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The Use of a Co‐matrix for Improved Analysis of Oligonucleotides by Matrix‐assisted Laser Desorption/Ionization Time‐of‐flight Mass Spectrometry
Author(s) -
Simmons Tracey A.,
Limbach Patrick A.
Publication year - 1997
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/(sici)1097-0231(199704)11:6<567::aid-rcm917>3.0.co;2-o
Subject(s) - chemistry , mass spectrometry , sample preparation in mass spectrometry , matrix (chemical analysis) , oligonucleotide , desorption , electrospray ionization , analytical chemistry (journal) , matrix assisted laser desorption/ionization , chromatography , organic chemistry , dna , biochemistry , adsorption
Cation adduction to oligonucleotides and nucleic acids during mass spectrometric analysis is a recurrent problem. We have found that the use of organic base solutions of high gas‐phase proton affinity, as used previously in electrospray ionization mass spectrometry, can significantly reduce the cation adduction problem during matrix‐assisted laser desorption/ionization (MALDI) mass spectrometry. A comparison of the utility of adding imidazole or triethylamine as a co‐matrix versus the standard addition of cation exchange resin beads was made. The co‐matrices studied were found to be more effective than the cation exchange resin beads at reducing cation adducts from samples containing a high level of salt. The use of co‐matrices also appears to improve the gas‐phase stability of larger oligonucleotides. MALDI‐time‐of‐flight analysis of a binary mixture of oligoribonucleotide 27‐mers with a co‐matrix exhibited less metastable decomposition than the same analysis using cation exchange resin beads. The use of co‐matrices may be a viable strategy for the mass spectrometric characterization of larger oligonucleotides obtained from media containing a high salt content such as polymerase chain reaction products. © 1997 John Wiley & Sons, Ltd.