Premium
Analysis of perfluoroalkyl anion fragmentation pathways for perfluoroalkyl carboxylates and sulfonates during liquid chromatography/tandem mass spectrometry: evidence for fluorine migration prior to secondary and tertiary fragmentation
Author(s) -
Arsenault Gilles,
McAlees Alan,
McCrindle Robert,
Riddell Nicole
Publication year - 2007
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.3274
Subject(s) - chemistry , fragmentation (computing) , tandem mass spectrometry , ion , carbanion , mass spectrometry , electrospray , medicinal chemistry , fluorine , liquid chromatography–mass spectrometry , stereochemistry , chromatography , organic chemistry , computer science , operating system
It is known that under liquid chromatography/electrospray tandem mass spectrometry (LC/ES‐MS/MS) conditions, the perfluorocarboxylate anion [R F CO 2 ] − first loses CO 2 to give a perfluoroalkyl anion R F − , [(MH)CO 2 ] − , which can subsequently fragment to give inter alia lower mass carbanions. It has been suggested in a previous study that such secondary fragmentation involves cleavage of C n F 2n segments. Our study of the LC/ES‐MS/MS of a series of 13 C‐labeled perfluoroalkyl carboxylic acids (PFCAs) indicates that fragmentation of the R F −anion does not involve simple 'unzipping' of a primary perfluoroalkyl anion of the type F 3 C(CF 2 ) x CF 2 − . For example, we have discovered that the secondary transition for the mass‐labeled PFOA, perfluoro‐1,2,3,4‐ 13 C 4 ‐octanoic acid (MPFOA), gives two signals of equal intensity at m/z 169 and 172. We propose a mechanism of fragmentation that involves rapid fluorine shifts, after the initial decarboxylation, which generate a series of new anions prior to secondary and tertiary fragmentation. Copyright © 2007 John Wiley & Sons, Ltd.