Recently I was drying an imidazole compound under vacuum. Long story short, the compound apparently has a melting point right around room temperature and a boiling point not too much higher. Some of the compound made its way into the hosing, but didn't APPEAR to make it into the trap (I opened to inspect and take NMR). The system managed to get quite a lot of air in it, and I ended up getting ~20 mL liquid O2 in the trap. So I pumped it off. Afterward, upon looking at the trap, there was quite a lot of bright purple liquid - almost identicial looking to the attached image, but without the solid looking specs. Looked almost fluorescent, but didn't fluoresce under UV light. Really wanted to take a proton NMR but got lazy and ended up cleaning it. Oh well!