scholarly journals Substantial organic impurities at the surface of synthetic ammonium sulfate particles

2021 ◽  
Author(s):  
Junteng Wu ◽  
Nicolas Brun ◽  
Juan Miguel González-Sánchez ◽  
Badr R’Mili ◽  
Brice Temime Roussel ◽  
...  

Abstract. Ammonium sulfate (AS) particles are widely used for studying the physical-chemistry processes of aerosols and for instrument calibrations. Small quantities of organic matter can greatly influence the studied properties, as observed by many laboratory studies. In this work, monodisperse particles (from 200 nm to 500 nm) were generated by nebulizing various AS solutions and organic impurities were quantified relative to sulfate using a High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS). The organic content found in AS solutions was also tentatively identified using a Liquid Chromatography–tandem Mass Spectrometry (LC-MS). The results from both analytical techniques were consistent and demonstrated that the organic impurities contained oxygen, nitrogen and/or sulfur, their molecular masses ranged from m/z 69 to 420, they likely originate from the commercial AS crystals. For AS particle sizes ranging from 200 nm to 500 nm, the total mass fraction of organic (relative to sulfate) ranged from 3.8 % to 1.5 % respectively. An inorganic-organic mixture model suggested that the organic impurities were coated on the AS particle surface with a density of 1.1 × 10−3 g m−2. A series of tests were performed to remove the organic content (using pure N2 in the flow, ultrapure water in the solutions, and very high AS quality), showing that at least 40 % of the organic impurities could be removed. In conclusion, it is recommended to use AS seeds with caution, especially when small particles are used, in terms of AS purity and water purity when aqueous solutions are used for atomization.

2004 ◽  
Vol 4 (1) ◽  
pp. 65-80 ◽  
Author(s):  
J. Schneider ◽  
S. Borrmann ◽  
A. G. Wollny ◽  
M. Bläsner ◽  
N. Mihalopoulos ◽  
...  

Abstract. Mass spectrometric analysis of volatile and semi-volatile (=non-refractory) aerosol particles have been performed during a field study in the summer Eastern Mediterranean. A size-resolved, quantitative mass spectrometric technique (the Aerodyne Aerosol Mass Spectrometer, AMS) has been used, and the results are compared to filter sampling methods and particle sizing techniques. The different techniques agree with the finding that the fine particle mode (D<1.2 mm) consisted mostly of ammonium sulfate and of organic material. The aerosol sulfate ranged between 2 and 12 mg/m3. On most days, ammonium was closely correlated with sulfate, suggesting ammonium sulfate as the major aerosol component, but on days with high sulfate mass concentrations, the sulfate was not fully neutralized by ammonium. Trajectories indicate that the aerosol and/or its precursors originate from South-Eastern Europe. The source of the ammonium sulfate aerosol is most likely fossil fuel burning, whereas the organic aerosol may also originate from biomass burning. Ion series analysis of the organics fraction in the mass spectrometer indicated that the major component of the organics were oxygenated organics which are a marker for aged, photochemically processed aerosol or biomass burning aerosol. The non-refractory aerosol compounds, measured with the Aerosol Mass Spectrometer, contributed between 37 and 50% to the total aerosol mass in the fine mode. A second mass spectrometer for single particle analysis by laser ablation has been used for the first time in the field during this study and yielded results, which agree with filter samples of the coarse particle mode. This mode consisted of sea salt particles and dust aerosol.


2003 ◽  
Vol 3 (4) ◽  
pp. 3907-3938
Author(s):  
J. Schneider ◽  
S. Borrmann ◽  
A. G. Wollny ◽  
M. Bläsner ◽  
N. Mihalopoulos ◽  
...  

Abstract. Mass spectrometric analysis of volatile and semi-volatile (= non-refractory) aerosol particles have been performed during a field study in the summer Eastern Mediterranean. A size-resolved, quantitative mass spectrometric technique (the Aerodyne Aerosol Mass Spectrometer, AMS) has been used, and the results are compared to filter sampling methods and particle sizing techniques. The different techniques agree with the finding that the fine particle mode (d<1.2 μm) consisted mostly of ammonium sulfate and of organic material. The aerosol sulfate ranged between 2 and 12 μg/m3. Ammonium was closely correlated with sulfate, suggesting ammonium sulfate as the major aerosol component, but the mass ratio of ammonium to sulfate indicated that sulfate was not fully neutralized by ammonium. Trajectories indicate that the aerosol and/or its precursors originate from South-Eastern Europe. The source of the ammonium sulfate aerosol is most likely fossil fuel burning, whereas the organic aerosol may also originate from biomass burning. Ion series analysis of the organics fraction in the mass spectrometer indicated that the major component of the organics were oxygenated organics which are a marker for aged, photochemically processed aerosol or biomass burning aerosol. The non-refractory aerosol compounds, measured with the Aerosol Mass Spectrometer, contributed between 37 and 50% to the total aerosol mass in the fine mode. A second mass spectrometer for single particle analysis by laser ablation has been used for the first time in the field during this study and yielded results, which agree with filter samples of the coarse particle mode. This mode consisted of sea salt particles and dust aerosol.


