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Experiences from the production and homogeneity analysis of an AMS 14C sucrose standard for high-activity measurements

Sydoff, Marie LU and Stenström, Kristina LU (2010) Proceedings of the 20th International Radiocarbon Conference In Radiocarbon 52(3). p.1351-1357
Abstract
Accurate accelerator mass spectrometry (AMS) measurements rely on standards with well-known isotopic

ratios. For radiocarbon measurements, a number of standards with different properties are commercially available, of which

the IAEA-C6 sucrose standard with a 14C value of 150.61 pMC is the most active. When analyzing biological samples resulting

from studies using 14C-labeled substances, the activity content can be up to 100 times this value. Thus, there is a need for

a standard material with higher activity content than IAEA-C6 for making accurate AMS measurements on this type of sample.

This paper describes the attempts of producing a standard with an activity content of about 10 times modern... (More)
Accurate accelerator mass spectrometry (AMS) measurements rely on standards with well-known isotopic

ratios. For radiocarbon measurements, a number of standards with different properties are commercially available, of which

the IAEA-C6 sucrose standard with a 14C value of 150.61 pMC is the most active. When analyzing biological samples resulting

from studies using 14C-labeled substances, the activity content can be up to 100 times this value. Thus, there is a need for

a standard material with higher activity content than IAEA-C6 for making accurate AMS measurements on this type of sample.

This paper describes the attempts of producing a standard with an activity content of about 10 times modern carbon. The

material chosen has to be chemically inert, preferably non-toxic, commercially available in 14C-labeled form, and the activity

must be homogeneously distributed within the material. Two different standard materials were considered: urea and sucrose.

Sucrose was chosen for the new standard, since it is non-toxic, inexpensive, and organic and on combustion, forms only carbon

dioxide (CO2) and water (H2O). In this paper, we discuss our experience in the production and homogeneity analysis of

this material, from the crystallization of the sucrose solution to the graphitization of the samples. When using an online combustion

method and a septa-sealed vial reduction method, the AMS measurements indicated that the activity was not homogeneously

distributed throughout the material. Contrary to this, measurements of the sucrose solution prior to recrystallization

indicated that the activity was more homogeneously distributed before than after the recrystallization. In order to determine

whether the inhomogeneity depended on the graphitization method (i.e. the combustion or the reduction method) or on the

material itself, 3 different graphitization methods and 2 different methods of recrystallization were tested. (Less)
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author
organization
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
in
Radiocarbon
volume
52
issue
3
pages
1351 - 1357
publisher
University of Arizona
conference name
Proceedings of the 20th International Radiocarbon Conference
external identifiers
  • wos:000285437900051
ISSN
0033-8222
language
English
LU publication?
yes
id
4a273702-8a8f-4658-8c18-2cec5e1477cb (old id 1671020)
alternative location
http://digitalcommons.arizona.edu/restrictedobjectviewer?o=http://radiocarbon.library.arizona.edu/Volume52/Number3/97818f37-d565-4441-9970-e55d5e83d6bf
date added to LUP
2010-09-15 14:26:48
date last changed
2018-05-29 10:55:17
@inproceedings{4a273702-8a8f-4658-8c18-2cec5e1477cb,
  abstract     = {Accurate accelerator mass spectrometry (AMS) measurements rely on standards with well-known isotopic<br/><br>
ratios. For radiocarbon measurements, a number of standards with different properties are commercially available, of which<br/><br>
the IAEA-C6 sucrose standard with a 14C value of 150.61 pMC is the most active. When analyzing biological samples resulting<br/><br>
from studies using 14C-labeled substances, the activity content can be up to 100 times this value. Thus, there is a need for<br/><br>
a standard material with higher activity content than IAEA-C6 for making accurate AMS measurements on this type of sample.<br/><br>
This paper describes the attempts of producing a standard with an activity content of about 10 times modern carbon. The<br/><br>
material chosen has to be chemically inert, preferably non-toxic, commercially available in 14C-labeled form, and the activity<br/><br>
must be homogeneously distributed within the material. Two different standard materials were considered: urea and sucrose.<br/><br>
Sucrose was chosen for the new standard, since it is non-toxic, inexpensive, and organic and on combustion, forms only carbon<br/><br>
dioxide (CO2) and water (H2O). In this paper, we discuss our experience in the production and homogeneity analysis of<br/><br>
this material, from the crystallization of the sucrose solution to the graphitization of the samples. When using an online combustion<br/><br>
method and a septa-sealed vial reduction method, the AMS measurements indicated that the activity was not homogeneously<br/><br>
distributed throughout the material. Contrary to this, measurements of the sucrose solution prior to recrystallization<br/><br>
indicated that the activity was more homogeneously distributed before than after the recrystallization. In order to determine<br/><br>
whether the inhomogeneity depended on the graphitization method (i.e. the combustion or the reduction method) or on the<br/><br>
material itself, 3 different graphitization methods and 2 different methods of recrystallization were tested.},
  author       = {Sydoff, Marie and Stenström, Kristina},
  booktitle    = {Radiocarbon},
  issn         = {0033-8222},
  language     = {eng},
  number       = {3},
  pages        = {1351--1357},
  publisher    = {University of Arizona},
  title        = {Experiences from the production and homogeneity analysis of an AMS 14C sucrose standard for high-activity measurements},
  volume       = {52},
  year         = {2010},
}