Journal
RADIATION RESEARCH
Volume 161, Issue 3, Pages 346-358Publisher
RADIATION RESEARCH SOC
DOI: 10.1667/RR3114.1
Keywords
-
Ask authors/readers for more resources
Decomposition of five amino acids, alanine, serine, cysteine, aspartic acid, and asparagine, under irradiation with soft X rays (magnesium K-alpha X-ray source) in ultra-high vacuum was studied by means of X-ray photoelectron spectrometry (XPS) and mass spectrometry. A comparative analysis of changes in XPS line shapes, stoichiometry and residual gas composition indicates that the molecules decompose by several pathways. Dehydration, decarboxylation, decarbonylation, deamination and desulfurization of pristine molecules accompanied by de sorption of H-2, H2O, CO2, CO, NH3 and H2S are observed with rates depending on the specific amino acid. NEXAFS spectra of cysteine at the carbon, oxygen and nitrogen K-shell and sulfur L-2,L-3 edges complement the XPS and mass spectrometry data and show that the exposure of the sample to an intense soft X-ray synchrotron beam results in the formation of C-C and C-N double and triple bonds. Qualitatively, the amino acids studied can be arranged in the following ascending order of radiation stability: serine < alanine < aspartic acid < cysteine < asparagine. (C) 2004 by Radiation Research Society.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available