Ultra-small graphitization reactors for ultra-microscale 14C analysis at the National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS) Facility
Shah Walter, Sunita R.
Gagnon, Alan R.
Roberts, Mark L.
McNichol, Ann P.
Lardie Gaylord, Mary C.
MetadataShow full item record
KeywordUltra-microscale; Carbon dioxide; Graphite; Accelerator mass spectroscopy; Methods; Sample preparation
In response to the increasing demand for 14C analysis of samples containing less than 25 µg C, ultra-small graphitization reactors with an internal volume of ~0.8 mL were developed at NOSAMS. For samples containing 6 to 25 µg C, these reactors convert CO2 to graphitic carbon in approximately 30 min. Although we continue to refine reaction conditions to improve yield, the reactors produce graphite targets that are successfully measured by AMS. Graphite targets produced with the ultra-small reactors are measured by using the Cs sputter source on the CFAMS instrument at NOSAMS where beam current was proportional to sample mass. We investigated the contribution of blank carbon from the ultra-small reactors and estimate it to be 0.3 ± 0.1 µg C with an Fm value of 0.43 ± 0.3. We also describe equations for blank correction and propagation of error associated with this correction. With a few exceptions for samples in the range of 6 to 7 µg C, we show that corrected Fm values agree with expected Fm values within uncertainty for samples containing 6–100 µg C.
© The Arizona Board of Regents on behalf of the University of Arizona, 2015. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Radiocarbon 57, no. 1 (2015): 109–122, doi:10.2458/azu_rc.57.18118.
Suggested CitationRadiocarbon 57, no. 1 (2015): 109–122
The following license files are associated with this item:
Showing items related by title, author, creator and subject.
Elder, Kathryn L.; Roberts, Mark L.; Lardie Gaylord, Mary C. (2017)We present a low-cost, high-throughput method for converting many types of organic samples into graphite. The method combines sample combustion and graphitization in a single process. Using a modified sealed graphitization ...
Chemical composition of the graphitic black carbon fraction in riverine and marine sediments at sub-micron scales using carbon X-ray spectromicroscopy Haberstroh, Paul R.; Brandes, Jay A.; Gelinas, Yves; Dickens, Angela F.; Wirick, Sue; Cody, George D. (2005-12-01)The chemical composition of the graphitic black carbon (GBC) fraction of marine organic matter was explored in several marine and freshwater sedimentary environments along the west coast of North America and the Pacific ...
Dorman, Craig E. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1971-10)The objective of this study was to describe the mechanics of wind wave generation and spectral development. Intermittency, high frequency microstructure in wind and wave fields, and strong nonlinear coupling involving a ...