Characterization of chemical dynamics of new particle formation based on the development and application of novel collection method for ultra-fine aerosols

2020 Fiscal Year Final Research Report

• Project/Area Number: 18H03355
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 63010:Environmental dynamic analysis-related
• Research Institution: Kanazawa University
• Principal Investigator: Matsuki Atsushi 金沢大学, 環日本海域環境研究センター, 准教授 (90505728)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 大気エアロゾル / 新粒子生成 / ナノ粒子 / 雲凝結核

Outline of Final Research Achievements

The chemical speciation of nanoparticles is technically challenging because of the minute particle mass. There is a constant need for more effective collection method and sensitive chemical analysis, which can detect and resolve the chemical evolution of the nanoparticles in the atmosphere. This study proposed a novel technique that employs the SERS (Surface Enhanced Raman Spectroscopy) substrate as the sampling substrate of a condensational growth tube (CGT) sampler. This new experimental setup ensures simultaneous inertial sampling and SERS pretreatment of individual nanoparticles. Based on the successful detection of the peaks corresponding to sulfate v(SO42-) and organic v(C-H) modes, our proposed method showed sensitivity high enough for detecting major chemical components from individual nanoparticles as small as 20 nm. This can be a significant step forward in our pursuit of developing the more sensitive chemical analysis.

Free Research Field

大気環境科学

Academic Significance and Societal Importance of the Research Achievements

大気中の微量なガスが前駆物質となって粒子化する新粒子生成（NPF）は、最終的に雲凝結核の濃度を決定付け、地球の気候に影響を与える大気エアロゾルの重要な発生プロセスである。しかし、質量の極めて小さい新粒子（ナノ粒子）の検出に十分な感度を持った測定法がなかったために、プロセスに関与する化学成分についての理解が進んでいない現状があった。以上の結果は、従来の分光学的な粒子分析の検出限界サイズを従来に比べ1桁近く大幅に更新する画期的な成果であり、今後、実大気エアロゾルへのさらなる応用を通じて、新粒子生成プロセスの解明、ならびに気候影響の評価に大きな貢献が期待される。