Micro‐Raman spectroscopic investigations of graphite in the carbonaceous meteorites Allende, Axtell and Murchison

Larsen, Kai; Nielsen, O. Faurskov

doi:10.1002/jrs.1466

Cited by 12 publications

(7 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Among these parameters, the intensity ratio of I D /I G is used to estimate the crystallite size of graphite that is the parameter of maturity of graphite crystal (e.g., Larsen and Nielsen, 2006). The peak positions and FWHM are used to estimate the degree of disordering etc.…”

Section: Resultsmentioning

confidence: 99%

Raman spectroscopic study of the noble gas carrier Q in the Allende meteorite

et al. 2009

View full text Add to dashboard Cite

We report Raman spectroscopic results of four density-separated fractions of a floating fraction (material similar to HF-HCl residues enriched in heavy noble gases) of the Allende meteorite. The Raman analyses were performed at two laser powers of 0.5 mW and 2-6 mW with the excitation wavelength of 532 nm. The typical Raman spectra of carbon were observed for all the samples, but these carbonaceous materials were very sensitive to the laser power at the analysis. The Raman parameters except for the intensity ratio of D band and G band are similar in all the fractions at the low laser power, but they changed at the high laser power in a different manner, probably due to the different degree of laserinduced heating. Our findings are that phase Q (the carrier of noble gas of the normal isotopic composition in meteorites) is enriched in the graphitic carbon having larger domain size compared to the major carbon in Allende and that this carbon is most affected by the laser heating.

show abstract

Section: Resultsmentioning

confidence: 99%

Raman spectroscopic study of the noble gas carrier Q in the Allende meteorite

et al. 2009

View full text Add to dashboard Cite

show abstract

“…The selection of this meteorite was because the Raman measurements of Allende have been well studied in many laboratories. [5,6,9,11,13] A fragment of the Allende meteorite was dissolved with HF-HCl to remove silicates, yielding a HF-HCl residue that mainly contains disordered graphitic carbon. We also used CS 2 to remove elemental sulfur during the chemical treatment.…”

Section: Methodsmentioning

confidence: 99%

“…[5,6,11] We speculate that these variations are due to the differences of experimental parameters: conditions and procedures of experiments. The Raman spectrum properties are affected by varying parameters such as laser excitation wavelength, [12,13] acquisition time, room temperature, and the laser power on the sample. [11,[14][15][16] These experimental parameters must be carefully considered when experiments with high precision are carried out.…”

Section: Introductionmentioning

confidence: 99%

On the Effect of Laser-Induced Heating in a Raman Spectroscopic Study of Carbonaceous Material in Meteorite

Morishita

Nara

Amari

et al. 2011

Spectroscopy Letters

View full text Add to dashboard Cite

We examined the dependence of Raman spectroscopic parameters on the laser power for the carbonaceous matter extracted from the Allende meteorite. The Raman parameters, except for the intensity ratios, were linearly correlated with the laser power, suggesting that laser-induced heat affected the sample and that carbonaceous material in meteorite was very sensitive. Our Raman data show that the carbonaceous matter changes into a more amorphous state by the laser-induced heating. Meanwhile, we can define hypothetical parameter values at 0 mW laser power from linear regression so that data from different laboratories can be compared without the effect of laser heating.

show abstract

“…The source composition was normalized (%) to the sum of the 26 PAHs selected. The intensity of automobile Diesel EURO I profile was two orders of magnitude highly sensitive optical analysis technique useful to study atomic microstructures in carbonaceous materials and is sensible to the structural change or rearrangement of carbon crystallites (10). The band attribution of the carbonaceous materials is reported elsewhere (11-16).…”

Section: Micro-raman Spectroscopy and Particles Countmentioning

confidence: 96%

Physicochemical Characterization of Exhaust Particulates from Gasoline and Diesel Engines by Solid-Phase Micro Extraction Sampling and Combined Raman Microspectroscopic/Fast Gas-Chromotography Mass Spectrometry Analysis

et al. 2009

View full text Add to dashboard Cite

Ambient Particulate Matter (PM) has been shown to be associated with cardiopulmonary diseases and lung cancer. Several groups of investigators have shown that the size of the airborne particles and their surface area determine the potential to elicit inflammatory injury and other mechanisms of adverse cellular effects. Because traffic is an important source of PM, it seems obvious that physicochemical characterization of vehicles exhaust emission has an important impact on both quantitative and qualitative aspects of ambient PM. In the present study the exhaust emissions of 8 vehicles of different categories were analyzed to attempt to differentiate them. For such purpose the particulate was collected on SPME fibers exposed to the exhaust emission for 150 s. The particulate was first characterized by micro-Raman spectroscopy and then subjected to Fast Gas Chromatography-Mass Spectrometry analyses for the chemical identification of the Polycyclic Aromatic Hydrocarbons (PAHs) compounds, the organic fraction of particulate matter in air pollution with a major role in the toxicity, notably via its effects on inflammation. Both the particle count and the PAHs compositional data were assembled to be interpreted by Principal Components Analysis. This multivariate analysis grouped the data according mainly to the naphthalene amount, as well as the volume concentration of the particles smaller than 0.5 μm, suggesting that the different exhaust emissions could be easily differentiated. With this new methodology, future research should aim at establishing a mechanism of formation during internal engine combustion processes in order to obtain a clearer picture of the inflammatory and carcinogenic mechanisms of PM in the lungs.

show abstract

Micro‐Raman spectroscopic investigations of graphite in the carbonaceous meteorites Allende, Axtell and Murchison

Cited by 12 publications

References 18 publications

Raman spectroscopic study of the noble gas carrier Q in the Allende meteorite

Raman spectroscopic study of the noble gas carrier Q in the Allende meteorite

On the Effect of Laser-Induced Heating in a Raman Spectroscopic Study of Carbonaceous Material in Meteorite

Physicochemical Characterization of Exhaust Particulates from Gasoline and Diesel Engines by Solid-Phase Micro Extraction Sampling and Combined Raman Microspectroscopic/Fast Gas-Chromotography Mass Spectrometry Analysis

Contact Info

Product

Resources

About