Call me silly, but if your lab is using an HPLC to test your sample. They can and do pull out and isolate all of the cannabinoids during the testing.
Seems to me that one single test can be used to determine potency and lay out the cannabinoid/terpene profile. Not sure why the labs charge separately for them unless they use a GC mass spec for one test and the HPLC for the other. Anyone have any insight?