【摘要】 为了解南京地区大气细颗粒物及化学成分在灰霾期间的污染水平及可能来源,于2007年6月至2008年5月,采集PM_2.5样品,并测定了其中有机碳（OC）和元素碳（EC）的含量.并考察了有机碳和元素碳的季节变化特征,比较分析了南京地区灰霾与非灰霾期间含碳气溶胶的污染特征.结果显示,南京大气中PM_2.5、OC和EC浓度变化范围分别是12.1～287.1,2.6～47.0和1.0～33.6μg/m³,其中夏季PM_2.5（109.6μg/m³）和OC（20.8μg/m³）的值在四个季度中最高,呈现出夏季>秋季>冬季>春季的季节变化特征;EC则具有秋季>春季>冬季>夏季的季节变化特征.霾日的OC、EC、总碳含量（TC）浓度及OC与EC比值分别是非霾日的2.0、1.8、1.9和1.7倍.后向轨迹分析表明,在有利的天气背景下,具有丰富水汽和污染物的混合气团最易使南京产生霾天气.更多还原

【Abstract】 Chemical characteristics and possible sources of fine particular matter(PM_2.5) was investigated for 1 year in Nanjing.PM_2.5 was collected from June 2007 to May 2008,which carbonaceous species,organic carbon（OC） and elemental carbon（EC）,in the samples were analyzed.Seasonal variations of OC and EC concentrations were investigated; the pollution degree and characteristics of carbonaceous aerosols during haze and no haze period were analyzed and compared.Results showed that yearly PM_2.5 and carbonaceous concentrations varied in wide ranges with 12.1²87.1μg/m³ for PM_2.5,2.6～47.0μg/m³ for OC and 1.0³3.6μg/m³ for EC.On seasonal average,the highest PM_2.5 （109.6μg/m³） and OC（20.8μg/m³） levels occurred during summer.The seasonal average concentrations of PM_2.5 and organic carbon levels ranked by the order of summer>autumn>winter>spring,while the seasonal average concentrations of EC were in the order of autumn,spring,winter and summer.The OC/EC ratio and concentrations of carbonaceous species such as,OC,EC and total carbon（TC） in haze days were 1.7 2.0,1.8,and 1.9 times higher than those in non-haze days.Backward air trajectories indicated that haze formation in Nanjing was attributable to air masses with abundant water vapors and pollutants.更多还原