中国望都地区夏季大气气溶胶挥发性特征

采用热扩散管与气溶胶质谱联用系统对2014年夏季河北望都乡村点位亚微米级气溶胶进行在线测量，获取了两段污染过程的气溶胶化学组成及挥发性特征：相对低污染期气溶胶平均质量浓度为（23.3±15.1）·g/m³，有机物占主导，主要受偏北方向气团影响；重污染期平均浓度为（86.6±19.7）·g/m³，硫酸盐占主导，受偏南方向气团影响；主要化学组分挥发性顺序均为硝酸盐 > 氯盐 > 铵盐 > 有机物 > 硫酸盐；与相对低污染期相比，重污染期的硫酸盐对质量浓度贡献更高且挥发性降低，而硝酸盐表现出更高的挥发性；对有机气溶胶而言，重污染期有机物氧化态更高且挥发性更低，老化特征明显.气溶胶半挥发性特征反映了华北夏季高污染条件下区域传输的重要作用.

Characterization of atmospheric aerosol volatility in North China during summertime

Thermal denuder-aerosol mass spectrometer (TD-AMS) system was utilized to measure the aerosol chemical composition and volatility in the summer of 2014 in Wangdu, a rural site in North China Plain, and data of two different episodes were collected:average PM₁ mass concentration of relatively low pollution episodes (ep1) was (23.3 ±15.1)·g/m³, dominated by sulfate, mainly influenced by air masses from the north; while (86.6 ±19.7)·g/m³ during high pollution episodes (ep2), dominated by organics aerosol (OA), influenced by air masses from the south; the volatility sequence of chemical species was nitrate > chloride > ammonia > organic matter>sulfate; when compared with ep1, during ep2, sulfate had a higher contribution for PM₁ and was less volatile, and nitrate was more volatile; OA during ep2 was less oxidized and showed lower volatility, indicating it was more aged. The semi-volatility of atmospheric aerosol suggested that regional transport played a key role under high pollution conditions in North China during summer.