GC/MS of methylone

[Coolio]

J Chromatogr Sci. 2006 Mar;44(3):155-61.

Chromatographic and mass spectral studies on methoxymethcathinones related to 3,4-methylenedioxymethamphetamine.

Awad T, Clark CR, DeRuiter J.

Department of Pharmacal Sciences, School of Pharmacy, Auburn University, Auburn, AL 36849, USA.

The methoxymethcathinones are uniquely regioisomeric with the controlled drug substance 3,4-methylenedioxymethamphetamine (3,4-MDMA) or Ecstacy. The various isomeric forms of the methoxymethcathinones have mass spectra essentially equivalent to 3,4-MDMA. They all have a molecular weight of 193 and major fragment ions in their electron ionization mass spectra at m/z 58 and 135/136. Differentiation by mass spectrometry was only possible after formation of the perfluoroacyl derivatives, pentafluoropropionylamides (PFPA), and heptafluorobutrylamides (HFBA). Gas chromatographic separation on nonpolar stationary phases successfully resolved the three methcathinones from 2,3- and 3,4-MDMA as the PFPA and HFBA derivatives.

Looks like methylone shows up as MDMA on mass spectrometry test results... and I can't determine from this abstract, but also GC is the same? Does this mean ecstasydata.org etc. results as well as submissions to DEA laboratories that show MDMA in pills might actually be methylone?

 

[J. Alfred Prufrock]

Correct me if I'm mistaken, but doesn't methylone have a molecular weight of 207 while MDMA is 193? So no, there shouldn't be false positives on GC/MS analysis.

Also, while most N-methyl amphetamines will have a base (most intense) peak of 58 where the terminal amine fragments, you'll be left with 149 and 121 for methylone.....not 58 and 135/136 as indicated in the abstract.

Compare the rationalization below with the mass spectrum on Erowid...

 

[Coolio]

I wasn't paying enough attention. Methylone isn't one of the "methoxymethcathinones", it's a methylenedioxymethcathinone. I imagine they were testing 4-methoxymethcathinone or something?

I'm just trying to figure out if someone here can interpret that study for me, because it makes little sense to me.

 

[J. Alfred Prufrock]

You'll have to come up with isomers of methoxymethcathinones with a MW of 193 by yourself.

It shouldn't be hard. Methcathinone itself has a MW of 163. MDMA and these "methoxymethcathinones" both have a MW of 193.

193-163 = 30

The methoxy group is -OCH3 which has a weight of (16+12+3x1) = 31

If you substitute a hydrogen on the ring with a methoxy group, the net difference is (+31) and (-1) = 30, thus they are referring to mono-methyoxy substitution on the ring.

You would have 3 possible isomers....2-methyoxymethcathinone, 3-methyoxymethcathinone, and 4-methyoxymethcathinone.

These will spit the 58 amine fragment indicative of methamphetamine leaving 193-58 = 135 as the ring containing fragment.

When MDMA fragments, it would also have the 193 to 58 & 135 pattern.

The derivatization probably imparts some additional selectivity on the GC column allowing separation, but the abstract seems to imply the mass spectra are now distinct.

 

[djfriendly]

I can't determine from this abstract, but also GC is the same?

Nope. The abstract states:

Gas chromatographic separation on nonpolar stationary phases successfully resolved the three methcathinones from 2,3- and 3,4-MDMA

which means that GC could distinguish MDMA from whichever cathinones they tested.

 

[hugo24]

Has anyone tasted 4-Methoximethcathinon?I guess its a winner (I love its mother PMMA).

 

[Coolio]

djfriendly, the rest of that sentence reads "as the PFPA and HFBA derivatives." Are they talking about perfluoroacyl derivatives of MDMA, or of methcathinones?