A general approach to the screening and confirmation of tryptamines and phenethylamines by mass spectral fragmentation.
Bo-hong Chen, Ju-tsung Liu, Wen-xiong Chen, Hung-ming Chen, Cheng-huang Lin
Talanta January 15, 2008 Peer reviewed DOI: 10.1016/j.talanta.2007.06.012 via PubMed
Summary
The study describes the fragmentation patterns of tryptamines and phenethylamines using various mass spectrometry techniques. It finds that while parent ions are difficult to obtain via GC/MS, protonated molecular ions are clearly observable with ESI/MS and MALDI/TOFMS. The major fragmentation processes differ between ESI and MALDI, with alpha-cleavage being predominant in ESI and beta-cleavage in MALDI. Fragmentation efficiency is linked to the alkylation degree of the side chain nitrogen.
Study at a glance
| Sample size | 13 |
|---|---|
| Population | standard compounds including various tryptamines and phenethylamines |
| Key finding | Protonated molecular ions of tryptamines and phenethylamines are clearly observed using ESI/MS and MALDI/TOFMS, with distinct fragmentation patterns for each method. |
Abstract
Certain characteristic fragmentations of tryptamines (indoleethylamine) and phenethylamines are described. Based on the GC-EI/MS, LC-ESI/MS and MALDI/TOFMS, the mass fragmentations of 13 standard compounds, including alpha-methyltryptamine (AMT), N,N-dimethyltryptamine (DMT), 5-methoxy-alpha-methyltryptamine (5-MeO-AMT), N,N-diethyltryptamine (DET), N,N-dipropyltryptamine (DPT), N,N-dibutyltryptamine (DBT), N,N-diisopropyltryptamine (DIPT), 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT), 5-methoxy-N,N-diisopropyltryptamine (5-MeO-DIPT), methamphetamine (MAMP), 3,4-methylenedioxyamphetamine (3,4-MDA), 3,4-methylenedioxymethamphetamine (3,4-MDMA) and 2-methylamino-1-(3,4-methylenedioxyphenyl)butane (MBDB), were compared. As a result, the parent ions of these analytes were hard to be obtained by GC/MS whereas the protonated molecular ions can be observed clearly by means of ESI/MS and MALDI/TOFMS. Furthermore, two major characteristic fragmentations, namely and alpha-cleavage ([M+H](+)-->[3-vinylindole](+)) and beta-cleavage ([M+H](+)-->[CH(2)N(+)R(N1)R(N2)]), are produced when the ESI and MALDI modes are used, respectively. In the case of ESI/MS, the fragment obtained from alpha-cleavage is the major process. In contrast to this, in the case of MALDI/TOFMS, the major fragment is produced via beta-cleavage. The ionization efficiency and fragments formed from either alpha- or beta-cleavages are closely related to the degree of alkylation of the side chain nitrogen in both cases.