Interstellar ices are widely observed in the infrared spectra of regions where stars and
planetary systems form. Photochemical and thermal evolution of these ices is simulated and
studied in our laboratory where the resulting production of complex organic residues is
routinely performed. Observations of their variability with slightly different starting
chemical conditions can be performed by means of infrared spectroscopy. Organic residues
have interesting chemical properties that make them good potential candidates for
prebiotic chemistry. Numerous other analytical methods (GC-MS, HPLC, mass spectrometry,
etc.) can be combined to refine the knowledge of their chemical composition and structure.
We present here some results on the obtained organic residue resulting from subsequent
heating and sublimation of the irradiated ices which show the formation of some
macromolecular species.