Mid-infrared study of the molecular structure variability of insoluble organic matter from primitive chondrites

► We present IR spectra of Insoluble Organic Matter (IOM) extracted from 14 meteorites. ► Our technological breakthrough grants access to very small sample masses. ► We describe a variability of the structure and chemistry of IOM. ► We show that asteroidal thermal processes are efficient at modifying the IOM. ► Aqueous alteration had no significant impact on the molecular structure.