Does Quinine glow even after you remove it from a black light?
15 0 teraflop You're asking about the difference between [fluorescence](https://en.wikipedia.org/wiki/Fluorescence) (where a substance absorbs light and *immediately* re-emits it) and [phosphorescence](https://en.wikipedia.org/wiki/Phosphorescence) (where a substance absorbs light, stores the energy, and releases it gradually over time).
According to [the abstract of a paper that I found](http://pubs.rsc.org/en/content/articlelanding/2004/cc/b311667k#!divAbstract), quinine is phosphorescent, but only on very short timescales of a few hundred milliseconds. Sorry, it looks like you're out of luck.
2 0 wfaulk I just tested it with a blacklight and Fever Tree brand tonic water, which definitely has real quinine. There is no apparent residual light.
[Here's the video.](https://youtu.be/keDTw0vQnTw)