrosine-U-14C to the tissue slices of bamboo shoots

    International Nuclear Information System (INIS)

    Kozukue, E.; Mizuno, S.

    1987-01-01

    Uniformly 14 C-labeled L-phenylalanine and L-tyrosine were administered to tissue slices of both top and base sections of bamboo shoots. Alcohol soluble substances were extracted and then separated into organic acid, sugar and amino acid fractions by ion exchange chromatography. The homogentisic acid fraction among the organic acids was collected by high-performance liquid chromatography (HPLC) and its radioactivity was measured, while the alcohol insoluble residue was used for the analysis of lignin aldehyde by the method of alkaline nitrobenzene oxidation. 1. The two labeled amino acids were steadily incorporated into the tissues during incubation and rapidly converted to organic acid, sugar and alcohol insoluble residue, especially the latter. 2. On determining the amount of phenylalanine converted to tyrosine, it was found that this was extremely small. 3. The incorporation of phenylalanine-U- 14 C into alcohol insoluble residue was higher than that of tyrosine in both sections. 4. Although the conversion into lignin aldehyde from phenylalanine-U- 14 C was higher than that from tyrosine-U- 14 C, it was found that tyrosine incorporated into the shoots was converted to a remarkable extent for formation of lignin aldehyde. 5. The incorporation of phenylalanine and tyrosine into homogentisic acid was very low. From these results, we assume that the conversion of phenylalanine to tyrosine or of tyrosine to homogentisic acid is very small, and that a part of the high amount of tyrosine in the shoots may be used for formation of lignin

  17. Is Comparability of 14C Dates an Issue?: A Status Report on the Fourth International Radiocarbon Intercomparison

    NARCIS (Netherlands)

    Bryant, C.; Carmi, I.; Cook, G.T.; Gulliksen, S.; Harkness, D.D.; Heinemeier, J.; McGee, E.; Naysmith, P.; Possnert, G.; Scott, E.M.; Plicht, J. van der; Strydonck, M. van

    2001-01-01

    For more than 15 years, the radiocarbon community has participated in a series of laboratory intercomparisons in response to the issue of comparability of measurements as perceived within the wider user communities (Scott et al. 1990; Rozanski et al. 1992; Guiliksen and Scott 1995; Scott et al.

  18. Preparation of 14C-labelled urea for diagnosis of helicobacter pylori infection

    International Nuclear Information System (INIS)

    Jiang Bingsheng

    2001-01-01

    The preparation of 14 C-urea from [ 14 C]-barium carbonate is reported. The results show that chemical yield can reach 80% (average of 6 runs); melt point is 132 - 136 degree C; purity is 99.65% - 99.85%. After being analyzed by IR, UV, NMR, MS, and elemental analysis, the 14 C-urea has the same molecular structure as that of standard urea. Animal trial indicates that clinical use is safe. Good stability is shown by stability testing under different luminous flux, temperature and relative humidity

  19. Synthesis of {sup 14}C-labeled levamisole and {sup 13}C-labeled tetramisole

    Energy Technology Data Exchange (ETDEWEB)

    Feil, V.J. [US Department of Agriculture, Agricultural Research Service, Biosciences Research Lab., Fargo, ND (United States)

    1996-12-01

    The syntheses of {sup 14}C-ring labeled levamisole ([-]-2,3,5,6-tetrahydro-6-phenyl [{sup 14}C]-UL imidazo[2,1-b]thiazole) from acetophenone-ring-UL-{sup 14}C in 5 steps plus resolution with a 7.5% overall yield, and {sup 13}C{sub 6}-ring labeled tetramisole ([{+-}]-2,3,5,6-tetrahydro-6-phenyl [{sup 13}C{sub 6}]imidazo[2,1-b]thiazole) from benzene-{sup 13}C{sub 6} in 6 steps with a 9.0% overall yield are described. (author).

  20. Confirmation of eradication of Helicobacter pylori infection by 14C-urea breath test

    International Nuclear Information System (INIS)

    Pathak, C.M.; Bhasin, D.K.; Sharma, B.C.; Roy, P.; Vaiphei, K.

    1998-01-01

    Helicobacter pylori (H. pylori) is a potent urease producer, a characteristic that has been exploited in the development of the 14 C-urea breath test (UBT). 14 C-UBT is being used as a highly reliable test for the diagnosis of H. pylori infection. There is paucity of reports on the utility of this test to confirm the H. pylori eradication after its treatment. The study was conducted to determine the utility of 14 C-UBT in confirming the eradication of H. pylori

  1. Facile method of preparation and purification of 14C-labelled 2,4-dichlorophenoxyacetic acid

    International Nuclear Information System (INIS)

    Vaghani, D.D.; Shownkeen, G.C.; Prabhanjan Kumar; Asokan, K.P.

