Real-time monitoring of volatile elements existing in the atmosphere as gas components or nano-particles

2022 Fiscal Year Final Research Report

• Project/Area Number: 17K05909
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Analytical chemistry
• Research Institution: Chuo University
• Principal Investigator: Furuta Naoki 中央大学, 理工学部, 名誉教授 (90101055)
• Project Period (FY): 2017-04-01 – 2023-03-31
• Keywords: PM0.1大気粉塵 / リアルタイムリングリング / ガス交換器 (GED) / ICPMS / 揮発性元素 / ガス粒子化装置 (GPD) / 発生源の解明

Outline of Final Research Achievements

On the mass bases, the radial distribution of airborne particulates has two peaks at 0.5 μm and 6.0 μm, but on the number bases, there is only one peak at 0.05 μm. Abundant airborne particulates less than 0.1 μm, which is called as PM0.1, exist in the atmosphere. To investigate the origin of PM0.1, PM0.1 was collected on a filter using a nano-sampler, and the constituents were analyzed. As a result. 1/3 is ammonium sulfate, 1/3 is carbon, and 1/3 is major and trace elements.
PM0.1 particles were observed by Scanning Electron Microscope. We could see two kinds of particles. One is a string of carbon particles and the other is a spherical soft particle containing sulfur. The string of particles was diesel exhaust particles, and a spherical soft particle was a droplet of ammonium sulfate.

Free Research Field

Analytical Chemistry and Environmental Chemistry

Academic Significance and Societal Importance of the Research Achievements

大気粉塵の粒径分布を重量濃度でプロットすると、0.5 μmと6.0 μmにピークを持つ二山になりますが、数濃度でプロットすると、0.05 μmにピークを持つ一山となります。大気中には0.1 μm以下の大気粉塵（PM0.1）が圧倒的に多いのです。ヒトがこのPM0.1粒子を吸い込むと、肺の奥深くまで入り込み人体に悪影響を及ぼします。
本研究では、PM0.1の起源を明らかにしました。PM0.1粒子には2種類あります。一つは、数珠状に繋がった炭素粒子であり、ディーゼル排ガス粒子です。もう一つは、球形のイオウを含むソフトな粒子であり、硫酸アンモニウムの液滴でした。