Degradation of Amino Acids on Mars by UV Irradiation in the Presence of Chloride and Oxychlorine Salts

A potential application for life-related organics detection on Mars by diffuse reflectance infrared spectroscopy

“…3 c) was an exception whose absorption peak intensity increased along with reaction time which might be due to the other newly generated organic matter during CO 2 discharge conditions. On the other hand, we also speculated that the change of sample color would hinder the direct irradiation of CO 2 plasma reaction on amino acid during ESD reaction, and slow down its degradation to a certain extent [ 41 ]. If true, the degradation rate is slower than that of amino acids.…”

“…As reported, the infrared spectra of organic molecules decreases significantly along with reduction of mass and color change by long time of UV radiation, which would ultimately be responsible for the total degradation of the IR signal [ [41] , [42] , [43] ]. Those phenomenons are similar and consistent with our results of organic molecules by ESD reaction.…”

Chemical, Thermal, and Radiation Resistance of an Iron Porphyrin: A Model Study of Biosignature Stability

“…However, in natural environments, often two or more of these factors act together, and their combined effect may differ from the sum of the individual effects. It has been shown, for example, that NaClO 3 and NaClO 4 can either increase or decrease the UV decomposition rate of amino acids, depending on the amino acid and the humidity conditions (Liu and Kounaves, 2021 ). It is conceivable that similar (positive or negative) synergistic effects may occur for [FeCl(oep)].…”

Planning Implications Related to Sterilization-Sensitive Science Investigations Associated with Mars Sample Return (MSR)

“…Although UV-C might be used to sterilize surfaces within the SRF, UV radiation is non-penetrative and therefore ineffective at sterilizing the interior volumes or shaded areas of samples (Kerny and Schuerger, 2011). UV-C radiation could cause the production of oxychlorine species and the subsequent oxidation of amino acids without effectively sterilizing the sample (Liu et al, 2021). Consequently, UV radiation would not be applicable to subsample sterilization.…”