Understanding atmospheric aerosol particles with improved particle identification and quantification by single-particle mass spectrometry

• Verfasst von: Shen, Xiaoli [VerfasserIn]
• Verfasst von: Saathoff, Harald [VerfasserIn]
• Verfasst von: Huang, Wei [VerfasserIn]
• Verfasst von: Mohr, Claudia [VerfasserIn]
• Verfasst von: Ramisetty, Ramakrishna [VerfasserIn]
• Verfasst von: Leisner, Thomas [VerfasserIn]
• Titel: Understanding atmospheric aerosol particles with improved particle identification and quantification by single-particle mass spectrometry
• Verf.angabe: Xiaoli Shen, Harald Saathoff, Wei Huang, Claudia Mohr, Ramakrishna Ramisetty, and Thomas Leisner
• E-Jahr: 2019
• Jahr: 10 Apr 2019
• Umfang: 22 S.
• Fussnoten: Gesehen am 21.08.2019
• Titel Quelle: Enthalten in: Atmospheric measurement techniques
• Ort Quelle: Katlenburg-Lindau : Copernicus, 2008
• Jahr Quelle: 2019
• Band/Heft Quelle: 12(2019), 4, Seite 2219-2240
• ISSN Quelle: 1867-8548
• DOI: doi:10.5194/amt-12-2219-2019
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1671768663

Abstract

<p><strong>Abstract.</strong> Single-particle mass spectrometry (SPMS) is a widely used tool to determine chemical composition and mixing state of aerosol particles in the atmosphere. During a 6-week field campaign in summer 2016 at a rural site in the upper Rhine valley, near the city of Karlsruhe in southwest Germany, <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M1" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>∼</mo><mn mathvariant="normal">3.7</mn><mo>×</mo><msup><mn mathvariant="normal">10</mn><mn mathvariant="normal">5</mn></msup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="55pt" height="13pt" class="svg-formula" dspmath="mathimg" md5hash="ecd9c994d0009e01f99b4b07902c042e"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="amt-12-2219-2019-ie00001.svg" width="55pt" height="13pt" src="amt-12-2219-2019-ie00001.png"/></svg:svg></span></span> single particles were analysed using a laser ablation aerosol particle time-of-flight mass spectrometer (LAAPTOF). Combining fuzzy classification, marker peaks, typical peak ratios, and laboratory-based reference spectra, seven major particle classes were identified. With the precise particle identification and well-characterized laboratory-derived overall detection efficiency (ODE) for this instrument, particle similarity can be transferred into corrected number and mass fractions without the need of a reference instrument in the field. Considering the entire measurement period, aged-biomass-burning and soil-dust-like particles dominated the particle number (45.0&thinsp;% number fraction) and mass (31.8&thinsp;% mass fraction); sodium-salt-like particles were the second lowest in number (3.4&thinsp;%) but the second dominating class in terms of particle mass (30.1&thinsp;%). This difference demonstrates the crucial role of particle number counts' correction for mass quantification using SPMS data. Using corrections for size-resolved and chemically resolved ODE, the total mass of the particles measured by LAAPTOF accounts for 23&thinsp;%-68&thinsp;% of the total mass measured by an aerosol mass spectrometer (AMS) depending on the measurement periods. These two mass spectrometers show a good correlation (Pearson's correlation coefficient <span class="inline-formula"><i>γ</i>>0.6</span>) regarding total mass for more than 85&thinsp;% of the measurement time, indicating non-refractory species measured by AMS may originate from particles consisting of internally mixed non-refractory and refractory components. In addition, specific relationships of LAAPTOF ion intensities and AMS mass concentrations for non-refractory compounds were found for specific measurement periods, especially for the fraction of org&thinsp;<span class="inline-formula">∕</span>&thinsp;(org&thinsp;<span class="inline-formula">+</span>&thinsp;nitrate). Furthermore, our approach allows the non-refractory compounds measured by AMS to be assigned to different particle classes. Overall AMS nitrate mainly arose from sodium-salt-like particles, while aged-biomass-burning particles were dominant during events with high organic aerosol particle concentrations.</p>