Technical note: Intercomparison Study of the EC Radiocarbon Analysis Methods Using Synthetic Known Samples

Abstract. The accurate identification of elemental carbon (EC) source 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 separation 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 separation method but also to the types and proportions of biomass sources in the sample. And the Hydropyrolysis (Hypy) method, which can be used to separate 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 SRM1649b was 24.9 ‰ and 11 %, respectively.