Constraints on isomers of dissolved organic matter in aquatic environments: Insights from ion mobility mass spectrometry
Advanced Search
Select up to three search categories and corresponding keywords using the fields to the right. Refer to the Help section for more detailed instructions.

Search our Collections & Repository

For very narrow results

When looking for a specific result

Best used for discovery & interchangable words

Recommended to be used in conjunction with other fields



Document Data
Clear All
Clear All

For additional assistance using the Custom Query please check out our Help Page


Constraints on isomers of dissolved organic matter in aquatic environments: Insights from ion mobility mass spectrometry

Filetype[PDF-20.06 MB]

Select the Download button to view the document
This document is over 5mb in size and cannot be previewed


  • Journal Title:
    Geochimica et Cosmochimica Acta
  • Personal Author:
  • NOAA Program & Office:
  • Description:
    Elucidating the chemical structure of dissolved organic matter (DOM) is key to understanding this large yet enigmatic carbon pool. Over the last two decades much progress has been made in assigning exceptionally accurate molecular formulas of DOM owing to the application of ultrahigh resolution mass spectrometry, but little is known about the number of isomers in each molecular formula, a question essentially related to the total number of organic molecules in DOM. Such information is critical for a further understanding of the formation and long-term stability of refractory DOM in the ocean. In this work, we used ion mobility quadrupole time of flight liquid chromatography tandem mass spectrometry (IM Q-TOF LC/MS/MS) to analyze DOM samples collected in different aquatic environments including south Texas rivers, Gulf of Mexico, and South China Sea. Our data showed that generally less than 23% of all detected DOM formulas, which shared a small fraction of common molecules (ca. 12%) detected by direct-infusion Fourier transform ion cyclotron resonance MS, contained structurally distinct isomers (represented by “isomer clusters”). In addition, isomer diversity, in terms of how different the structures are, decreased with degradation in both natural and incubation samples. Specifically, the number of structurally distinct isomers was lower at river mouth and open ocean than coastal waters, where organic matter tends to be fresher due to high primary production; and with depth in water column, isomer diversity of DOM also decreased. Results from a set of incubation experiments also showed that the percentages of riverine DOM molecules that have multiple isomer clusters decreased with time, suggesting that biodegradation decreases the diversity of molecules from an isomer perspective. Overall, these results suggested that isomers, at least in a certain fraction of DOM, are highly constrained, and that degradation decreases its isomeric diversity.
  • Keywords:
  • Source:
    Geochimica et Cosmochimica Acta, 308, 353-372
  • DOI:
  • ISSN:
  • Format:
  • Publisher:
  • Document Type:
  • Funding:
  • Rights Information:
    Accepted Manuscript
  • Compliance:
  • Main Document Checksum:
  • Download URL:
  • File Type:

Supporting Files

  • No Additional Files
More +

You May Also Like

Checkout today's featured content at

Version 3.26.1