TPD curves of two mixed-ice experiments, H₂O:H₂S = 9.3:1 (top) and H₂O:¹³CO₂ = 14:1 (bottom). The desorption data of H₂O, H₂S, and ¹³CO₂ are shown in gray (m/z = 18, [H₂O]⁺), red (m/z = 34, [H₂S]⁺), and blue (m/z = 45, [¹³CO₂]⁺), respectively. Two desorption regimes are seen for H₂S: a submonolayer H₂S-H₂O desorption feature and a molecular volcano desorption peak. For ¹³CO₂, a third regime is observed between its submonolayer and volcano peaks, indicating constant sublimation within that temperature range.