TY - JOUR
T1 - Aerosol Chemistry Resolved by Mass Spectrometry
T2 - Linking Field Measurements of Cloud Condensation Nuclei Activity to Organic Aerosol Composition
AU - Vogel, Alexander L.
AU - Schneider, Johannes
AU - Müller-Tautges, Christina
AU - Phillips, Gavin J.
AU - Pöhlker, Mira L.
AU - Rose, Diana
AU - Zuth, Christoph
AU - Makkonen, Ulla
AU - Hakola, Hannele
AU - Crowley, John N.
AU - Andreae, Meinrat O.
AU - Pöschl, Ulrich
AU - Hoffmann, Thorsten
N1 - Publisher Copyright:
© 2016 American Chemical Society.
PY - 2016/10/18
Y1 - 2016/10/18
N2 - Aerosol hygroscopic properties were linked to its chemical composition by using complementary online mass spectrometric techniques in a comprehensive chemical characterization study at a rural mountaintop station in central Germany in August 2012. In particular, atmospheric pressure chemical ionization mass spectrometry ((-)APCI-MS) provided measurements of organic acids, organosulfates, and nitrooxy-organosulfates in the particle phase at 1 min time resolution. Offline analysis of filter samples enabled us to determine the molecular composition of signals appearing in the online (-)APCI-MS spectra. Aerosol mass spectrometry (AMS) provided quantitative measurements of total submicrometer organics, nitrate, sulfate, and ammonium. Inorganic sulfate measurements were achieved by semionline ion chromatography and were compared to the AMS total sulfate mass. We found that up to 40% of the total sulfate mass fraction can be covalently bonded to organic molecules. This finding is supported by both on- and offline soft ionization techniques, which confirmed the presence of several organosulfates and nitrooxy-organosulfates in the particle phase. The chemical composition analysis was compared to hygroscopicity measurements derived from a cloud condensation nuclei counter. We observed that the hygroscopicity parameter (κ) that is derived from organic mass fractions determined by AMS measurements may overestimate the observed κ up to 0.2 if a high fraction of sulfate is bonded to organic molecules and little photochemical aging is exhibited.
AB - Aerosol hygroscopic properties were linked to its chemical composition by using complementary online mass spectrometric techniques in a comprehensive chemical characterization study at a rural mountaintop station in central Germany in August 2012. In particular, atmospheric pressure chemical ionization mass spectrometry ((-)APCI-MS) provided measurements of organic acids, organosulfates, and nitrooxy-organosulfates in the particle phase at 1 min time resolution. Offline analysis of filter samples enabled us to determine the molecular composition of signals appearing in the online (-)APCI-MS spectra. Aerosol mass spectrometry (AMS) provided quantitative measurements of total submicrometer organics, nitrate, sulfate, and ammonium. Inorganic sulfate measurements were achieved by semionline ion chromatography and were compared to the AMS total sulfate mass. We found that up to 40% of the total sulfate mass fraction can be covalently bonded to organic molecules. This finding is supported by both on- and offline soft ionization techniques, which confirmed the presence of several organosulfates and nitrooxy-organosulfates in the particle phase. The chemical composition analysis was compared to hygroscopicity measurements derived from a cloud condensation nuclei counter. We observed that the hygroscopicity parameter (κ) that is derived from organic mass fractions determined by AMS measurements may overestimate the observed κ up to 0.2 if a high fraction of sulfate is bonded to organic molecules and little photochemical aging is exhibited.
UR - http://www.scopus.com/inward/record.url?scp=84991787710&partnerID=8YFLogxK
U2 - 10.1021/acs.est.6b01675
DO - 10.1021/acs.est.6b01675
M3 - Article
AN - SCOPUS:84991787710
SN - 0013-936X
VL - 50
SP - 10823
EP - 10832
JO - Environmental Science & Technology
JF - Environmental Science & Technology
IS - 20
ER -