RECOGNITION OF QUATERNARY AMMONIUM-COMPOUNDS USING MASS-SPECTROMETRY

被引:8
作者
FISHER, DL
MOSELEY, MA
MULLIS, JO
NORWOOD, DL
机构
[1] Glaxo Research Institute, North Carolina, 5 Moore Drive, PO Box 13960, Research Triangle Park
[2] Department of Medicinal Chemistry, University of Washington, Seattle, Washington
关键词
D O I
10.1002/rcm.1290080113
中图分类号
Q5 [生物化学];
学科分类号
071010 ; 081704 ;
摘要
Liquid secondary-ion mass spectrometry (LSIMS) experiments were performed on a series of model quaternary ammonium chlorides [M(Q)+Cl-] in order to develop a strategy, via an understanding of cluster-ion formation, for recognition of quarternary ammonium structures. Model structures contained a single quaternary site and various other structural features (for example, conjugated quaternary systems and carboxylic acid groups), using amine hydrochlorides as controls. Cluster ions were examined with both positive- and negative-ion LSIMS, using a range of matrix modifiers. Precursor scans, or 'molecular weight confirmation scans', of M(Q)+ (the charged molecular ion of quaternary ammonium compounds) and [M+H]+ ions were used to assist in the observation of cluster ions and to unambiguously demonstrate precursor/product relationships. Positive-ion experiments typically showed dimeric clusters of [2M(Q) + A]+ (A = anion) and [2M(Q) - H]+ ions, while negative-ion experiments produced [M(Q) + 2A]- ions. Observation of these cluster ions coupled with the lack of an [M-H]- ion are a distinguishing feature of quaternary amines. Additional cluster ions were targeted for distinguishing between protonated amines and quaternary amonium compounds containing a carboxylic acid group. A strategy for recognizing and distinguishing quaternary ammonium structures using LSIMS is proposed, and some initial experiments with thermospray and electrospray are discussed.
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页码:65 / 70
页数:6
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