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Molecular formula analysis of fragment ions by isotope‐selective collision‐induced dissociation tandem mass spectrometry of pharmacologically active compounds
Author(s) -
Bianco Giuliana,
Buchicchio Alessandro,
Lelario Filomena,
Cataldi Tommaso R.I.
Publication year - 2014
Publication title -
journal of mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 1076-5174
DOI - 10.1002/jms.3468
Subject(s) - chemistry , collision induced dissociation , tandem mass spectrometry , mass spectrometry , tandem , dissociation (chemistry) , ion , isotope , fast atom bombardment , chromatography , computational chemistry , organic chemistry , nuclear physics , materials science , physics , composite material
The purpose of this work is to explore the mass fragment characterization of commonly used drugs through a novel approach, which involves isotope‐selective tandem mass spectrometry (MS/MS). Collision‐induced dissociation (CID) was performed with a low‐resolution linear ion trap mass spectrometer in positive electrospray ionization. Three pharmacologically active ingredients, i.e. omeprazole, meloxicam and brinzolamide, selected as model compounds in their own formulation, were investigated as a sodiated adduct [C 17 H 19 N 3 O 3 S + Na] + (omeprazole) and as protonated adducts, [C 14 H 13 N 3 O 4 S 2 + H] + and [C 12 H 21 N 3 O 5 S 3 + H] + , meloxicam and brinzolamide, respectively. Selecting a narrow window of ±0.5 m/z units, precursor ion fragmentation by CID‐MS/MS of isotopologues A + 0, A + 1 and A + 2 was found very useful to confirm the chemical formula of product ions, thus aiding the establishment of characteristic fragmentation pathways of all three examined compounds. The correctness of putative molecular formula of product ions was easily demonstrated by exploiting the isotope peak abundance ratios (i.e. I F+0 /I F+1 and I F+0 /I F+2 ) as simple constraints in low‐resolution MS instrumentations. Copyright © 2014 John Wiley & Sons, Ltd.