    1992-01-01

    Sodium bromo acetate [1- 14 C] was prepared from sodium acetate [1- 14 C] by bromination followed by neutralisation with sodium hydroxide. It was then condensed with 2,4-dichloro phenol in aqueous sodium hydroxide. 2,4-dichloro phenoxy[1- 14 C] acetic acid was isolated from the reaction mixture by passing carbon dioxide gas, extraction with ether and acidification of the aqueous layer. The product was further purified by treatment with sodium bicarbonate and silica gel column chromatography. (author). 3 refs

  2. Natural Abundance 14C Content of Dibutyl Phthalate (DBP from Three Marine Algae

    Directory of Open Access Journals (Sweden)

    Kazuyo Ukai

    2006-11-01

    Full Text Available Abstract: Analysis of the natural abundance 14C content of dibutyl phthalate (DBP from two edible brown algae, Undaria pinnatifida and Laminaria japonica, and a green alga, Ulva sp., revealed that the DBP was naturally produced. The natural abundance 14C content of di-(2-ethylhexyl phthalate (DEHP obtained from the same algae was about 50-80% of the standard sample and the 14C content of the petrochemical (industrial products of DBP and DEHP were below the detection limit.

  3. Mineralisation of14C-labelled polystyrene plastics by Penicillium variabile after ozonation pre-treatment.

    Science.gov (United States)

    Tian, Lili; Kolvenbach, Boris; Corvini, Nora; Wang, Songfeng; Tavanaie, Nasrin; Wang, Lianhong; Ma, Yini; Scheu, Stefan; Corvini, Philippe François-Xavier; Ji, Rong

    2017-09-25

    Large amounts of polystyrene (PS), one of the most widely used plastics in the world, end up in the environment through industrial discharge and littering, becoming one of the major components of plastic debris. Such plastics, especially the small-sized microplastics and nanoplastics, have received increasing concerns in terms of their potential environmental risks. Feasible approaches for the degradation of PS in waste materials and in the environment are highly desirable. Physicochemical pretreatments of PS may be applied to enhance biological degradation. In the present study, we synthesized 14 C-labelled PS polymers, either uniformly labelled on the ring ([U-ring- 14 C]-PS) or labelled at the β-carbon position of the alkyl chain ([β- 14 C]-PS), and investigated the mineralisation of the 14 C-PS polymers by the fungus Penicillium variabile CCF3219 as well as the effect of ozonation as a physico-chemical pre-treatment on the mineralisation by the fungi. Biodegradation of the 14 C-PS polymers was studied in liquid medium (pH 7.5, without additional carbon substrate) with P. variabile for 16 weeks. During the incubation time, 14 CO 2 was captured to calculate the mineralisation of 14 C-PS and the remaining polymers were analysed by means of scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectrometry and gel-permeation chromatography (GPC). The results showed that the fungi mineralised both labelled polymers, and that the [U-ring- 14 C]-PS with a lower molecular weight led to a higher mineralisation rate. Ozonation pre-treatment strongly enhanced mineralisation of [β- 14 C]-PS. SEM analysis showed that the surface of the ozonated [β- 14 C]-PS became uneven and rough after the incubation, indicating an attack on the polymer by P. variabile. FT-IR analysis showed that ozonation generated carbonyl groups on the [β- 14 C]-PS and the amount of the carbonyl groups decreased after incubation of the [β- 14 C]-PS with P. variabile. GPC analysis

  4. Free and proteic aminoacids from acetate 14C metabolism in detached leaves of coffee plant

    International Nuclear Information System (INIS)

    Brasil, O.G.; Crocomo, O.J.

    1981-01-01

    The acetate 14 C was studied as the forerunner of proteic and free aminoacids in detached leaves of coffee (coffea arabica L.cv. Mundo Novo). The detached leaves were incubated with acetate -1- 14 C and -2- 14 C during several times (15, 30, 45, 60, 90, 120, 150 and 180 minutes), out of luminosity. The ethanol 80% soluble fraction gave origin to free aminoacid after ion - exchange chromatography. The insoluble fraction through acid hydrolisis furnished proteic aminoacids. The data showed that the acetate molecules contributed for the aminoacids molecules structure, methylic carbon being more incorporated than the carboxylic carbon. (Author) [pt

  5. Synthesis of C-9-14C-1,8-dihydroxy-3-carboxyanthraquinone

    International Nuclear Information System (INIS)

    De Witte, P.; Lemli, J.

