Quinine (present in tonic water) will fluoresce like that in UV light.
As will quite a few other rigid aromatic molecules.
( The Mock TurtIe ™ --- Thinks you are a cunt, on, Mon 1 Jun 2009, 23:11, archived)

I am going to look for a UV light bulb for the toilet.
I can enjoy post-Gin-and-Tonic glow-in-the-dark pisses, and get a sun tan when I'm sitting waiting for the brown water bus that never comes.
( Pope Shax XIII uses Visio for picture editing, does it show?, Mon 1 Jun 2009, 23:14, archived)