Publication Details |
| Category | Text Publication |
| Reference Category | Journals |
| DOI | 10.1007/s00216-026-06668-y |
Licence  |
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| Title (Primary) | Molecular signatures of electrochemically reduced peatland dissolved organic matter resolved by liquid chromatography Fourier transform ion cyclotron resonance mass spectrometry |
| Author | Mobarak, R.; Simon, C.
; Guth, P.; Knorr, K.-H.; Lau, M.P.; Lechtenfeld, O.J.
|
| Source Titel | Analytical and Bioanalytical Chemistry |
| Year | 2026 |
| Department | EAC |
| Language | englisch |
| Topic | T9 Healthy Planet |
| Data and Software links | https://doi.org/10.48758/ufz.16838 |
| Supplements | Supplement 1 |
| Keywords | Electrochemistry; Electron Transfer; Electrocatalysis; Organic Chemistry; Redox Biology; Environmental Chemistry |
| Abstract | Dissolved organic matter (DOM) plays a central role in peatland
carbon cycling, where anoxic conditions, redox processes, and
thermodynamic factors impact carbon preservation. DOM mediates electron
transfer reactions through quinone-like and other redox-active moieties,
substantially influencing electron and carbon balances. However, the
molecular basis of its electron-accepting and electron-donating
capacities remains poorly resolved. Here, DOM from three peatlands was
subjected to mild, direct electrochemical reduction (DER; − 0.59 V vs.
Ag/AgCl) and analyzed by liquid chromatography coupled to Fourier
transform ion cyclotron resonance mass spectrometry (LC-FT-ICR MS).
Dissolved organic carbon concentrations measured before and after DER
indicated only marginal loss of carbon during reduction. In contrast,
electrochemical reduction induced pronounced decreases in FT-ICR
MS-derived total ion counts across peat samples, reaching up to 30%,
relative to unreduced DOM, while the overall molecular formula space was
largely conserved. Changes in signal intensity were negatively
associated with double bond equivalents (DBE), indicating that more
unsaturated molecular formulas were preferentially affected by DER. In
contrast, DBE–O (DBE minus number of oxygen) and modified aromaticity
index showed weaker relationships with intensity changes, suggesting
that the DBE dependence reflects a broader unsaturation-related response
rather than direct reduction of specific functional groups. Across peat
DOM, we found average changes in DBE between −0.23 and −0.62 that
related to bulk electron-accepting capacity (1000 to 1600 µmol e⁻ (gC)⁻1).
We identified molecular unsaturation rather than polarity or oxygen
content as an important descriptor of DOM redox activity and demonstrate
that direct coupling of LC-FT-ICR MS to batch electrolysis can resolve
molecular patterns associated with bulk redox behavior. |
| Mobarak, R., Simon, C., Guth, P., Knorr, K.-H., Lau, M.P., Lechtenfeld, O.J. (2026): Molecular signatures of electrochemically reduced peatland dissolved organic matter resolved by liquid chromatography Fourier transform ion cyclotron resonance mass spectrometry Anal. Bioanal. Chem. 10.1007/s00216-026-06668-y |
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