Thermal desorption of a mixed H₂O:CO₂:CO ice film at 100:15:5 ratio recorded during a Temperature Programmed Desorption (TPD) experiment, where the release of each molecule is measured with a mass spectrometer. Carbon monoxide was traced with the ¹³CO isotope. Four distinct release events are visible: pure-phase CO (1), pure-phase CO₂ with CO co-desorbing (2), volcano desorption of CO and CO₂ (3), and water desorption with co-desorption of CO and CO₂ (4). Desorption and trapping fractions of volatiles can be determined by integrating the TPD trace over discrete temperature ranges. The data are adapted from Kipfer et al. (2024a).