TY - JOUR
T1 - Decreasing the Uncertainty in the Comparison of Molecular Fingerprints of Organic Aerosols with H/D Exchange Mass Spectrometry
AU - Zherebker, Alexander
AU - Babcock, Oliver
AU - Pereira, Diana L.
AU - D’Aronco, Sara
AU - Filippi, Daniele
AU - Soldà, Lidia
AU - Michoud, Vincent
AU - Gratien, Aline
AU - Cirtog, Manuela
AU - Cantrell, Christopher
AU - Formenti, Paola
AU - Giorio, Chiara
N1 - Publisher Copyright:
© 2024 The Authors. Published by American Chemical Society.
PY - 2024/11/19
Y1 - 2024/11/19
N2 - High-resolution mass spectrometry (HRMS) has become an indispensable tool in the characterization of organic aerosols (OA) providing information on air quality, health assessment, climate trends, reactions, and source apportionment. Spectra-derived lists of formulas and their relative abundances are used to compare ambient OA from different sources or to monitor secondary OA formation under controlled laboratory conditions in smog chamber experiments. Various techniques are implemented to visualize common and unique features, series of precursors, and products. The disadvantage of this conventional approach is in associating elemental compositions to specific compounds, while due to several analytical limitations, the structural information remains hidden. We argue that some of the conclusions derived from this data analysis can be misleading. In this study, we applied in-ESI source H/D exchange (HDX), which facilitated enumeration of labile protons in molecules behind elemental compositions of OA. We applied this technique to compare OA from three different locations representing urban, forest, and marine environments and to examine tentative chemical information derived from Kendrick mass defect (KMD) series analysis. Significant discrepancies were found between numbers of labile protons in protogenic functional groups and the stoichiometry of chemical reactions, which are associated with KMD series. Only a portion of chemical pairs matched target stoichiometries, which highlights the existing limitations in environmental applications of conventional formula-based HRMS data interpretation strategies.
AB - High-resolution mass spectrometry (HRMS) has become an indispensable tool in the characterization of organic aerosols (OA) providing information on air quality, health assessment, climate trends, reactions, and source apportionment. Spectra-derived lists of formulas and their relative abundances are used to compare ambient OA from different sources or to monitor secondary OA formation under controlled laboratory conditions in smog chamber experiments. Various techniques are implemented to visualize common and unique features, series of precursors, and products. The disadvantage of this conventional approach is in associating elemental compositions to specific compounds, while due to several analytical limitations, the structural information remains hidden. We argue that some of the conclusions derived from this data analysis can be misleading. In this study, we applied in-ESI source H/D exchange (HDX), which facilitated enumeration of labile protons in molecules behind elemental compositions of OA. We applied this technique to compare OA from three different locations representing urban, forest, and marine environments and to examine tentative chemical information derived from Kendrick mass defect (KMD) series analysis. Significant discrepancies were found between numbers of labile protons in protogenic functional groups and the stoichiometry of chemical reactions, which are associated with KMD series. Only a portion of chemical pairs matched target stoichiometries, which highlights the existing limitations in environmental applications of conventional formula-based HRMS data interpretation strategies.
KW - KMD series
KW - chemical pairs
KW - high-resolution mass spectrometry
KW - isomers
KW - labile protons
KW - nontarget analysis
KW - structural descriptor
UR - http://www.scopus.com/inward/record.url?scp=85209347031&partnerID=8YFLogxK
U2 - 10.1021/acs.est.4c06749
DO - 10.1021/acs.est.4c06749
M3 - Article
C2 - 39514836
AN - SCOPUS:85209347031
SN - 0013-936X
VL - 58
SP - 20468
EP - 20479
JO - Environmental Science and Technology
JF - Environmental Science and Technology
IS - 46
ER -