That's how it kinda works out there lol
You have so many vendors just randomly claim USP on Amazon..
The oil GCMS you see is China oil, veg oil + mct + eo. The mct components do match the MIG, but everything else is "extra", some cheap mix.
You can get it tested by finding the MIG specs, then finding a lab to test according to it. I'd say don't bother, spend your money on better equipment etc whatever instead.
E.g
Tested based off USP.
Ph.Eur
If you really want to test something, I'd find one that simply tests for oil oxidation (peroxide) then may do that for every batch. I don't think people care as much as long as it's pure MCT + no oxidation.