Sorry for being this insistent but I found this thread which suggests that Mephedrone could undergo degradation like Methylone and Methcathione:
https://drugs-forum.com/threads/the-stability-of-the-mephedrone-molecule.102771/
I don't have enough chemistry knowledge to reliable review the points...
This paper suggest that Mephedrone as well as other Cathinones are unstable in certain solutions (MeOH, ACN).
https://www.frontiersin.org/articles/10.3389/fchem.2020.597726/full
Does anybody have any solid information about the long term stability of Mephedrone and other Cathinones outside of...
What exactly does 40% stand for?
I believe 40% wt./wt. should be 664g MeNH2 in 1L of H2O. (997g/mol (H2O) / 60% * 40%)
This would mean that 1 liter would contain ~21 mols of methylamine. (664g / 31.1g/mol)
The following listing shows that it only should have 12 mol/l...