> Can I ask what         10-Hydroxy-2-decenoic acid is??? And what it would be used for?

Based on the original query titled "Queen Substance", I assume it's queen
pheromones from a lab.  I hope Tom will correct me if I'm wrong.

Karl Showler put on a fascination drone congregation area demonstration at
Gormanston using "queen substance" to attract drones.  A feather dipped into
the queen substance was attached to the tip of a fly fishing rod and we took a
hike on the golf course in search of DCAs.  I've read about them, but this was
the first time I ever witnessed them.  Amazing stuff!  And the queen substance
is pretty potent stuff too.  One guy who smelled the treated feather had
a drone fly into his nose!  True story.

Aaron Morris - thinking drones get a bum rap!