Formula-level comparison of Murchison and Aguas Zarcas SOM based on merged monoisotopic molecular formula assignments from the sequential extracts. Venn diagrams show formulas detected only in Murchison, only in Aguas Zarcas, and shared by both meteorites for (+) ESI and (−) ESI. Corresponding van Krevelen diagrams show the H/C and O/C distributions for each formula group, with heteroatom classes indicated by color. Unique formulas refer to formulas detected only in one meteorite under the present extraction, ionization, and assignment workflow, and should not be interpreted as definitive absence from the other sample.