中文摘要：

元素碳示踪物法（The EC tracer method）因其简单易行被广泛应用于区分有机气溶胶的一次和二次来源.本文以源排放复杂的北京城区（冬夏两季）和山东长岛作为城市和偏远地区的代表,利用气溶胶质谱仪（AMS）和碳黑测定仪等多种仪器的观测结果,基于元素碳示踪物法估算了在这些地区二次源对有机碳的贡献,并将该结果和同观测受体模型正定矩阵因子分析（PMF）的结果进行比较.探讨了北京地区餐饮源和生物质燃烧源对元素碳示踪物法估算二次有机碳的影响.本研究指明了元素碳示踪物法基本假设在源复杂地区应用的局限性,利用该方法对二次有机气溶胶估算会因存在具有较高OC/EC比值的一次排放源,而有一定偏差（例如本论文10%~40%）.该研究对其他的元素示踪物法的估算工作具有一定的借鉴意义.

英文摘要：

The EC tracer method is widely used to estimate secondary fractions of organic carbon（ OC） for the simplicity of this method. In this study,concentrations of secondary OC（ SOC） at an urban site of Beijing（ winter and summer） and a downwind site of Changdao island（ spring） have been estimated based on the EC tracer method. In each campaign,OC and black carbon（ BC） used in this method were measured by a high-resolution time-offlight aerosol mass spectrometer（ HR-To F-AMS） and optical instruments（ e. g. MAAP or Aethalometer） at time resolutions of several minutes,respectively. By comparing the estimated SOC with these from positive matrix factorization（ PMF） method,we found large uncertainties（ e.g. 10% ~ 40%in this study） in the EC tracer method due to primary emissions from cooking and / or biomass burnings,of which OC / EC ratios are similar to these from secondary formations. This work points out the limitation of the EC tracer method in the regions with complicated sources,and the findings can be a reference to other related studies.