Towards radiocarbon dating of single foraminifera with a gas ion source
Carbonate shells from foraminifera are often analysed for radiocarbon to determine the age of deep-sea sediments or to assess radiocarbon reservoir ages. However, a single foraminiferal test typically contains only a few micrograms of carbon, while most laboratories require more than 100μg for radio...
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| Main Authors: | , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
January 2013
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| In: |
Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms
Year: 2013, Volume: 294, Pages: 307-310 |
| ISSN: | 1872-9584 |
| DOI: | 10.1016/j.nimb.2012.08.038 |
| Online Access: | Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1016/j.nimb.2012.08.038 Verlag, lizenzpflichtig, Volltext: https://www.sciencedirect.com/science/article/pii/S0168583X12005642 
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| Author Notes: | L. Wacker, J. Lippold, M. Molnár, H. Schulz |
| Summary: | Carbonate shells from foraminifera are often analysed for radiocarbon to determine the age of deep-sea sediments or to assess radiocarbon reservoir ages. However, a single foraminiferal test typically contains only a few micrograms of carbon, while most laboratories require more than 100μg for radiocarbon dating with an accelerator mass spectrometry (AMS) system. The collection of the required amount of foraminifera for a single analyses is therefore time consuming and not always possible. Here, we present a convenient method to measure the radiocarbon content of foraminifera using an AMS system fitted with a gas ion source. CO2 is liberated from 150 to 1150μg of carbonate in septum sealed vials by acid decomposition of the carbonate. The CO2 is collected on a zeolite trap and subsequently transferred to a syringe from where it is delivered to the ion source. A sample of 400μg (50μgC) typically gives a 12C− ion source current of 10-15μA over 20min, yielding a measurement precision of less than 7 per mil for a modern sample. Using this method, we were able to date a single 560μg Cibicides pseudoungerianus test at 14,030±160 radiocarbon years. Only a minor modification to our existing gas handling system was required and the system is fully automatable to further reduce the effort involved for sample preparation. |
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| Item Description: | Available online 20 September 2012 Gesehen am 28.07.2021 |
| Physical Description: | Online Resource |
| ISSN: | 1872-9584 |
| DOI: | 10.1016/j.nimb.2012.08.038 |