Chemical composition and source apportionment of water-soluble organic matter in PM2.5

2018 Fiscal Year Final Research Report

• Project/Area Number: 17K12829
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Environmental impact assessment
• Research Institution: Japan Automobile Research Institute
• Principal Investigator: Suto Nana 一般財団法人日本自動車研究所, エネルギ・環境研究部, 研究員 (70791424)
• Project Period (FY): 2017-04-01 – 2019-03-31
• Keywords: 粒子状物質 / 水溶性有機炭素 / 安定同位体比 / 発生源推定 / 有機エアロゾル

Outline of Final Research Achievements

Water-soluble organic carbon (WSOC) is formed by oxidation of organic compounds in particulate matter. Stable carbon isotope ratio (δ13C) analysis is widely used to identify the sources of particulate matter, but determining the δ13C values of WSOC is complicated and requires a time‐consuming pretreatment process. This study tried to develop an online method for determining the δ13C values of WSOC in PM2.5 by means of wet oxidation/isotope ratio mass spectrometry. This simple method is quick because the paritulate matter is collected with a quartz fiber filter, extracted with water, and then analyzed without pretreatment. The quantitative method showed low blank levels for the analysis of the WSOC in atmospheric samples. Using this method, we determined δ13C values of WSOC in PM2.5 samples collected in Japan during the period from July to November 2017 and found that the values ranged from -26.5‰ to -25.0‰.

Free Research Field

環境分析学

Academic Significance and Societal Importance of the Research Achievements

PM2.5は国内の発生源のほかにも，国外からの越境汚染が問題視されている。本研究で構築した水溶性有機炭素の安定同位体比測定技術は，複数の発生源を切り分けることのできる手法である。そのため学術的に大きな役割と意義がある。また，本研究で構築した測定技術は，河川や海水，土壌などの環境分野への応用が可能である。さらに将来的には，これらの技術を用いて，食品の偽装問題，スポーツドーピング，医薬品分野など他の分野への応用や分析技術の革新につながる可能性があると考えている。