The Sample Analysis at Mars (SAM) instrument onboard NASA Curiosity rover revealed organic matter indigenous to a Martian sample with the detection of chlorohydrocarbons [1]. These molecules are thought to originate from a reaction of unidentified higher molecular mass organic matter with Martian perchlorates. The reaction may occur at Mars’ near-surface induced by the harsh radiative environment, e.g. direct radiation (UV, high energy X- and γ-rays) and secondary photons produced by the interaction of direct radiations with the martian regolith (low energy secondary X-rays). To address the influence of high energy X-rays directly reaching Mars surface on the degradation of organic molecules, a synchrotron session was undertaken on the PSICHE beam line. The reactivity and chemical characterization of L-alanine and benzoic acid exposed to hard X-rays (25-50 keV) did not show any degradation of organics nor formation of chlorohydrocarbons. In conclusion, the X-rays of the PSICHE beam line may have been too energetic for degrading efficiently organic molecules [3, 4]. This why we have investigate the impact of soft X-ray irradiation on the LUCIA beam line at SOLEIL at the 2.6 kv energy which is the energy range for the majority of secondary emissions and monitoring the evolution of perchlorate Cl by X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS).