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A study of gas‐phase cationization in matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry
Author(s) -
Erb William J.,
Hanton Scott D.,
Owens Kevin G.
Publication year - 2006
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.2568
Subject(s) - chemistry , mass spectrometry , reagent , desorption , lithium hydroxide , analyte , analytical chemistry (journal) , ethylene glycol , soft laser desorption , matrix assisted laser desorption/ionization , matrix assisted laser desorption electrospray ionization , matrix (chemical analysis) , hydroxide , sample preparation , phase (matter) , ionization , mass spectrum , ion , ion exchange , inorganic chemistry , chromatography , organic chemistry , adsorption
A specially constructed split sample probe was used to unequivocally demonstrate that gas‐phase cationization occurs within the desorption plume during a matrix‐assisted laser desorption/ionization experiment. Two separate samples were prepared for analysis: on side A, a mixture of poly(ethylene glycol) (PEG) 1500 analyte and 2,5‐dihydroxybenzoic acid (DHB) matrix, and on side B a mixture of DHB matrix and lithium hydroxide (LiOH), the cationization reagent. Analysis of the data showed that when the ionization laser was focused on the split (so that both sides were illuminated), Li + ‐cationized PEG peaks were observed. Since the PEG analyte did not come into contact with Li + in either the solution or solid phase, the only possibility for the observed cationization was a reaction in the gas phase. Due to the difficulty in completely removing the adventitious cations (Na + and K + ) present in DHB and on sample surfaces, gas‐phase cationization could not be demonstrated to be either the only or most important mechanism operating in the MALDI experiment. Copyright © 2006 John Wiley & Sons, Ltd.