Advanced instrumental approaches for chemical characterization of indoor particulate matter

Figures & data

Figure 1. Levels of airborne PM components identification related to the research need on atmospheric behavior, properties, and sources of PM components (n is the number of PM constituents identified and/or measured). n ≥ 100: identification of organic PM compounds according to their properties, such as functional group analysis; 10 ≥ n ≥ 100: real-time identification and monitoring of PM chemical composition (e.g., different organic aerosol categories and inorganic ions); n ≤ 10: identification of molecular markers of PM sources or formation processes (e.g., organic acids, saccharides, and aliphatic amines); and n ≤ 2 to 3: identification and quantification of specific molecular markers for assessing secondary organic aerosol (SOA) source processes (e.g., isoprene, α-pinene, and biomass burning SOA markers). Adapted from the review works of Nozière et al. ^[12] and Duarte and Duarte^[19].

Figure 2. Comparison of data provided by AMS and ATOFMS measurements. AMS provides bulk size-resolved non-refractory species [e.g., organics, sulfate (SO₄²⁻), nitrate (NO₃⁻), and ammonium (NH₄⁺)] mass fractions and concentrations for PM₁. Chemometric tools (i.e., PMF) has been used to resolve the organic component into different organic aerosol (OA) categories: hydrocarbon-like OA (HOA), low-volatility oxidized OA (LV-OOA), semi-volatile OOA (SV-OOA), and biomass burning OA (BBOA). ATOFMS also reports size-resolved number fractions/concentrations and provides the mixing state of individual particles, allowing to discern the distribution of secondary species on primary particles: schematic examples of primary particles are shown for sub-µm (organic carbon (OC), elemental carbon (EC), biomass burning (BB)) and super-µm (sea salt and dust) particles, including examples of mixing with secondary species, including SO₄²⁻, NO₃⁻, NH₄⁺, and oxidized OC. Modified and reproduced with permission from Pratt and Prather.^[15] Copyright 2012 John Wiley & Sons, Inc.

Nozière, B.; Kalberer, M.; Claeys, M.; Allan, J.; D'Anna, B.; Decesari, S.; Finessi, E.; Glasius, M.; Grgić, I.; Hamilton, J. F.; et al. The Molecular Identification of Organic Compounds in the Atmosphere: State of the Art and Challenges. Chem. Rev. 2015, 115, 3919–3983. doi:10.1021/cr5003485

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Duarte, R. M. B. O.; Duarte, A. C. 2017 NMR Studies of Organic Aer osols. In Annual Reports on NMR Spectroscopy, Webb, G.A., Ed., Academic Press: Oxford, pp 83–135.

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Pratt, K. A.; Prather, K. A. Mass Spectrometry of Atmospheric Aerosols-Recent Developments and Applications. Part II: On-Line Mass Spectrometry Techniques. Mass Spectrom. Rev. 2012, 31, 17–48. doi:10.1002/mas.20330

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