Premium
Chemical ionization mass spectrometry of derivatives of L ‐dopa and L ‐tryptophan and their detection in tumour samples
Author(s) -
Duarte M. F. N.,
Hutchinson D. W.,
Jennings K. R.
Publication year - 1985
Publication title -
organic mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 0030-493X
DOI - 10.1002/oms.1210200710
Subject(s) - derivatization , chemistry , mass spectrometry , reagent , fragmentation (computing) , tryptophan , chromatography , chemical ionization , mass spectrum , methylamine , ion , ionization , amino acid , organic chemistry , biochemistry , computer science , operating system
Conditions have been established for the detection by chemical ionization mass spectrometry (CIMS) of compounds related to L ‐dopa (3‐hydroxy‐ L ‐tyrosine) and L ‐tryptophan without derivatization. The least fragmentation of the parent ion occurs in positive ion CIMS when methylamine is used as reagent gas. The compounds can also be detected by negative ion CIMS using carbon tetrachloride as reagent gas. While the total ion current in the latter technique is lower than that obtained with positive ion CIMS, the background noise in the mass spectra of samples obtained from natural sources is greatly reduced. CIMS has been used to show the presence of aromatic amino acids in acid extracts of samples of two different classes of tumour without sample derivatization.