Fig. 2.

Gas chromatogram showing the diamino acid 3,3′-diaminoisobutanoic acid identified in a sample of the Murchison meteorite (Mur). Data were obtained after hot-water extraction, 6 M HCl hydrolysis, and ECEE derivatization by application of the standard GC-MS protocol. Detection was in the single-ion monitoring mode of mass trace 142 amu in deviation from Fig. 1. For comparison, the chromatogram of a sample produced experimentally by photoprocessing of circumstellar ice analogues was used as external standard (Std) in the extract ion mode at m/z = 142. The blank sample chromatogram (Blk) was obtained from a serpentine sample analyzed in the single-ion monitoring mode of mass trace 142 amu.