EGU22-9757, updated on 28 Mar 2022
https://doi.org/10.5194/egusphere-egu22-9757
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Solid-phase extraction of aquatic organic matter: loading-dependent chemical fractionation and self-assembly

Xianyu Kong1, Thomas Jendrossek1, Kai-Uwe Ludwichowski1, Ute Marx1, and Boris Koch1,2
Xianyu Kong et al.
  • 1Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany
  • 2University of Applied Sciences, An der Karlstadt 8, 27568 Bremerhaven, Germany

Dissolved organic matter (DOM) is an important component in marine and freshwater environments and plays a fundamental role in global biogeochemical cycles. In the past, optical and molecular-level analytical techniques evolved and improved our mechanistic understanding about DOM fluxes. For most molecular chemical techniques, sample desalting and enrichment is a prerequisite. Solid-phase extraction (SPE) has been widely applied for concentrating and desalting DOM. The major aim of this study was to constrain the influence of sorbent loading on the composition of DOM extracts. Here we show that increased loading resulted in reduced extraction efficiencies of dissolved organic carbon (DOC), fluorescence and absorbance, and polar organic substances. Loading-dependent optical and chemical fractionation induced by altered adsorption characteristics of the sorbent surface (PPL) and increased multilayer adsorption (DOM self-assembly) can fundamentally affect biogeochemical interpretations, such as the source of organic matter. Online fluorescence monitoring of the permeate flow allowed to empirically model the extraction process, and to assess the degree of variability introduced by changing the sorbent loading in the extraction procedure. Our study emphasizes that it is crucial for sample comparison to keep the relative DOC loading (DOCload [wt%]) on the sorbent always similar to avoid chemical fractionation.

How to cite: Kong, X., Jendrossek, T., Ludwichowski, K.-U., Marx, U., and Koch, B.: Solid-phase extraction of aquatic organic matter: loading-dependent chemical fractionation and self-assembly, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-9757, https://doi.org/10.5194/egusphere-egu22-9757, 2022.