    1988-01-01

    The synthesis of C-9- 14 C-rhein is reported using 14 CO 2 as a 14 C-source. After preparing 14 C-1, 8-dimethoxy-3-methylanthraquinone by a condensation reaction, the product is demethylated and the 3-methyl group converted to the corresponding 3-carboxy group. The radio-active yield of the total synthesis, starting with 1 Ci 14 CO 2 is 6,9% (6, 9 mCi); 352 mg 14 rhein is produced with a specific activity of 55,7 mCi/mmol. (author)

  6. [{sup 14}C]Benzyl acetate is a potential radiotracer for the measurement of glial metabolism in the rat brain

    Energy Technology Data Exchange (ETDEWEB)

    Momosaki, Sotaro [Division of Health Sciences, Graduate School of Medicine, Osaka University, Osaka 565-0871 (Japan)], E-mail: momosaki@sahs.med.osaka-u.ac.jp; Hosoi, Rie; Sanuki, Tomoya [Division of Health Sciences, Graduate School of Medicine, Osaka University, Osaka 565-0871 (Japan); Todoroki, Kenichiro; Yamaguchi, Masatoshi [Faculty of Pharmaceutical Sciences, Fukuoka University, Nanakuma, Johnan-ku, Fukuoka 814-0180 (Japan); Gee, Antony [GlaxoSmithkline, Clinical Research Unit, ACCI, CB2 2GC Cambridge (United Kingdom); Department of Chemistry, Imperial College of London, SW7 2AZ London (United Kingdom); Inoue, Osamu [Division of Health Sciences, Graduate School of Medicine, Osaka University, Osaka 565-0871 (Japan)

    2007-11-15

    In order to develop a suitable radiotracer for the measurement of glial metabolism, we synthesized four different types of ester derivatives of [{sup 14}C]acetate, namely, [{sup 14}C]phenyl acetate, [{sup 14}C]para-nitrophenyl acetate, [{sup 14}C]2,4-dinitrophenyl acetate and [{sup 14}C]benzyl acetate ([{sup 14}C]BA), and evaluated their potencies in rats. Among the derivatives, the highest brain uptake at 30 s postinjection was observed for [{sup 14}C]BA, which was more than 23 times higher than that of [{sup 14}C]acetate itself. A long-term retention of [{sup 14}C]BA radioactivity in the brain was observed, whereas rapid clearance of radioactivity was seen in the heart. [{sup 14}C]BA was rapidly hydrolyzed in the intact rat brain, and less than 5% of radiolabeled parent was observed 1 min after the injection. Radiochemical analysis using thin-layer chromatography revealed that [{sup 14}C]BA was rapidly converted to [{sup 14}C]glutamine and [{sup 14}C]glutamate in the cortex within 10 min after injection. Furthermore, the uptake of [{sup 14}C]BA was significantly decreased following microinjection of fluorocitrate, a selective glial toxin. These results strongly suggest that [{sup 14}C]BA may be a useful radiotracer for the measurement of glial metabolism in the intact rat brain.

  7. Reservoir effects in radiocarbon dating

    International Nuclear Information System (INIS)

    Head, M.J.

    1997-01-01

    Full text: The radiocarbon dating technique depends essentially on the assumption that atmospheric carbon dioxide containing the cosmogenic radioisotope 14 C enters into a state of equilibrium with all living material (plants and animals) as part of the terrestrial carbon cycle. Terrestrial reservoir effects occur when the atmospheric 14 C signal is diluted by local effects where systems depleted in 14 C mix with systems that are in equilibrium with the atmosphere. Naturally, this can occur with plant material growing close to an active volcano adding very old CO 2 to the atmosphere (the original 14 C has completely decayed). It can also occur in highly industrialised areas where fossil fuel derived CO 2 dilutes the atmospheric signal. A terrestrial reservoir effect can occur in the case of fresh water shells living in rivers or lakes where there is an input of ground water from springs or a raising of the water table. Soluble bicarbonate derived from the dissolution of very old limestone produces a 14 C dilution effect. Land snail shells and stream carbonate depositions (tufas and travertines) can be affected by a similar mechanism. Alternatively, in specific cases, these reservoir effects may not occur. This means that general interpretations assuming quantitative values for these terrestrial effects are not possible. Each microenvironment associated with samples being analysed needs to be evaluated independently. Similarly, the marine environment produces reservoir effects. With respect to marine shells and corals, the water depth at which carbonate growth occurs can significantly affect quantitative 14 C dilution, especially in areas where very old water is uplifted, mixing with top layers of water that undergo significant exchange with atmospheric CO 2 . Hence, generalisations with respect to the marine reservoir effect also pose problems. These can be exacerbated by the mixing of sea water with either terrestrial water in estuaries, or ground water where