2013 ◽  
Vol 40 (6) ◽  
pp. 936-939
Author(s):  
Mei LI ◽  
Jun-Guo DONG ◽  
Zheng-Xu HUANG ◽  
Lei LI ◽  
Wei GAO ◽  
...  

2013 ◽  
Vol 13 (15) ◽  
pp. 7875-7894 ◽  
Author(s):  
I. El Haddad ◽  
B. D'Anna ◽  
B. Temime-Roussel ◽  
M. Nicolas ◽  
A. Boreave ◽  
...  

Abstract. As part of the FORMES summer 2008 experiment, an Aerodyne compact time-of-flight aerosol mass spectrometer (cToF-AMS) was deployed at an urban background site in Marseille to investigate the sources and aging of organic aerosols (OA). France's second largest city and the largest port in the Mediterranean, Marseille, provides a locale that is influenced by significant urban industrialized emissions and an active photochemistry with very high ozone concentrations. Particle mass spectra were analyzed by positive matrix factorization (PMF2) and the results were in very good agreement with previous apportionments obtained using a chemical mass balance (CMB) approach coupled to organic markers and metals (El Haddad et al., 2011a). AMS/PMF2 was able to identify for the first time, to the best of our knowledge, the organic aerosol emitted by industrial processes. Even with significant industries in the region, industrial OA was estimated to contribute only ~ 5% of the total OA mass. Both source apportionment techniques suggest that oxygenated OA (OOA) constitutes the major fraction, contributing ~ 80% of OA mass. A novel approach combining AMS/PMF2 data with 14C measurements was applied to identify and quantify the fossil and non-fossil precursors of this fraction and to explicitly assess the related uncertainties. Results show with high statistical confidence that, despite extensive urban and industrial emissions, OOA is overwhelmingly non-fossil, formed via the oxidation of biogenic precursors, including monoterpenes. AMS/PMF2 results strongly suggest that the variability observed in the OOA chemical composition is mainly driven in our case by the aerosol photochemical age. This paper presents the impact of photochemistry on the increase of OOA oxygenation levels, formation of humic-like substances (HULIS) and the evolution of α-pinene SOA (secondary OA) components.


2017 ◽  
Author(s):  
Carlo Bozzetti ◽  
Imad El Haddad ◽  
Dalia Salameh ◽  
Kaspar Rudolf Daellenbach ◽  
Paola Fermo ◽  
...  

Abstract. We investigated the seasonal trends of OA sources affecting the air quality of Marseille (France) which is the largest harbor of the Mediterranean Sea. This was achieved by measurements of nebulized filter extracts using an aerosol mass spectrometer (offline-AMS). PM2.5 (particulate matter with an aerodynamic diameter


2017 ◽  
Vol 68 (4) ◽  
pp. 873-878
Author(s):  
Alexandru Dandocsi ◽  
Anca Nemuc ◽  
Cristina Marin ◽  
Simona Andrei

An intensive measurement campaign was performed during September 2014 in southern Romania in two different locations: Magurele, Ilfov County and Turceni, Gorj County. This paper presents one case study with analysis of the aerosol properties from in-situ, passive remote sensing and active remote sensing measurements. A Multiwavelength Raman Lidar (RALI) provided one hour averaged vertical profiles of extinction and backscatter from the 532 nm and 1064 nm channels in Magurele. The UV scanning Lidar (MILI) provided one hour averaged backscattered and extinction vertical profiles for Turceni. Planetary Boundary Layer Height (PBLH) was calculated using the altitude of the maximum negative gradient of the range corrected signal. Mass concentrations for different aerosol species (organics, nitrate, sulphate, ammonium and chloride) were obtained from in-situ measurements using Aerosol Mass Spectrometer located in M�gurele and Aerosol Chemical Speciation Monitor (ACSM) located in Turceni.


Sign in / Sign up

Export Citation Format

Share Document