Microgram level radiocarbon (14C) determination on carbonaceous particles in ice

Jenk, Theo; Szidat, Sönke; Schwikowski, Margit; Gäggeler, Heinz; Wacker, L; Synal, H; Saurer, M (2007). Microgram level radiocarbon (14C) determination on carbonaceous particles in ice. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 259(1), pp. 518-525. Amsterdam: Elsevier 10.1016/j.nimb.2007.01.196

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In climate research the interest on carbonaceous particles has increased over the last years because of their influence on the radiation balance of the earth. Nevertheless, there is a paucity of available data regarding their concentrations and sources in the past. Such data would be important for a better understanding of their effects and for estimating their influence on future climate. Here, a technique is described to extract carbonaceous particles from ice core samples with subsequent separation of the two main constituents into organic carbon (OC) and elemental carbon (EC) for analysis of their concentrations in the past. This is combined with further analysis of OC and EC 14C/12C ratios by accelerator mass spectrometry (AMS), what can be used for source apportionment studies of past emissions. We further present how 14C analysis of the OC fraction could be used in the future to date any ice core extracted from a high-elevation glacier. Described sample preparation steps to final analysis include the combustion of micrograms of water–insoluble carbonaceous particles, primary collected by filtration of melted ice samples, the graphitisation of the obtained CO2 to solid AMS target material and final AMS measurements. Possible fractionation processes were investigated for quality assurance. Procedural blanks were reproducible and resulted in carbon masses of 1.3 ± 0.6 μg OC and 0.3 ± 0.1 μg EC per filter. The determined fraction of modern carbon (fM) for the OC blank was 0.61 ± 0.13. The analysis of processed IAEA-C6 and IAEA-C7 reference material resulted in fM = 1.521 ± 0.011 and δ13C = −10.85 ± 0.19‰, and fM = 0.505 ± 0.011 and δ13C = −14.21 ± 0.19‰, respectively, in agreement with consensus values. Initial carbon contents were thereby recovered with an average yield of 93%.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Departement of Chemistry and Biochemistry
08 Faculty of Science > Other Institutions > Teaching Staff, Faculty of Science

UniBE Contributor:

Jenk, Theo; Szidat, Sönke; Schwikowski, Margit and Gäggeler, Heinz

Subjects:

500 Science > 570 Life sciences; biology
500 Science > 540 Chemistry

ISSN:

0168-583X

Publisher:

Elsevier

Language:

English

Submitter:

Factscience Import

Date Deposited:

04 Oct 2013 14:53

Last Modified:

14 Mar 2016 12:52

Publisher DOI:

10.1016/j.nimb.2007.01.196

Web of Science ID:

000247535600095

BORIS DOI:

10.7892/boris.22423

URI:

https://boris.unibe.ch/id/eprint/22423 (FactScience: 34608)

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