Ever wonder....

I like gin tonic. nice strong drink with desirable taste. best of all its glows under the dark UV lights in zouk.

So this baffles me, why does the gin tonic glow in the dark? its a clear liquid under normal lighting, but somehow it glows a nice warm green under UV.

Almost felt like I am drinking a toxic chemical drink.... wait i am drinking a toxic drink.

Anyway, do let me know if any of you knows the answer.