Just want to reference the above post plus....
There are many different spectrometry apparatus out there available. Many, many compounds once attempted to be made cannot be unmade which means once an action happens it cannon be undone.
If I bake a cake I do a pretty decent job however when I see the amazing cakes in the Polish deli say I know I know next to nothing. That person is a professional baker. The root supplier (many of which do not sell to end users) has professionals working for them, in well supplied facilities using respectable QA principals. What good is a one time sale to me if I am a business man? There are chemists or those that know exactly what they are doing at the top of the manufacturing decisions- manufacturing issues equal sales issues. Do you see how the onion layers open?
Finally that comment on QSC product is disturbing to me. Not judging anyone or anything however I will throw this out there- I may be able to obtain raws with tests that I can believe to be true however anything and everything else is subject to consideration
Do you want to see what is really happening with a supplier of finished product? Send it for mass spectrum and hold onto your britches