Wang Yang-jun, Dong Ya-ping, Feng Jia-liang, Guan Jing-jing, Zhao Wei, Li Huai-jian
School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China.
Huan Jing Ke Xue. 2010 Aug;31(8):1755-61.
Organic carbon (OC) and elemental carbon (EC) in PM2.5 samples collected in urban (Xujiahui) and industrial (Baoshan) areas in Shanghai during 2007-2008 were analyzed with a DRI carbon analyzer using IMPROVE-TOR protocol. The results showed that the seasonal average concentrations of OC and EC were highest in the winter and lowest in the summer. The annual average concentrations of OC and EC were 8.10 and 3.91 microg x m(-3) at the urban sampling site, and 11.91 and 4.69 microg x m(-3) in the industrial area. The annual average OC/EC ratios at the two sites were 2.01 and 2.42, respectively. Strong correlations (R2 0.52-0.87) between OC and EC were found in all seasons, with the highest correlation coefficients in the winter ( R2 0.87 and 0.80) and the lowest in the spring (R2 0.52 and 0.58), indicating that the pollutant sources in spring was more complicated due to the varying wind directions. The annual average concentrations of secondary organic carbon (SOC) were 2.72 and 5.07 microg x m(-3) at the urban and industrial sites, accounting for about 30% of the total OC. The contribution of SOC to OC was the highest (about 40%) in the summer, in accordance with the high temperature and strong solar radiation in the summer. It was also found that precipitation had significant impact on the concentrations of OC and EC, especially in the winter. The average concentrations during periods without precipitation were two times higher than that during periods with precipitation in the winter, whereas no significant difference was found between the concentrations of OC and EC in the periods with and without precipitation in the summer, possibly due to the more stable atmospheric conditions during the periods with precipitation in comparison with those without precipitation. The OC/EC and SOC/OC ratios decreased significantly during precipitation.
采用IMPROVE - TOR方法，利用DRI碳分析仪对2007 - 2008年期间在上海市区（徐家汇）和工业区（宝山）采集的PM2.5样本中的有机碳（OC）和元素碳（EC）进行了分析。结果表明，OC和EC的季节平均浓度在冬季最高，夏季最低。市区采样点OC和EC的年平均浓度分别为8.10和3.91微克·米-3，工业区分别为11.91和4.69微克·米-3。两个采样点的年平均OC/EC比值分别为2.01和2.42。在所有季节中，OC和EC之间均存在强相关性（R2为0.52 - 0.87），其中冬季的相关系数最高（R2分别为0.87和0.80），春季最低（R2分别为0.52和0.58），这表明由于风向多变，春季的污染物来源更为复杂。市区和工业区二次有机碳（SOC）的年平均浓度分别为2.72和5.07微克·米-3，约占总OC的30%。SOC对OC的贡献在夏季最高（约40%），这与夏季的高温和强太阳辐射相符。研究还发现，降水对OC和EC的浓度有显著影响，尤其是在冬季。冬季无降水期间的平均浓度比有降水期间高出两倍，而夏季有降水和无降水期间OC和EC的浓度没有显著差异，这可能是因为与无降水期间相比，有降水期间的大气条件更为稳定。降水期间OC/EC和SOC/OC比值显著下降。
