Mass spectrum of ~13.5 nm-thick methanol ice deposited and VUV irradiated at 20 K for 64 min. The sample is heated to 210 K before acquiring the mass spectrum; 70 eV electrons are used as an ionisation source. The experimental results are compared to the NIST fragmentation pattern of glyceraldehyde (HOCH₂CHOHCHO), glycerin (HOCH₂CHOHCH₂OH), and glycolic acid (HOCH₂COOH), for clarity plotted on logarithmic scale.