Velencore

I have completed The Distress Signal but upon passing the science check on Vaughn's terminal for the raptidon musk, I wasn't given the quest item and so my objective says "Speak to Vaughn" but whenever I select "I found your experiment" he just says 1 line and the window closes. There is no musk in my quest inventory and The completed Distress Signal indicates that I gave Vaughn his research back. I'm stuck and can not figure out a way to complete The Amateur Alchemist.