Charoite said:
That's somewhat of a relief. I'm no chemist so I'm having trouble understanding...
When mixing an acidic vinegar solution with the NPS in question it causes an unknown "salt?" to appear in the vinegar, however when the NPS that has not been in contact with an acid is evaporated it leaves no residue.
It was mentioned in a previous comment that the re-x left no trace of contamination.
Is it logical to presume that the unknown contaminant remains in the NPS after freeze precipitation or does it somehow combine with the DMT suspended in the NPS causing a contaminated product when it crashes out?
Sounds like you have a pretty good understanding. And yes, the unknowns seem to stay in solution for re-x and gets poured off.
The evap test is where things get weird. The unknowns easily salt out with weak acid, but otherwise evaporate off along with the naphtha. If they were lighter chemicals, this would make sense, but with molecular weights in the 800s, this is a bit confusing.