title: The radiolysis and radioracemization of amino acids on silica surfaces.
abstract: L-Leucine, deposited on both 1-quartz powder and on a commercial amorphous silica preparation (Syloid 63), has been subjected to irradiation in a 60Co gamma-ray source, and the ensuing radiolysis and radioracemization have been determined gas chromatographically. The radiolysis and radioracemization observed for leucine on 1-quartz were rather similar to those noted for a crystalline L-leucine control. L-Leucine on Syloid 63, however, was vastly more susceptible to radiolysis as compared to the L-leucine control, and radioracemization was also markedly enhanced - each increasing with larger radiation dosage. L-Isovaline showed a similar, but diminished, enhancement of radiolysis sensitivity when adsorbed on the Syloid surface, but underwent no radioracemization whatsoever. The divergent results of the control and quartz-leucine irradiations versus the Syloid-leucine and Syloid-isovaline irradiations are interpreted qualitatively in terms of the surface area parameters of the two silica adsorbents and the amino acid adsorbates.
mesh_terms: D000596:Amino Acids / Q000528:radiation effects*; D002849:Chromatography, Gas; D003037:Cobalt Radioisotopes; D007536:Isomerism; D007930:Leucine / Q000528:radiation effects; D011791:Quartz; D012822:Silicon Dioxide; D014633:Valine / Q000528:radiation effects
chemical_list: D000596:Amino Acids; D003037:Cobalt Radioisotopes; D011791:Quartz; C032738:syloid 63; C032737:isovaline; D012822:Silicon Dioxide; D007930:Leucine; D014633:Valine