Analysis of the mixing state of airborne particles using a tandem combination of laser-induced fluorescence and incandescence techniques. (September 2015)

• Record Type: Journal Article
• Authors: Taketani, Fumikazu; Kanaya, Yugo; Nakamura, Takayuki; Takeda, Naoki; Koizumi, Kazuhiro; Hirayama, Noritomo; Miyakawa, Takuma; Pan, Xiaole; Moteki, Nobuhiro; Takegawa, Nobuyuki
• Is Part Of: Journal of aerosol science. Volume 87(2015:Sep.)
• Page Start: 102
• Page End: 110
• Publication Date: 2015-09
• Subjects: Black carbon -- Fluorescent particles -- Mixing state -- Single particles; Aerosols -- Periodicals; Aerosols -- Periodicals; Aérosols -- Périodiques; 541.34515
• DOI: 10.1016/j.jaerosci.2015.05.002
• Languages: English
• ISSNs: 0021-8502

Abstract

Abstract: We have developed a novel system for real-time measurement of the mixing state of aerosol particles using a tandem combination of laser-induced fluorescence (LIF) and incandescence (LII) techniques. The tandem analysis system comprises two chambers connected in series; particles are analyzed with LIF in the first chamber and LII in the second chamber. We analyzed identical particles using the two methods as judged by the time intervals of detection in the two chambers. This system provides information on the mixing state of fluorescent compounds and black carbon in single particles. Ground-based measurements of ambient particles were performed in Tokyo during October 26–29, 2012. We analyzed 43, 881 particles with optical diameters greater than 0.4 μm. The fractions of particles with fluorescent composition, black carbon, and both were 14.2%, 2.3%, and 0.3%, respectively, which indicates the presence of internal mixtures of black carbon and fluorescent species in the ambient air for the first time. Mixtures of biological materials (estimated from fluorescence patterns) and black carbon were also detected. The fluorescence patterns of single particles with and without black carbon were almost identical, suggesting that particles with both black carbon and fluorescent composition might be formed by aggregation in ambient air. Graphical abstract: Highlights: An instrument using tandem combination of LIF and LII techniques for identical particles was developed. Shell/core analysis could be carried out without any fitting. Individual particles (>0.4 μm) with fluorescent composition, BC, and both were successfully detected in the ambient air measurement by this system.