Technical note: Intercomparison study of the elemental carbon radiocarbon analysis methods using synthetic known samples

Abstract

Abstract. The accurate identification of elemental carbon (EC) sources in aerosol based on radiocarbon (14C) depends on the method of EC isolation. The lack of aerosol EC reference materials with “true” 14C values makes it impossible to evaluate the accuracy of various methods for the analysis of 14C-EC in aerosols. In this study, EC isolation methods were evaluated by using samples of mixed biomass burning, vehicle exhaust, and coal combustion. The results show that 14C-EC was not only related to the isolation method but also to the types and proportions of biomass sources in the sample. The hydropyrolysis (Hypy) method, which can be used to isolate a highly stable portion of ECHypy and avoid charring, is a more effective and stable approach for the matrix-independent 14C quantification of EC in aerosols. The 13C-ECHypy and non-fossil ECHypy values of Standard Reference Material (SRM) 1649b were −24.9 ‰ and 11 %, respectively.

Provenance of Aerosol Black Carbon over Northeast Indian Ocean and South China Sea and Implications for Oceanic Black Carbon Cycling

“…First, the δ 13 C− Δ 14 C values measured by the HyPy and BPCA methods are comparable as the HyPy and BPCA methods shared similar dual-carbon isotope compositions in the same reference materials (Table S8, see detailed method comparison in Text S6). ,, However, the comparison of the two techniques in the reference substance is currently limited to one reference material (Text S6 and Table S8). More investigation is therefore needed on BC method comparison in terms of both quantification and dual-carbon isotope compositions, especially for the method comparison in multiple commercial/environmental reference materials with different phase states.…”

“…The residual carbon is defined as BC in the present study. BC determined by HyPy can overcome issues associated with the interference of BC from organic carbon charring due to the reduced environment. , …”

“…BC determined by HyPy can overcome issues associated with the interference of BC from organic carbon charring due to the reduced environment. 29,35 Carbon Abundance and Stable Isotope Composition. The abundance and δ 13 C of total organic carbon in pre-HyPy samples and BC in post-HyPy samples were determined by a Costech Elemental Analyzer (Costech Analytical Technologies Inc., Valencia, CA, USA) fitted with a Zero Blank autosampler (Costech Analytical Technologies Inc.).…”