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<p>The accurate identification of elemental carbon (EC) sources in aerosol based on radiocarbon (<span class="inline-formula">¹⁴</span>C) depends on the method of EC isolation. The lack of aerosol EC reference materials with “true” <span class="inline-formula">¹⁴</span>C values makes it impossible to evaluate the accuracy of various methods for the analysis of <span class="inline-formula">¹⁴</span>C-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 <span class="inline-formula">¹⁴</span>C-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 EC<span class="inline-formula">_Hypy</span> and avoid charring, is a more effective and stable approach for the matrix-independent <span class="inline-formula">¹⁴</span>C quantification of EC in aerosols. The <span class="inline-formula">¹³</span>C-EC<span class="inline-formula">_Hypy</span> and non-fossil EC<span class="inline-formula">_Hypy</span> values of Standard Reference Material (SRM) 1649b were <span class="inline-formula">−24.9</span> ‰ and 11 %, respectively.</p>