Dong Mingtan, Yang Wei, Hao Jialong, Jia Xiaofei, Yang Ou, Lo Michael K F, Cao Bobo, Hu Sen, Lin Yangting
Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
Anal Chem. 2025 Apr 22;97(15):8258-8267. doi: 10.1021/acs.analchem.4c05804. Epub 2025 Mar 18.
The analysis of extraterrestrial organic matter in samples returned by space missions provides a unique opportunity to study prebiotic chemistry. A comprehensive understanding of the occurrence and composition of organic matter is fundamental to unraveling its origin and evolutionary history. However, the scarcity and complexity of these materials pose considerable analytical challenges. Here, we developed a cross-scale multimodal imaging workflow that integrated mass spectrometry imaging (MSI) and vibrational spectroscopy imaging, including desorption electrospray ionization coupled quadrupole-time-of-flight mass spectrometry (DESI-Q-TOF/MS), time-of-flight secondary ion mass spectrometry (TOF-SIMS), nanoscale secondary ion mass spectrometry (NanoSIMS), focal plane array-Fourier transform infrared spectroscopy (FPA-FTIR), and optical photothermal infrared spectroscopy (O-PTIR). This workflow was applied to the Murchison meteorite, with the objective of establishing spatial associations between mineral phases, molecular composition, functional groups, and isotopic composition on a scale from the millimeter to the submicron. The spatial resolution of DESI has been improved from 100 to 200 to 20 μm, enabling spatial correlation with other imaging techniques. For the first time, the enrichment of organic matter─including CHN, CHO, and CHNO compounds and polycyclic aromatic hydrocarbons (PAHs)─in fine-grained rims (FGRs) surrounding silicate chondrules has been observed. Furthermore, the cross-scale multimodal imaging also reveals differences in organic matter composition between Ca-carbonate and phyllosilicates, as well as spatial heterogeneity within the latter. This workflow provides a new paradigm for studying the complex occurrence and composition of organic matter in various research fields, enhancing our understanding of prebiotic materials in the solar system.
对太空任务带回样本中的外星有机物质进行分析，为研究生命起源前的化学过程提供了独特机会。全面了解有机物质的存在和组成对于揭示其起源和演化历史至关重要。然而，这些物质的稀缺性和复杂性带来了相当大的分析挑战。在此，我们开发了一种跨尺度多模态成像工作流程，该流程整合了质谱成像（MSI）和振动光谱成像，包括解吸电喷雾电离耦合四极杆-飞行时间质谱（DESI-Q-TOF/MS）、飞行时间二次离子质谱（TOF-SIMS）、纳米尺度二次离子质谱（NanoSIMS）、焦平面阵列-傅里叶变换红外光谱（FPA-FTIR）和光热红外光谱（O-PTIR）。此工作流程应用于默奇森陨石，目的是在从毫米到亚微米的尺度上建立矿物相、分子组成、官能团和同位素组成之间的空间关联。DESI的空间分辨率已从100μm提高到200μm再到20μm，从而能够与其他成像技术进行空间关联。首次观察到在硅酸盐球粒周围的细粒边缘（FGRs）中有机物（包括CHN、CHO和CHNO化合物以及多环芳烃（PAHs））的富集。此外，跨尺度多模态成像还揭示了碳酸钙和层状硅酸盐之间有机物组成的差异，以及后者内部的空间异质性。此工作流程为研究各个研究领域中有机物质的复杂存在和组成提供了新范式，增强了我们对太阳系中生命起源前物质的理解。