  8. SUERC AMS ion detection

    Science.gov (United States)

    Maden, C.; Anastasi, P. A. F.; Dougans, A.; Freeman, S. P. H. T.; Kitchen, R.; Klody, G.; Schnabel, C.; Sundquist, M.; Vanner, K.; Xu, S.

    2007-06-01

    In a short time Be, C, Al, Cl, Ca and I accelerator mass spectrometry (AMS) have been established on the National Electrostatics Corporation (NEC) 5 MV pelletron system at the Scottish Universities Environmental Research Centre (SUERC). While summarising the present performance of the system, this report will focus on the details of ion detection, which sample materials are used and the analytical procedures employed for each individual species during routine analysis. All rare isotope detection is with a single flexible detector and ion event analysis system, but switching of analysed species typically requires a detector reconfiguration. Configurations for routine 10Be, 14C, 26Al, 36Cl, 41Ca and 129I detection have been established and will be presented here. Notably, there has proven to be sufficient suppression of the isobaric interferences of 36Cl and 41Ca in the 5+ charge state using an argon gas stripper at a terminal voltage of 5.0 MV to allow for routine analysis of these isotopes.

  9. Earliest Human Presence in North America Dated to the Last Glacial Maximum: New Radiocarbon Dates from Bluefish Caves, Canada.

    Science.gov (United States)

    Bourgeon, Lauriane; Burke, Ariane; Higham, Thomas

    2017-01-01

    The timing of the first entry of humans into North America is still hotly debated within the scientific community. Excavations conducted at Bluefish Caves (Yukon Territory) from 1977 to 1987 yielded a series of radiocarbon dates that led archaeologists to propose that the initial dispersal of human groups into Eastern Beringia (Alaska and the Yukon Territory) occurred during the Last Glacial Maximum (LGM). This hypothesis proved highly controversial in the absence of other sites of similar age and concerns about the stratigraphy and anthropogenic signature of the bone assemblages that yielded the dates. The weight of the available archaeological evidence suggests that the first peopling of North America occurred ca. 14,000 cal BP (calibrated years Before Present), i.e., well after the LGM. Here, we report new AMS radiocarbon dates obtained on cut-marked bone samples identified during a comprehensive taphonomic analysis of the Bluefish Caves fauna. Our results demonstrate that humans occupied the site as early as 24,000 cal BP (19,650 ± 130 14C BP). In addition to proving that Bluefish Caves is the oldest known archaeological site in North America, the results offer archaeological support for the "Beringian standstill hypothesis", which proposes that a genetically isolated human population persisted in Beringia during the LGM and dispersed from there to North and South America during the post-LGM period.

  10. Microscale radiocarbon dating of paintings

    Energy Technology Data Exchange (ETDEWEB)

    Hendriks, Laura; Hajdas, Irka; McIntyre, Cameron [ETH Zurich, Ion Beam Physics, Zurich (Switzerland); Kueffner, Markus; Ferreira, Ester S.B. [SIK-ISEA, Zurich, Zurich (Switzerland); Scherrer, Nadim C. [Bern University of Applied Sciences, HKB, Bern (Switzerland)

    2016-03-15

    In this paper, radiocarbon dating of paintings using minimal sample sizes has been investigated, in an effort to address the problem of limited access to sample material in paintings. {sup 14}C analyses were conducted on signed and dated paintings from two Swiss artists of the twentieth century. The selected paintings dated from the 1930s and 1960s, provided the opportunity to evaluate the dating accuracy on paintings realized before and after 1950 AD when the {sup 14}C bomb peak was created, as a result of the nuclear tests conducted in the 1950/1960s. The work focused on the one hand on minimizing the size of the canvas sample required for accelerator mass spectrometer radiocarbon measurement on the gas ion source of the MICADAS and, on the other hand, on testing the possibility of dating the