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High Precision 14C Analysis in Small Seawater Samples

Published online by Cambridge University Press:  19 August 2019

Núria Casacuberta*
Affiliation:
Laboratory of Ion Beam Physics, ETH Zürich, Otto-Stern-Weg 5, 8093 Zürich, Switzerland
Maxi Castrillejo
Affiliation:
Laboratory of Ion Beam Physics, ETH Zürich, Otto-Stern-Weg 5, 8093 Zürich, Switzerland
Anne-Marie Wefing
Affiliation:
Laboratory of Ion Beam Physics, ETH Zürich, Otto-Stern-Weg 5, 8093 Zürich, Switzerland Institute of Biogeochemistry and Pollutant Dynamics, Environmental Physics, Universitätstrasse 16, 8092 Zürich, Switzerland
Silvia Bollhalder
Affiliation:
Laboratory of Ion Beam Physics, ETH Zürich, Otto-Stern-Weg 5, 8093 Zürich, Switzerland
Lukas Wacker
Affiliation:
Laboratory of Ion Beam Physics, ETH Zürich, Otto-Stern-Weg 5, 8093 Zürich, Switzerland
*
*Corresponding author. Email: ncasacuberta@phys.ethz.ch.

Abstract

A new method to extract CO2 in seawater samples for the determination of F14C has been developed in the Laboratory of Ion Beam Physics at ETH Zurich. The setup consists of an automated sampler designed to extract dissolved inorganic carbon (DIC) from 7 samples in a row, by flushing the seawater with He gas to extract CO2. The fully automated method is controlled via a LabVIEW program that runs through all consecutive steps: catalyst preconditioning, CO2 extraction, CO2 trapping, thermal CO2 release from the trap into the reactor and finally the graphitization reaction which is performed simultaneously in the 7 reactors. The method was optimized by introducing a Cu-Ag furnace that was placed between the water and zeolite traps, which resulted in a better and faster graphitization performance (<2 hr) compared to previously used techniques. The method showed to be reproducible with an unprecedented precision of 1.7‰ even though consuming only 50–60 mL of seawater. The high throughput of 21 samples per day allows for coverage of future oceanographic transects with high spatial resolution, thus fostering the use of radiocarbon (14C) as water mass tracer.

Type
Research Article
Copyright
© 2019 by the Arizona Board of Regents on behalf of the University of Arizona 

