Species identification in QMS-TPD data. Left: desorption signals of interested masses obtained during the TPD experiment after UV irradiation of C₂H₂:NH₃ (1:1.4) for a fluence of 5.7 × 10¹⁷ photon cm⁻² at 10 K. The ion signals have been shifted for clarity. The dashed lines indicate the desorption peak of the assigned molecules. Right: comparison of the obtained mass fragmentation pattern at 136.4, 137.3/137.7, and 155.2 K with standard data for CH₃CN (NIST), CH₂CHNH₂ (Spec-traBase), and CH₃CH₂NH₂ (NIST).