Yes, I concur with Blowen completely.
Yes, there is a way to tell if its synthetic but labs are bound down by regulations and protocols which dictate what they can test for and what not. Labs (US) are only allowed to test for drug metabolites and check the Ph, specific gravity, creatnine and excessive nitrites. As long as the batch of QF is fresh and not exposed to direct sunlight, it will pass these integrity checks. If the batch is old or had been exposed to direct sunlight, the components break down, sending up a red flag with the lab tech.

I periodically home test my two batches of QF to ensure that they are ready for the lab nazis. The tests I use are Drug Adulteration test strips (same type used by the lab nazis) that I've ordered on www.meditests.com
So far, everything is still good to go