气候变化领域集成服务门户(CCPortal): Deconvolution of FIGAERO-CIMS thermal desorption profiles using positive matrix factorisation to identify chemical and physical processes during particle evaporation

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DOI	10.5194/acp-20-7693-2020
	Deconvolution of FIGAERO-CIMS thermal desorption profiles using positive matrix factorisation to identify chemical and physical processes during particle evaporation
	Buchholz A.; Ylisirniö A.; Huang W.; Mohr C.; Canagaratna M.; Worsnop D.R.; Schobesberger S.; Virtanen A.
发表日期	2020
ISSN	1680-7316
起始页码	7693
结束页码	7716
卷号	20 期号:13
英文摘要	The measurements of aerosol particles with a filter inlet for gases and aerosols (FIGAERO) together with a chemical ionisation mass spectrometer (CIMS) yield the overall chemical composition of the particle phase. In addition, the thermal desorption profiles obtained for each detected ion composition contain information about the volatility of the detected compounds, which is an important property for understanding many physical properties like gas particle partitioning. We coupled this thermal desorption method with isothermal evaporation prior to the sample collection to investigate the chemical composition changes during isothermal particle evaporation and particulate-waterdriven chemical reactions in-pinene secondary organic aerosol (SOA) of three different oxidative states. The thermal desorption profiles of all detected elemental compositions were then analysed with positive matrix factorisation (PMF) to identify the drivers of the chemical composition changes observed during isothermal evaporation. The keys to this analysis were to use the error matrix as a tool to weight the parts of the data carrying most information (i.e. the peak area of each thermogram) and to run PMF on a combined data set of multiple thermograms from different experiments to enable a direct comparison of the individual factors between separate measurements. The PMF was able to identify instrument background factors and separate them from the part of the data containing particle desorption information. Additionally, PMF allowed us to separate the direct desorption of compounds detected at a specific elemental composition from other signals with the same composition that stem from the thermal decomposition of thermally instable compounds with lower volatility. For each SOA type, 7 9 factors were needed to explain the observed thermogram behaviour. The contribution of the factors depended on the prior isothermal evaporation. Decreased contributions from the factors with the lowest desorption temperatures were observed with increasing isothermal evaporation time. Thus, the factors identified by PMF could be interpreted as volatility classes. The composition changes in the particles due to isothermal evaporation could be attributed to the removal of volatile factors with very little change in the desorption profiles of the individual factors (i.e. in the respective temperatures of peak desorption, Tmax). When aqueous-phase reactions took place, PMF was able to identify a new factor that directly identified the ions affected by the chemical processes. We conducted a PMF analysis of the FIGAERO CIMS thermal desorption data for the first time using laboratorygenerated SOA particles. But this method can be applied to, for example, ambient FIGAERO CIMS measurements as well. There, the PMF analysis of the thermal desorption data identifies organic aerosol (OA) sources (such as biomass burning or oxidation of different precursors) and types, e.g. hydrocarbon-like (HOA) or oxygenated organic aerosol (OOA). This information could also be obtained with the traditional approach, namely the PMF analysis of the mass spectra data integrated for each thermogram. But only our method can also obtain the volatility information for each OA source and type. Additionally, we can identify the contribution of thermal decomposition to the overall signal. © 2020 Copernicus GmbH. All rights reserved.
语种	英语
scopus关键词	aerosol; aerosol composition; atmospheric chemistry; biomass burning; concentration (composition); desorption; evaporation; particulate matter; source apportionment; temperature anomaly
来源期刊	Atmospheric Chemistry and Physics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/141242
作者单位	Department of Applied Physics, University of Eastern Finland, Kuopio, Finland; Institute of Meteorology and Climate Research, Karlsruhe Institute of Technology, Karlsruhe, Germany; Department of Environmental Science and Analytical Chemistry, Stockholm University, Stockholm, Sweden; Aerodyne Research Inc., Billerica, MA 08121, United States
推荐引用方式 GB/T 7714	Buchholz A.,Ylisirniö A.,Huang W.,et al. Deconvolution of FIGAERO-CIMS thermal desorption profiles using positive matrix factorisation to identify chemical and physical processes during particle evaporation[J],2020,20(13).
APA	Buchholz A..,Ylisirniö A..,Huang W..,Mohr C..,Canagaratna M..,...&Virtanen A..(2020).Deconvolution of FIGAERO-CIMS thermal desorption profiles using positive matrix factorisation to identify chemical and physical processes during particle evaporation.Atmospheric Chemistry and Physics,20(13).
MLA	Buchholz A.,et al."Deconvolution of FIGAERO-CIMS thermal desorption profiles using positive matrix factorisation to identify chemical and physical processes during particle evaporation".Atmospheric Chemistry and Physics 20.13(2020).