Details

Autor(en) / Beteiligte

• Burton, Aaron S.
• Glavin, Daniel P.
• Elsila, Jamie E.
• Dworkin, Jason P.
• Jenniskens, Peter
• Yin, Qing‐Zhu

Titel

The amino acid composition of the Sutter's Mill CM 2 carbonaceous chondrite

Ist Teil von

• Meteoritics & planetary science, 2014-11, Vol.49 (11), p.2074-2086

Erscheinungsjahr

2014

Link zum Volltext

Quelle

Wiley HSS Collection

Beschreibungen/Notizen

• Abstract We determined the abundances and enantiomeric compositions of amino acids in Sutter's Mill fragment #2 (designated SM 2) recovered prior to heavy rains that fell April 25–26, 2012, and two other meteorite fragments, SM 12 and SM 51, that were recovered postrain. We also determined the abundance, enantiomeric, and isotopic compositions of amino acids in soil from the recovery site of fragment SM 51. The three meteorite stones experienced terrestrial amino acid contamination, as evidenced by the low d/l ratios of several proteinogenic amino acids. The d/l ratios were higher in SM 2 than in SM 12 and SM 51, consistent with rain introducing additional l‐ amino acid contaminants to SM 12 and SM 51. Higher percentages of glycine, β‐alanine, and γ‐amino‐ n ‐butyric acid were observed in free form in SM 2 and SM 51 compared with the soil, suggesting that these free amino acids may be indigenous. Trace levels of d + l‐ β‐aminoisobutyric acid (β‐ AIB ) observed in all three meteorites are not easily explained as terrestrial contamination, as β‐ AIB is rare on Earth and was not detected in the soil. Bulk carbon and nitrogen and isotopic ratios of the SM samples and the soil also indicate terrestrial contamination, as does compound‐specific isotopic analysis of the amino acids in the soil. The amino acid abundances in SM 2, the most pristine SM meteorite analyzed here, are approximately 20‐fold lower than in the Murchison CM 2 carbonaceous chondrite. This may be due to thermal metamorphism in the Sutter's Mill parent body at temperatures greater than observed for other aqueously altered CM 2 meteorites.