Please use this identifier to cite or link to this item:
PIRA download icon_1.1View/Download Full Text
Title: The maximum carbonyl ratio (MCR) as a new index for the structural classification of secondary organic aerosol components
Authors: Zhang, Y
Wang, K
Tong, H 
Huang, RJ
Hoffmann, T
Issue Date: Jul-2021
Source: Rapid communications in mass spectrometry, 31 July 2021, v. 35, no. 14, e9113
Abstract: Rationale: Organic aerosols (OA) account for a large fraction of atmospheric fine particulate matter and thus are affecting climate and public health. Elucidation of the chemical composition of OA is the key for addressing the role of ambient fine particles at the atmosphere–biosphere interface and mass spectrometry is the main method to achieve this goal.
Methods: High-resolution mass spectrometry (HRMS) is on its way to becoming one of the most prominent analytical techniques, also for the analysis of atmospheric aerosols. The combination of high mass resolution and accurate mass determination allows the elemental compositions of numerous compounds to be easily elucidated. Here a new parameter for the improved classification of OA is introduced – the maximum carbonyl ratio (MCR) – which is directly derived from the molecular composition and is particularly suitable for the identification and characterization of secondary organic aerosols (SOA).
Results: The concept is exemplified by the analysis of ambient OA samples from two measurement sites (Hyytiälä, Finland; Beijing, China) and of laboratory-generated SOA based on ultrahigh-performance liquid chromatography (UHPLC) coupled to Orbitrap MS. To interpret the results, MCR–Van Krevelen (VK) diagrams are generated for the different OA samples and the individual compounds are categorized into specific areas in the diagrams. The results show that the MCR index is a valuable parameter for representing atmospheric SOA components in composition and structure-dependent visualization tools such as VK diagrams.
Conclusions: The MCR index is suggested as a tool for a better characterization of the sources and the processing of atmospheric OA components based on HRMS data. Since the MCR contains information on the concentration of highly electrophilic organic compounds in particulate matter (PM) as well as on the concentration of organic (hydro)peroxides, the MCR could be a promising metric for identifying health-related particulate matter parameters by HRMS.
Publisher: John Wiley & Sons
Journal: Rapid communications in mass spectrometry 
ISSN: 0951-4198
EISSN: 1097-0231
DOI: 10.1002/rcm.9113
Rights: © 2021 The Authors. Rapid Communications in Mass Spectrometry published by John Wiley & Sons Ltd. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License (, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.
The following publication Zhang, Y., Wang, K., Tong, H., Huang, R. J., & Hoffmann, T. (2021). The maximum carbonyl ratio (MCR) as a new index for the structural classification of secondary organic aerosol components. Rapid Communications in Mass Spectrometry, 35(14), e9113 is available at
Appears in Collections:Journal/Magazine Article

Files in This Item:
File Description SizeFormat 
rcm.9113.pdf2.04 MBAdobe PDFView/Open
Open Access Information
Status open access
File Version Version of Record
View full-text via PolyU eLinks SFX Query
Show full item record

Page views

Last Week
Last month
Citations as of Jul 7, 2024


Citations as of Jul 7, 2024


Citations as of Jul 11, 2024


Citations as of Jul 11, 2024

Google ScholarTM



Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.