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Characterization of diastereomeric and enantiomeric ephedrines by gas chromatography combined with electron impact mass spectrometry and isobutane chemical ionization mass spectrometry
Author(s) -
Gilbert Mary T.,
Brooks Charles J. W.
Publication year - 1977
Publication title -
biomedical mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 0306-042X
DOI - 10.1002/bms.1200040407
Subject(s) - isobutane , ephedrine , chemistry , diastereomer , electron ionization , mass spectrometry , mass spectrum , trimethylsilyl , chemical ionization , gas chromatography , chromatography , gas chromatography–mass spectrometry , enantiomer , analytical chemistry (journal) , ion , ionization , organic chemistry , catalysis , neuroscience , biology
The diastereomeric hydroxyamines, ephedrine and ψ‐ephedrine, were well differentiated by gas chromatography of their N ‐acetyl O ‐trimethylsilyl derivatives. For the analytical separation of enantiomers, conversion into N ‐( R )‐ψ‐phenylbutyryl O ‐trimethylsilyl derivatives was effective in the cases of ephedrine, ψ‐ephedrine and nor‐ψ‐ephedrine (but not that of nor‐ephedrine, on the two stationary phases used). Electron impact mass spectra showed structurally diagnostic fragmentations, but the two diastereomeric amides from each pair of enantiomers yielded generally similar spectra. Molecular ions were of low abundance, but under chemical ionization conditions (isobutane) abundant protonated molecular ions were produced.