Investigating Amino Acid Heterogeneity in Milligram-Scale Samples of the Murchison CM2 Carbonaceous Chondrite
Analyses of different aliquots of the Tagish Lake meteorite have resulted in amino acid abundance variations of an order of magnitude or more, even when performed using the same techniques, by the same personnel, in the same laboratories (e.g., Simkus et al. 2019). Up to ~five-fold variations have been observed for specific amino acids in different samples of the same meteorite, such as α aminoisobutryic acid (AIB) in Murchison. These variations are often attributed differing sample composition or differing alteration history, neither of which is mutually exclusive. Distinguishing between these two explanations is challenging and time consuming, requiring detailed mineralogical analyses to be performed in conjunction with high precision organics analysis. The potential for innate sample-level heterogeneity presents a significant complication when parsing the effects of different processes or conditions during preparation of meteorite samples for analysis, as differences in organic yields or abundances could be due to differences in laboratory processing or differences among the samples themselves. In this work, we investigated the degree of innate organic heterogeneity present in a single ~250 mg chip of divided into 21 samples.