A lot of coke cuts are just myths. Speed for example. I had a keen interest for many years in observing coke lab results and in the thousands I have seen, I have only ever noticed ONE with an amphet cut. It just doesn't happen
As someone who works at a lab with GC/MS, HPLC, and now even a polarimeter, this is flat out wrong. Is it as common as people think? Probably not.
If my roommate had only waited a few days for the results of his sample he submitted, he would have known there was methamphetamine in his coke BEFORE violating his probation via a dirty piss test (meth). My roommate does not knowingly do meth, but he loves his cocaine. He always kinda blamed me, but I can't control how quickly these tests get performed. Theres usually a line.
If you really want I could prolly scour past test results and provide them, but in short I'd say out of a few hundred tests over the past 2 years, we've detected some sort of amphetamine I'd say prolly close to 10 times...
What surprises me, I've detected Leviamisole I think only twice in that same time period. There probably was a long chunk of time that leviamisole was in most cocaine in the US. I think that has changed though. From what I can see, the cocaine has gotten purer and purer and purer. It gets stepped on AFTER arriving in the US, whereas before, according to the DEA, they were seizing imported cocaine that already had leviamisole from the source countries. In a lot of these latin american countries, leviamisole is sold on the bus as a dewormer, so there is zero control down there on that substance.
Most tests I run, I see Cocaine, and then benzoyl ecgonidine methyl ester which i believe is likely an artifact due to GC analysis, and usually thats it. Though we commonly detect other cocaine alkaloids (tropacocaine, ecgonidine) in small concentrations, and then the other common caines (procaine, lidocaine primarily). We sometimes see metabolites which probably shouldn't be there (norcocaine) and aren't sure why.
Here was a wild surprise. Once someone gave me 4 samples to test, indicating that one of them was the best. After analytics we found that was actually the lowest purity of the 4 samples, however it contained most of the other natural coca alkaloids that are seen. It was considered warmer, smoother, more euphoric.
EDIT* We commonly see solvents like Decane, or other high boiling point solvents found in gasoline. I would say 99% of the cocaine we've tested, has residual solvents, sometimes totalling multiple % of the entire sample. I believe diethyl ether is the choice solvent (it's highly restricted in these countries) because it evaporates so easily that the end product is cleaner and stronger by weight.