Transboundary Secondary Organic Aerosol in Western Japan Indicated by the 未13C of Water-Soluble Organic Carbon and the m/z 44 Signal in Organic Aerosol Mass Spectra

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• 作者：Satoshi Irei ; Akinori Takami ; Masahiko Hayashi ; Yasuhiro Sadanaga ; Keiichiro Hara ; Naoki Kaneyasu ; Kei Sato ; Takemitsu Arakaki ; Shiro Hatakeyama ; Hiroshi Bandow ; Toshihide Hikida ; Akio Shimono
• 刊名：Environmental Science & Technology
• 出版年：2014
• 出版时间：June 3, 2014
• 年：2014
• 卷：48
• 期：11
• 页码：6273-6281
• 全文大小：344K
• 年卷期：v.48,no.11(June 3, 2014)
• ISSN：1520-5851

文摘

The stable carbon isotope ratio (未¹³C) of low-volatile water-soluble organic carbon (LV-WSOC) was measured in filter samples of total suspended particulate matter, collected every 24 h in the winter of 2010 at an urban site and two rural sites in western Japan. Concentrations of the major chemical species in fine aerosol (<1.0 渭m) were also measured in real time by aerosol mass spectrometers. The oxidation state of organic aerosol was evaluated using f₄₄; i.e., the proportion of the signal at m/z 44 (CO₂⁺ ions from the carboxyl group) to the sum of all m/z signals in the organic mass spectra. A strong correlation between LV-WSOC and m/z 44 concentrations was observed, which suggested that LV-WSOC was likely to be associated with carboxylic acids in fine aerosol. Plots of 未¹³C of LV-WSOC versus f₄₄ showed random variation at the urban site and systematic trends at the rural sites. The systematic trends qualitatively agreed with a simple binary mixture model of secondary organic aerosol with background LV-WSOC with an f₄₄ of 0.08 and 未¹³C of 鈭?7鈥?or higher. Comparison with reference values suggested that the source of background LV-WSOC was likely to be primary emissions associated with C₄ plants.