Need help making sense of amphetamine analysis on GC/MS

[rhubarb]

Hello all.

I am not a chemist of any kind so my understanding of all of this is extremely basic. Please bear with me.
I have access to a lab where I can run samples on GC/MS. Three different amphetamine samples have yielded almost identical results with a small amphetamine peak and a large caffeine peak. I'm starting to suspect something is off here with regards to the ratios.
For one: based on the peaks, the ratio is always roughly 20/80% amp to caffeine. Ingesting 20mg of such a mixture should yield no effects, yet it does. Acetone washing also does not result in a massive loss.

It does not seem to matter whether the sample is injected as the (presumed) salt, or freebased first. How should I go about testing it again? I have pure anhydrous caffeine as well and I'm thinking this could be used as a calibration reference somehow before I run another sample but I wanted to rule out any other factors, such as certain expected behavior of both compounds under these conditions. Thanks!

 

[G.Patton]

Hello, you have to place a sample into a flask and add there non-polar solvent like DCM or TCM. Then, add there alkiline solution to make free base. Than, remove water layer and inject sample in your injector of GC-MS. Read my post about GC-MS. GC-MS methods for drugs

Salt form may spoil your MS detector and column, do not inject this form.

20/80% amph/caffeine can cause psychoactive effects.

 

[HerrHaber]

The ideal case is when you have standards for both compounds and you apply the internal standard method (so you see the difference in the one with internal standard) and measure the growth of the peak area.