RT Journal Article T1 The crucial role of molecular emissions on LIBS differentiation of organic compounds of interest in astrobiology under a Mars simulated atmosphere A1 Delgado-Pérez, Tomás A1 Fortes-Román, Francisco Javier A1 Cabalín-Robles, Luisa María A1 Laserna-Vázquez, José Javier K1 Marte (Planeta) - Atmósfera K1 Espectroscopía de plasma inducido por láser K1 Compuestos orgánicos AB In this work, the influence of Martian atmosphere on the recombination mechanisms in laser-induced plasmas of organic compounds of interest in astrobiology has been closely examined. The proposed LIBS methodology reveals new insights concerning the influence of the surrounding atmosphere on the molecular emission of organics. The presence of nitrogen, even in the short concentration found in the low-pressure Mars environment, influences the plasma chemistry and the formation pathways leading to molecular species. Characteristic atomic and molecular emitters (C, H, C2, CN, NH, OH and CH) were inspected in a set of selected organic compounds considered as meaningful biomarkers. For comparative purposes, LIBS analysis was performed in both low-pressure air and Martian atmospheres. Statistical analysis (linear discriminant analysis; DFA) suggested that satisfactory differentiation among materials was feasible under Martian conditions when molecular emissions are computed in the classification algorithm. Atomic lines (C, H) only contribute a mere ~62% to the discriminating analysis, whereas the percentage of successful discrimination was considerably increased (up to 99%) by the progressive introduction of signals associated to molecular bands into the DFA analysis, thus confirming the major contribution of molecular information to the final sorting performance and the feasibility of discriminating closely related organic compounds by LIBS in the Martian atmosphere. PB Elsevier YR 2022 FD 2022-12-04 LK https://hdl.handle.net/10630/26443 UL https://hdl.handle.net/10630/26443 LA eng NO Delgado, T., Fortes, F. J., Cabalín, L. M., & Laserna, J. J. (2022). The crucial role of molecular emissions on LIBS differentiation of organic compounds of interest in astrobiology under a Mars simulated atmosphere. Spectrochimica Acta Part B: Atomic Spectroscopy, 192, 106413. NO his work was partially supported by Programa Operativo FEDER Andalucía 2014–2020, Consejería de Economía y Conocimiento de la Junta de Andalucía, Reference UMA18-FEDERJA-272 and by Project PID2020-119185GB-I00 from Ministerio de Ciencia e Innovación, Spain. The authors would also like to acknowledge the support of the SIGUE-Mars Research Network, the International Space Science Institute (ISSI) Bern and the International Space Science Institute (ISSI) Beijing. // Funding for open access charge: Universidad de Málaga / CBUA DS RIUMA. Repositorio Institucional de la Universidad de Málaga RD 19 ene 2026