Rapid contamination during storage of carbonaceous chondrites prepared for micro FTIR measurements

Abstract

Abstract-Organic contamination (~2965 and ~1260 cm −1 peaks) was found on Tagish Lake (C2) and Murchison (CM2) carbonaceous chondrites containing abundant hydrous minerals by Fourier transform infrared (FTIR) microspectroscopy on the samples pressed on Al plates. On the other hand, anhydrous chondrite (Moss, CO3) was not contaminated. This contamination occurred within one day of storage, when the samples pressed on Al were stored within containers including silicone rubber mats. Volatile molecules having similar peaks to the contaminants were detected by long-path gas cell FTIR measurements for the silicone rubber mat. Rapid adsorption of the volatile contaminants also occurred when silica gel and hydrous minerals such as serpentine were stored in containers including silicone rubber, silicone grease, or adhesive tape. However, they did not show any contamination when stored in glass and polystyrene containers without these compounds. Therefore, precious astronomical samples such as meteorites, interplanetary dust particles (IDPs), and mission-returned samples from comets, asteroids, and Mars, should be measured by micro FTIR within one day of storage in glass containers without silicone rubber, silicone grease, or adhesive tape.

Enhanced Two‐Photon‐Pumped Emission from In Situ Synthesized Nonblinking CsPbBr3/SiO2 Nanocrystals with Excellent Stability

“…To alter the hydrophilicity of the NCs, 2-methoxyethanol was used as a ligand to modify the surface. [25,29,30] To verify the water solubility and stability of the pure perovskite and perovskite/SiO 2 structures, a solvent containing www.advopticalmat.de toluene and water (ratio 4:1) was used to disperse CsPbBr 3 QDs and CsPbBr 3 /SiO 2 NCs, respectively. The hydrophilic terminal OH functional group of 2-methoxyethanol can bind with silica precursors, heightening the hydrophilicity of CsPbBr 3 /SiO 2 NCs.…”

Compositional diversity in insoluble organic matter in type 1, 2 and 3 chondrites as detected by infrared spectroscopy

“…Background spectra were acquired thorough the BaF 2 disc adjacent to the sample section. The microtome sections are prepared just prior to analysis, in order to avoid any surface contamination that may be adsorbed onto the sample surfaces (Kebukawa et al, 2009). It is noted here that, unlike solid state 13 C nuclear magnetic resonance (NMR) spectroscopy, with vibrational spectroscopy (e.g., FTIR and Raman) it is difficult, if not impossible, to quantitatively determine organic functional group concentrations.…”

Associations of organic matter with minerals in Tagish Lake meteorite via high spatial resolution synchrotron‐based FTIR microspectroscopy

“…Phyllosilicate‐rich carbonaceous chondrites can be especially contaminated in very short times when placed close to silicone rubber, grease, or adhesive tapes as phyllosilicates quickly and efficiently absorb the volatile organics within these materials (Kebukawa et al. ). Clear evidence of silicone contamination is a sharp infrared feature at 1261 cm −1 due to Si‐CH 3 in the spectra of meteorites (e.g., Kebukawa et al.…”

“…Clear evidence of silicone contamination is a sharp infrared feature at 1261 cm −1 due to Si‐CH 3 in the spectra of meteorites (e.g., Kebukawa et al. ). These contaminants result in stronger aliphatic CH bands near 3000–2800 cm −1 .…”