Microgram-Level Radiocarbon Determination of Carbonaceous Particles in Firn and Ice Samples

Pretreatment and OC/EC Separation

Bibliographic Data

ID9243365
AuthorsFang Cao (0000-0001-8840-8454), Yan-Lin Zhang, Sönke Szidat (0000-0002-1824-6207), Alexander Zapf, Lukas Wacker (0000-0002-8215-2678), Margit Schwikowski (0000-0002-0856-5183)
Year2013
Volume55
Issue3–4
Publication date2013-01-01
Open AccessNo
TypeARTICLE
VenueRadiocarbon (JOURNAL)
Journal identifiersISSN: 0033-8222 • E-ISSN: 1945-5755
PublisherCambridge University Press (CUP) (PUBLISHER)
DOI10.2458/azu_js_rc.55.16291
OpenAlexW4241438524, W2128979352
LanguageEN
Citations received1
References cited23

Carbonaceous particles that comprise organic carbon (OC) and elemental carbon (EC) are of increasing interest in climate research because of their influence on the radiation balance of the Earth. The radiocarbon determination of particulate OC and EC extracted from ice cores provides a powerful tool to reconstruct the long-term natural and anthropogenic emissions of carbonaceous particles. However, this 14 C-based source apportionment method has not been applied for the firn section, which is the uppermost part of Alpine glaciers with a typical thickness of up to 50 m. In contrast to glacier ice, firn samples are more easily contaminated through drilling and handling operations. In this study, an alternative decontamination method for firn samples consisting of chiselling off the outer parts instead of rinsing them was developed and verified. The obtained procedural blank of 2.8 ± 0.8 μg C for OC is a factor of 2 higher compared to the rinsing method used for ice, but still relatively low compared to the typical OC concentration in firn samples from Alpine glaciers. The EC blank of 0.3 ± 0.1 μg C is similar for both methods. For separation of OC and EC for subsequent 14 C analysis, a thermal-optical method instead of the purely thermal method was applied for the first time to firn and ice samples, resulting in a reduced uncertainty of both the mass and 14 C determination. OC and EC concentrations as well as their corresponding fraction of modern for firn and ice samples from Fiescherhorn and Jungfraujoch agree well with published results, validating the new method

Climatology · Firn · Geomorphology · Glacier · Ice core · Mineralogy · Radiocarbon dating · Snow · Atmospheric chemistry and aerosols · Chemistry · Cryospheric studies and observations · Geology and Paleoclimatology Research · Isotope Analysis in Ecology · Toxic Organic Pollutants Impact · Environmental Chemistry · Geology

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