气候变化领域集成服务门户(CCPortal): New preparation techniques for molecular and in-situ analysis of ancient organic micro- and nanostructures

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DOI	10.1111/gbi.12380
	New preparation techniques for molecular and in-situ analysis of ancient organic micro- and nanostructures
	Fadel A.; Lepot K.; Nuns N.; Regnier S.; Riboulleau A.
发表日期	2020
ISSN	14724677
起始页码	445
结束页码	461
卷号	18 期号:4
英文摘要	Organic microfossils preserved in three dimensions in transparent mineral matrices such as cherts/quartzites, phosphates, or carbonates are best studied in petrographic thin sections. Moreover, microscale mass spectrometry techniques commonly require flat, polished surfaces to minimize analytical bias. However, contamination by epoxy resin in traditional petrographic sections is problematic for the geochemical study of the kerogen in these microfossils and more generally for the in situ analysis of fossil organic matter. Here, we show that epoxy contamination has a molecular signature that is difficult to distinguish from kerogen with time-of-flight secondary ion mass spectrometry (ToF-SIMS). This contamination appears pervasive in organic microstructures embedded in micro- to nano-crystalline carbonate. To solve this problem, a new semi-thin section preparation protocol without resin medium was developed for micro- to nanoscale in situ investigation of insoluble organic matter. We show that these sections are suited for microscopic observation of Proterozoic microfossils in cherts. ToF-SIMS reveals that these sections are free of pollution after final removal of a <10 nm layer of contamination using low-dose ion sputtering. ToF-SIMS maps of fragments from aliphatic and aromatic molecules and organic sulfur are correlated with the spatial distribution of organic microlaminae in a Jurassic stromatolite. Hydrocarbon-derived ions also appeared correlated with kerogenous microstructures in Archean cherts. These developments in analytical procedures should help future investigations of organic matter and in particular, microfossils, by allowing the spatial correlation of microscopy, spectroscopy, precise isotopic microanalyses, and novel molecular microanalyses such as ToF-SIMS. © 2020 John Wiley & Sons Ltd
关键词	Archean detection method in situ measurement Jurassic kerogen microfossil molecular analysis organic matter Proterozoic spatial distribution stromatolite
语种	英语
来源机构	Geobiology
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/133183
推荐引用方式 GB/T 7714	Fadel A.,Lepot K.,Nuns N.,et al. New preparation techniques for molecular and in-situ analysis of ancient organic micro- and nanostructures[J]. Geobiology,2020,18(4).
APA	Fadel A.,Lepot K.,Nuns N.,Regnier S.,&Riboulleau A..(2020).New preparation techniques for molecular and in-situ analysis of ancient organic micro- and nanostructures.,18(4).
MLA	Fadel A.,et al."New preparation techniques for molecular and in-situ analysis of ancient organic micro- and nanostructures".18.4(2020).