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References

REFERENCES

Broecker, WS. 1991. The great ocean conveyor. Oceanography 4(2):7989. doi: 10.5670/oceanog.1991.07.CrossRefGoogle Scholar
Broecker, WS, Sutherland, S, Smethie, W, Peng, TH, Ostlund, G. 1995. Oceanic radiocarbon: Separation of the natural and bomb components. Global Biogeochemical Cycles 9(2): 263288. doi: 10.1029/95GB00208.CrossRefGoogle Scholar
Choe, K, Song, S, Hoon Lee, J, Mi Song, Y, Kang, J, Yun, M, Chan Kim, J. 2013. A study on trapping CO2 using molecular sieve for 14C AMS sample preparation. Radiocarbon 55(2–3): 421425. doi: 10.2458/azu_js_rc.55.16311.CrossRefGoogle Scholar
Gao, P, Xu, X, Zhou, L, Pack, MA, Griffin, S, Santos, GM, Southon, JR, Liu, K. 2014. Rapid sample preparation of dissolved inorganic carbon in natural waters using a headspace-extraction approach for radiocarbon analysis by accelerator mass spectrometry. Limnology and Oceanography: Methods 12(4):174190. doi: 10.4319/lom.2014.12.174.Google Scholar
Gospodinova, K, McNichol, AP, Gagnon, A, Shah Walter, SR. 2016. Rapid extraction of dissolved inorganic carbon from seawater and groundwater samples for radiocarbon dating. Limnology and Oceanography: Methods 14(1):2430. doi: 10.1002/lom3.10066.Google Scholar
Hinger, EN, Santos, GM, Druffel, ERM, Griffin, S. 2010. Carbon isotopes measurements of surface seawater from a time-series site off Southern California. Radiocarbon 52(1):6989. doi: 10.1017/S0033822200045045.CrossRefGoogle Scholar
Jones, GA, Gagnon, AR, von Reden, KF, McNichol, AP, Schneider, RJ. 1994. High-precision AMS radiocarbon measurements of central Arctic Ocean sea waters. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 92(1):426430. doi: 10.1016/0168-583X(94)96048-8.CrossRefGoogle Scholar
Key, RM. 2001. Radiocarbon. In: Steele, JH, editors. Encyclopedia of Ocean Sciences: Oxford, Academic Press. p. 23382353. doi: 10.1006/rwos.2001.016.CrossRefGoogle Scholar
Key, RM, Quay, PD, Schlosser, P, McNichol, AP, von Reden, KF, Schneider, RJ, Elder, KL, Stuiver, M, Östlund, HG. 2002. WOCE Radiocarbon IV: Pacific Ocean results; P10, P13N, P14C, P18, P19 & S4P. Radiocarbon 44(1):239392. doi: 10.1017/S0033822200064845.CrossRefGoogle Scholar
Linick, TW, Damon, PE, Donahue, DJ, Jull, AJT. 1989. Accelerator mass spectrometry: The new revolution in radiocarbon dating. Quaternary International 1(C):16. doi: 10.1016/1040–6182(89)90004-9.CrossRefGoogle Scholar
Matsumoto, K. 2007. Radiocarbon-based circulation age of the world oceans. Journal of Geophysical Research: Oceans 112(C9):17. doi: 10.1029/2007JC004095.CrossRefGoogle Scholar
McNichol, AP, Jones, GA, Hutton, DL, Gagnon, AR, Key, RM. 1994. The rapid preparation of seawater CO2 for radiocarbon analysis at the national ocean sciences AMS facilities. Radiocarbon 36(2): 237246. doi: 10.1017/S0033822200040522.CrossRefGoogle Scholar
McNichol, AP, Quay, PD, Gagnon, A, Burton, JR. 2010. Collection and measurement of carbon isotopes in seawater DIC. In: Hood, EM, Sabine, CL, Sloyan, BM, editors. The GO-SHIP repeat hydrography manual: a collection of expert reports and guidelines. Version 1. 12 p. (IOCCP Report Number 14; ICPO Publication Series Number 134). http://www.go-ship.org/HydroMan.html.Google Scholar
Molnár, M, Hajdas, I, Janovics, R, Rinyu, L, Synal, HA, Veres, M, Wacker, L. 2013. C-14 analysis of groundwater down to the millilitre level. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 294:573576. doi: 10.1016/j.nimb.2012.03.038.CrossRefGoogle Scholar
Östlund, HG, Stuiver, M. 1980. GEOSECS Pacific radiocarbon. Radiocarbon 22(1):2553. doi: 10.1017/S0033822200004707.CrossRefGoogle Scholar
Povinec, PP, Oregioni, B, Jull, AJT, Kieser, WE, Zhao, XL. 2000. AMS measurements of 14C and 129I in seawater around radioactive waste dump sites. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 172(1–4):672678. doi: 10.1016/S0168-583X(00)00106-3.CrossRefGoogle Scholar
Salehpour, M, Håkansson, K, Possnert, G, Wacker, L, Synal, HA. 2016. Performance report for the low energy compact radiocarbon accelerator mass spectrometer at Uppsala University. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 371:360364. doi: 10.1016/j.nimb.2015.10.034.CrossRefGoogle Scholar
Schulze-König, T, Seiler, M, Suter, M, Wacker, L, Synal, HA. 2011. The dissociation of 13CH and 12CH2 molecules in He and N2 at beam energies of 80–250keV and possible implications for radiocarbon mass spectrometry. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 269(1): 3439. doi: 10.1016/j.nimb.2010.09.015.CrossRefGoogle Scholar
Stuiver, M. 1980. 14C distribution in the Atlantic Ocean. Journal of Geophysical Research: Oceans 85(C5): 27112718. doi: 10.1029/JC085iC05p02711.CrossRefGoogle Scholar
Stuiver, M, Östlund, HG. 1980. GEOSECS Atlantic Radiocarbon. Radiocarbon 22(1):124. doi: 10.1017/S0033822200004690.CrossRefGoogle Scholar
Synal, HA, Stocker, M, Suter, M. 2007. MICADAS: A new compact radiocarbon AMS system. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 259(1):713. doi: 10.1016/j.nimb.2007.01.138.CrossRefGoogle Scholar
Wacker, L, Fülöp, RH, Hajdas, I, Molnár, M, Rethemeyer, J. 2013. A novel approach to process carbonate samples for radiocarbon measurements with helium carrier gas. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 294: 214217. doi: 10.1016/j.nimb.2012.08.030.CrossRefGoogle Scholar
Wacker, L, Němec, M, Bourquin, J. 2010. A revolutionary graphitisation system: fully automated, compact and simple. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 268(7–8):931934. doi: 10.1016/j.nimb.2009.10.067.CrossRefGoogle Scholar