Department of Earth and Environmental Science, Graduate School of Environmental Studies, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan.
Environ Sci Technol. 2011 Nov 1;45(21):9168-74. doi: 10.1021/es201271w. Epub 2011 Oct 5.
To characterize atmospheric particulate organics with respect to polarity, aerosol samples collected on filters in the urban area of Nagoya, Japan, in 2009 were extracted using water, methanol, and ethyl acetate. The extracts were atomized and analyzed using a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) and a hygroscopicity tandem differential mobility analyzer. The atmospheric concentrations of the extracted organics were determined using phthalic acid as a reference material. Comparison of the organic carbon concentrations measured using a carbon analyzer and the HR-ToF-AMS suggests that organics extracted with water (WSOM) and ethyl acetate (EASOM) or those extracted with methanol (MSOM) comprise the greater part of total organics. The oxygen-carbon ratios (O/C) of the extracted organics varied: 0.51-0.75 (WSOM), 0.37-0.48 (MSOM), and 0.27-0.33 (EASOM). In the ion-group analysis, WSOM, MSOM, and EASOM were clearly characterized by the different fractions of the CH and CO(2) groups. On the basis of the hygroscopic growth measurements of the extracts, κ of organics at 90% relative humidity (κ(org)) were estimated. Positive correlation of κ(org) with O/C (r 0.70) was found for MSOM and EASOM, but no clear correlation was found for WSOM.
为了描述大气颗粒物中有机物的极性，于 2009 年在日本名古屋市区用滤膜采集气溶胶样品，用去离子水、甲醇和乙酸乙酯提取。提取物经雾化后，使用高分辨率飞行时间气溶胶质谱仪（HR-ToF-AMS）和吸湿串联差分迁移率分析仪进行分析。采用邻苯二甲酸作为参考物质，确定提取有机物的大气浓度。用碳分析仪和 HR-ToF-AMS 测量的有机碳浓度的比较表明，用去离子水（WSOM）和乙酸乙酯（EASOM）提取的有机物或用甲醇（MSOM）提取的有机物占总有机物的大部分。提取有机物的氧碳比（O/C）变化范围为 0.51-0.75（WSOM）、0.37-0.48（MSOM）和 0.27-0.33（EASOM）。在离子组分析中，WSOM、MSOM 和 EASOM 明显由 CH 和 CO2 基团的不同部分特征化。基于提取物的吸湿性增长测量，估算了 90%相对湿度下有机物的κ值（κ(org)）。对于 MSOM 和 EASOM，发现 κ(org)与 O/C（r 0.70）之间存在正相关，但在 WSOM 中没有发现明显的相关性。
