Searching for organic compounds in the Universe

International audienceSearching for signs of past or present life in our Solar System is a major challenge for the space-research community. One approach involves searching for organics. However, it encompasses major challenges, such as their very low concentration levels, their ambiguous origins (biotic or abiotic) and their supposed diversity and complexity. Even if, during the past 40 years, tremendous improvements in sample treatment, stationary phase and mass spectrometry detection have been achieved, there is still a need for new in-situ scientific instrumentation. The objective of this article is to give a broad canvas of instrumentation and technology available to space-survey missions and those further out. It is also a critical review where we discuss analytical science questions, and the technology needed to address the

Simple Derivatization–Gas Chromatography–Mass Spectrometry for Fatty Acids Profiling in Soil Dissolved Organic Matter

Dissolved organic matter is an important component of the global carbon cycle that allows the distribution of carbon and nutrients. Therefore, analysis of soil dissolved organic matter helps us to better understand climate change impacts as it is the most dynamic and reactive fraction in terrestrial ecosystems. Its characterization at the molecular level is still challenging due to complex mixtures of hundreds of compounds at low concentration levels in percolating water. This work presents simple methods, such as thermochemolysis– or derivatization–gas chromatography, as an alternative for the analysis of fatty acids in dissolved organic matter without any purification step. The variables of the protocols were examined to optimize the processing conditions for the C9–C18 range. As a proof of concept, fatty acid distributions of soil percolating water samples from a long-term field experiment were successfully assessed. The variability of dissolved organic acid distributions was pronounced through depth profile and soil treatment but no major change in composition was observed. However, although the optimization was done from C9 to C18, detection within the C6-C32 fatty acids range was performed for all samples

Data for dynamics analysis of soil dissolved organic matter. Long term amendment effect

International audienceThe data presented here are related to the research paper entitled “Spectral characteristics of soil dissolved organic matter: long-term effects of exogenous organic matter on soil organic matter and spatial-temporal changes” (Musadji et al., 2020). Fluorescence Excitation-Emission Matrixes and DOC content of 39 suction cup soil solutions are given for a control and an urban green waste compost amended soil sampled in spring and autumn. Principal component analysis (PCA) was used to identify possible spatial-temporal trends and to emphasize the long term effect of organic amendment on soil organic matter quality

Speciation of trace metals in organic matter of contaminated urban sediments

A methodology based on the coupling of chemical methods (methyl isobu-tyl ketone (MIBK) and IHSS fractionations) and physical characterization methods (XRD and SEM) was applied to study the relevance of these two fractionation methods on the speciation of trace metals in organic matter of three stormwater sediments. Trace metals distribution among MIBK and IHSS fractions is very different. Except for Cr, 10 to 30% of trace metals are bonded to MIBK-humin fractions, whereas 70 to 100% are bonded to IHSS-humin fraction. Moreover, Cd, Cr, Ni and Zn are strongly bonded to the highly aggregated fraction

Gas Chromatography Fingerprint of Martian Amino Acids before Analysis of Return Samples

Within the perspective of the current and future space missions, the detection and separation of building blocks such as amino acids are important subjects which are becoming fundamental in the search for the origin of life and traces of life in the solar system. In this work, we have developed and optimized a strategy adapted to space experimentation to detect the presence of amino acid-like compounds using gas chromatography coupled to mass spectrometry (GC-MS). Selected derivatization methods meet the instrument design constraints imposed on in situ extraterrestrial experiments. Coupled to a fast selective extraction, GC analysis would be highly efficient for the detection of organic materials. In the future, the corresponding GC-MS TIC could facilitate simple and fast selection of sediments/dust samples onboard GC-MS-equipped rovers for sample return-to-Earth missions

TCA precipitation and ethanol/HCl single-step purification evaluation: One-dimensional gel electrophoresis, bradford assays, spectrofluorometry and Raman spectroscopy data on HSA, Rnase, lysozyme - Mascots and Skyline data

The data presented here are related to the research paper entitled “Study of a Novel Agent for TCA Precipitated Proteins Washing - Comprehensive Insights into the Role of Ethanol/HCl on Molten Globule State by Multi-Spectroscopic Analyses” (Eddhif et al., submitted for publication) [1]. The suitability of ethanol/HCl for the washing of TCA-precipitated proteins was first investigated on standard solution of HSA, cellulase, ribonuclease and lysozyme. Recoveries were assessed by one-dimensional gel electrophoresis, Bradford assays and UPLC-HRMS. The mechanistic that triggers protein conformational changes at each purification stage was then investigated by Raman spectroscopy and spectrofluorometry. Finally, the efficiency of the method was evaluated on three different complex samples (mouse liver, river biofilm, loamy soil surface). Proteins profiling was assessed by gel electrophoresis and by UPLC-HRMS

Distribution of PAHs and trace metals in urban stormwater sediments: combination of density fractionation, mineralogy and microanalysis

International audienceSediment management from stormwater infiltration basins represents a real environmental and economic issue for stakeholders due to the pollution load and important tonnages of these by-products. To reduce the sediment volumes to treat, organic and metal micropollutant-bearing phases should be identified. A combination of density fractionation procedure and microanalysis techniques was used to evaluate the distribution of polycyclic aromatic hydrocarbons (PAHs) and trace metals (Cd, Cr, Cu, Ni, Pb, and Zn) within variable density fractions for three urban stormwater basin sediments. The results confirm that PAHs are found in the lightest fractions (d 2.8 g cm(-3)) and are mostly in the 2.3 < d < 2.6 g cm(-3) fraction. The characterization of the five fractions by global analyses and microanalysis techniques (XRD and MEB-EDX) allowed us to identify pollutant-bearing phases. PAHs are bound to the organic matter (OM) and trace metals to OM, clays, carbonates and dense particles. Moreover, the microanalysis study underlines that OM is the main constituent responsible for the aggregation, particularly for microaggregation. In terms of sediment management, it was shown that density fractionation is not suitable for trace metals but could be adapted to separate PAH-enriched phases

Focused ultrasound extraction versus microwave-assisted extraction for extraterrestrial objects analysis

International audienc

Study of a novel agent for TCA precipitated proteins washing - comprehensive insights into the role of ethanol/HCl on molten globule state by multi-spectroscopic analyses

International audienc

Primary Step Towards In Situ Detection of Chemical Biomarkers in the UNIVERSE via Liquid-Based Analytical System: Development of an Automated Online Trapping/Liquid Chromatography System

The search for biomarkers in our solar system is a fundamental challenge for the space research community. It encompasses major difficulties linked to their very low concentration levels, their ambiguous origins (biotic or abiotic), as well as their diversity and complexity. Even if, in 40 years&#8217; time, great improvements in sample pre-treatment, chromatographic separation and mass spectrometry detection have been achieved, there is still a need for new in situ scientific instrumentation. This work presents an original liquid chromatographic system with a trapping unit dedicated to the one-pot detection of a large set of non-volatile extra-terrestrial compounds. It is composed of two units, monitored by a single pump. The first unit is an online trapping unit able to trap polar, apolar, monomeric and polymeric organics. The second unit is an online analytical unit with a high-resolution Q-Orbitrap mass spectrometer. The designed single pump system was as efficient as a laboratory dual-trap LC system for the analysis of amino acids, nucleobases and oligopeptides. The overall setup significantly improves sensitivity, providing limits of detection ranging from ppb to ppt levels, thus meeting with in situ enquiries