![Schematic representation of the chemical concept explored in this work. (A) Ethanolamine (EtA, NH2CH2CH2OH), methanol (CH3OH), and water (H2O) are subjected to electron irradiation, illustrating the starting molecular components and the formation of an unresolved product inventory after energetic processing. The question mark denotes the chemically diverse products investigated by FTIR, TPD-QMS, and ESI-MS. (B) Structure of the choline cation, [(CH3)3NCH2CH2OH]+ , included as a structurally related reference for assessing methylated EtA-derived and/or choline-like spectral features. -- [astro-ph.GA]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/09/Electron.png?fit=1200%2C675&ssl=1)
[astro-ph.GA]. Ethanolamine (EtA) is a recently detected interstellar complex organic molecule and a potential precursor to more functionalised N-bearing species.
We investigate the electron-driven chemistry of layered EtA–H2O–CH3OH ices deposited at 20K, combining 2keV electron irradiation with subsequent temperature-programmed desorption (TPD) while monitoring the solid phase by mid-infrared spectroscopy. These controlled irradiation conditions represent a simplified laboratory analogue of the structural and energetic conditions within interstellar grain mantles.
Volatile products released during warming were followed by quadrupole mass spectrometry, and the final residue was analysed by ex situ electrospray ionisation mass spectrometry (ESI-MS). Irradiation produces abundant radiolysis products typical of processed methanol- and water-rich ices, including CO, CO2, H2CO, H2O2, NH3, and OCN−.
Bands consistent with formic acid and polyoxymethylene-like material are also observed, indicating that carbonyl chemistry and formaldehyde-driven oligomerisation can occur alongside fragmentation in the layered system. Comparison with a choline chloride–H2O reference reveals the emergence of features compatible with methylated EtA derivatives and/or choline-like species, while ESI-MS shows higher-m/z mass families in the residue that are not reproduced in the substrate/background blank.
However, spectral congestion and matrix effects preclude an unambiguous assignment of choline. Our results show that energetic processing of EtA-containing ices can generate a diverse inventory of O- and N-bearing products, providing laboratory constraints on radiation chemistry in cold, irradiated grain mantles under idealised conditions.
Tara L. Stoib, Alejandro Guerrero-Caicedo, Duncan V. Mifsud, Péter Herczku, Gergő Lakatos, Zuzana Kaňuchová, Zoltán Juhász, Béla Sulik, Nigel J. Mason, Sergio Ioppolo, Paola Caselli, Barbara Michela Giuliano, Karl E. Duderstadt, Felipe Fantuzzi, Heidy M. Quitián-Lara
Comments: 16 pages, 9 figures, 5 tables. Accepted for publication in MNRAS
Subjects: Astrophysics of Galaxies (astro-ph.GA)
Cite as: arXiv:2609.20111 [astro-ph.GA] (or arXiv:2609.20111v1 [astro-ph.GA] for this version)
https://doi.org/10.48550/arXiv.2609.20111
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Submission history
From: Heidy M Quitian-Lara
[v1] Thu, 17 Sep 2026 12:10:09 UTC (3,021 KB)
https://arxiv.org/abs/2609.20111
Astrobiology, Astrochemistry,
