Gas chromatographic/mass spectrometric assay for profiling the enantiomers of 3,4-methylenedioxymethamphetamine and its chiral metabolites using positive chemical ionization ion trap mass spectrometry.
A qualitative GC/MS profile was obtained and its mass spectrometric features characterized for the analysis of the enantiomers of (RS)-3,4-methylenedioxymethamphetamine (MDMA) and its metabolites (RS)-3,4-methylenedioxyamphetamine (MDA), (RS)-4-hydroxy-3-methoxymethamphetamine (HMMA) and (RS)-4-hydroxy-3-methoxyamphetamine (HMA). A chiral derivatization method was selected to obtain the diastereomers required for the separation of the respective enantiomers with a non-chiral GC stationary phase. The selected derivatization consisted of a reaction with N-heptafluorobutyryl-(S)-prolyl chloride combined with a consecutive reaction with N-methyl-N-trimethylsilyltrifluoroacetamide, resulting in N-[heptafluorobutyryl-(S)-prolyl]-O-trimethylsilyl derivatives. Detection was carried out with electron ionization and positive chemical ionization (PCI) ion trap mass spectrometry. Mass spectra of the derivatives of reference standards of the compounds of interest obtained with PCI demonstrated that this method simultaneously induces proton and charge-transfer reactions in the ion trap. The advantage is that high mass information is provided while some fragmentation remains to elucidate structural details. Subsequently, in three urine samples obtained from different and unrelated MDMA intoxications, the enantiomers of MDMA and MDA were identified. In some urine samples also HMMA and/or HMA were found. In addition to these compounds, an unexpected compound and/or additional chiral metabolite, N-hydroxy-(RS)-3,4-methylenedioxyamphetamine, was identified in two out of three urine samples. Preliminary results also indicated an enantioselective metabolism in the N-demethylation pathway for MDMA in humans.
de Boer
D
D
Department of Human Toxicology, Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, The Netherlands. D.de Boer@far.ruu.nl
Tan
L P
LP
Gorter
P
P
van de Wal
R M
RM
Kettenes-van den Bosch
J J
JJ
de Bruijn
E A
EA
Maes
R A
RA
D001711:Biotransformation; D008401:Gas Chromatography-Mass Spectrometry; D006213:Hallucinogens / Q000493:pharmacokinetics* / Q000652:urine*; D006801:Humans; D007536:Isomerism; D018817:N-Methyl-3,4-methylenedioxyamphetamine / Q000493:pharmacokinetics* / Q000652:urine*; D012015:Reference Standards
D006213:Hallucinogens; D018817:N-Methyl-3,4-methylenedioxyamphetamine