Skip to main content

Optimization of the Amount of Zinc in the Graphitization Reaction for Radiocarbon AMS Measurements at LAC-UFF

  • Kita D Macario (a1), Fabiana M Oliveira (a1), Vinicius N Moreira (a1), Eduardo Q Alves (a1) (a2), Carla Carvalho (a1) (a3), Renata M Jou (a1), Maria Isabela Oliveira (a1), Bruna B Pereira (a1), Izabela Hammerschlag (a1), Bruna Netto (a1), Amanda P Seixas (a1), João Vitor P Malafaia (a1), Lara Moreira (a1), Luana Cunha (a1), Ayrton Assumpção (a1), Pedro Mallet (a1), Loise Lima (a1), Fabio Lopes (a1) (a4), Maikel Diaz (a1) (a5), Ingrid S Chanca (a1) and Paulo R S Gomes (a1)...

The Radiocarbon Laboratory of the Universidade Federal Fluminense, in Brazil, has been successfully applying the zinc reduction method for graphitization of carbon samples since the development of its early protocols in 2009. Successive methodological research aiming to improve and, ultimately, optimize the precision and accuracy of our results indicates that graphitization temperatures as low as 460°C promote erratic 13C isotopic fractionation, but an approximately constant fractionation of about –5‰ is achieved at 520°C. In this work, we present isotope ratio mass spectrometry (IRMS) δ13C results for 14C reference materials graphitized at 550°C with variable amounts of zinc. Based on the results obtained from the addition of 20, 35, and 50 mg of zinc, we conclude that a slightly lower variation in 13C isotope fractionation during graphitization is obtained with less zinc. Moreover, the average isotopic fractionation is not altered by increasing the graphitization temperature from 520°C to 550°C.

Corresponding author
*Corresponding author. Email:
Hide All

Selected Papers from the 2015 Radiocarbon Conference, Dakar, Senegal, 16–20 November 2015

Hide All
Anjos, RM, Macario, KD, Gomes, PRS, Linares, R, Queiroz, E, Carvalho, C. 2013. Towards a complete 14C AMS facility at the Universidade Federal Fluminense (Niterói, Brazil): sample preparation laboratory tests. Nuclear Instruments and Methods in Physics Research B 294:173175.
Jou, RM, Macario, KD, Carvalho, C, Dias, RS, Brum, MC, Cunha, FR, Ferreira, CG, Chanca, IS. 2015. Biogenic fraction in the synthesis of polyethylene terephthalate. International Journal of Mass Spectrometry 388:6568.
Kim, SH, Kelly, PB, Clifford, AJ. 2008. Biological/biomedical accelerator mass spectrometry targets. 1. optimizing the CO2 reduction step using zinc dust. Analytical Chemistry 80(20):76517660.
Kim, SH, Kelly, PB, Clifford, AJ. 2009. Accelerator mass spectrometry targets of submilligram carbonaceous samples using the high-throughput Zn reduction method. Analytical Chemistry 81(14):59495954.
Linares, R, Macario, KD, Santos, GM, Carvalho, C, dos Santos, HC, Gomes, PR, Castro, MD, Oliveira, FM, Alves, EQ. 2015. Radiocarbon measurements at LAC-UFF: recent performance. Nuclear Instruments and Methods in Physics Research B 361:341345.
Macario, KD, Gomes, PR, Anjos, RM, Carvalho, C, Linares, R, Alves, EQ, Oliveira, FM, Castro, MD, Chanca, IS, Silveira, MF, Pessenda, LC. 2013. The Brazilian AMS Radiocarbon Laboratory (LAC-UFF) and the intercomparison of results with CENA and UGAMS. Radiocarbon 55(2–3):325330.
Macario, KD, Oliveira, FM, Carvalho, C, Santos, GM, Xu, X, Chanca, IS, Alves, EQ, Jou, RM, Oliveira, MI, Pereira, BB, Moreira, V. 2015. Advances in the graphitization protocol at the Radiocarbon Laboratory of the Universidade Federal Fluminense (LAC-UFF) in Brazil. Nuclear Instruments and Methods in Physics Research B 361:402405.
Mann, WB. 1983. An international reference material for radiocarbon dating. Radiocarbon 25(2):519527.
Marzaioli, F, Borriello, G, Passariello, I, Lubritto, C, Cesare, ND, D’Onofrio, A, Terrasi, F. 2008. Zinc reduction as an alternative method for AMS radiocarbon dating: process optimization at CIRCE. Radiocarbon 50(1):139149.
McNichol, AP, Gagnon, AR, Jones, GA, Osborne, EA. 1992. Illumination of a black box: analysis of gas composition during graphite target preparation. Radiocarbon 34(3):321329.
Oliveira, FM, Araujo, CA, Macario, KD, Cid, AS. 2015. Radiocarbon analysis of the Torah scrolls from the National Museum of Brazil collection. Nuclear Instruments and Methods in Physics Research B 361:531534.
Oliveira, FM, Macario, KD, Pereira, BB, Buarque, A, Chivall, D, Alves, QA, Bronk Ramsey, C. 2016. Evaluation of sample preparation protocols for the radiocarbon dating of Tupiguarani pottery in Southeastern Brazil. Radiocarbon. This issue. DOI:10.1017/RDC.2016.58.
Rinyu, L, Molnár, M, Major, I, Nagy, T, Veres, M, Kimák, Á, Wacker, L, Synal, H-A. 2013. Optimization of sealed tube graphitization method for environmental C-14 studies using MICADAS. Nuclear Instruments and Methods in Physics Research B 294:270275.
Rozanski, K. 1991. Consultants’ group meeting on 14C reference materials for radiocarbon laboratories. February 18–20, Vienna, Austria. Internal Report. Vienna: IAEA.
Rozanski, K, Stichler, W, Gonfiantini, R, Scott, EM, Beukens, RP, Kromer, B, van der Plicht, J. 1992. The IAEA 14C Intercomparison Exercise 1990. Radiocarbon 34(3):506519.
Vogel, JS. 1992. Rapid production of graphite without contamination for biomedical AMS. Radiocarbon 34(3):344350.
Xu, X, Trumbore, SE, Zheng, S, Southon, JR, McDuffee, KE, Luttgen, M, Liu, JC. 2007. Modifying a sealed tube zinc reduction method for preparation of AMS graphite targets: reducing background and attaining high precision. Nuclear Instruments and Methods in Physics Research B 259(1):320329.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

  • ISSN: 0033-8222
  • EISSN: 1945-5755
  • URL: /core/journals/radiocarbon
Please enter your name
Please enter a valid email address
Who would you like to send this to? *



Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed