In-situ Measurements of the Radiation Stability of Amino Acids at 15-140 K

We present new kinetics data on the radiolytic destruction of amino acids measured in situ with infrared spectroscopy.

Samples were irradiated at 15, 100, and 140 K with 0.8-MeV protons, and amino-acid decay was followed at each temperature with and without H2O present. Observed radiation products included CO2 and amines, consistent with amino-acid decarboxylation. The half-lives of glycine, alanine, and phenylalanine were estimated for various extraterrestrial environments. Infrared spectral changes demonstrated the conversion from the non-zwitterion structure NH2-CH2(R)-COOH at 15 K to the zwitterion structure +NH3-CH2(R)-COO at 140 K for each amino acid studied.

P. A. Gerakines, R. L. Hudson, M. H. Moore, J.-L. Bell (Submitted on 9 Feb 2015)

Comments: 35 pages, 7 tables, 11 figures

Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Earth and Planetary Astrophysics (astro-ph.EP) J ournal reference: 2012, Icarus 220, 647-659

DOI: 10.1016/j.icarus.2012.06.001

Cite as: arXiv:1502.02721 [astro-ph.IM] (or arXiv:1502.02721v1 [astro-ph.IM] for this version)

Submission history From: Perry Gerakines [view email] [v1] Mon, 9 Feb 2015 23:03:10 GMT (1840kb) http://arxiv.org/abs/1502.02721