title: 5-Methoxysalicylic acid and spermine: a new matrix for the matrix-assisted laser desorption/ionization mass spectrometry analysis of oligonucleotides.
abstract: 5-Methoxysalicylic acid (MSA) is demonstrated to be a useful matrix for matrix-assisted laser desorption/ionization time-of-flight (TOF) mass spectrometry of oligonucleotides, when desorption/ionization without fragmentation is desired. When MSA is combined with the additive spermine, the need for desalting is reduced. The MSA/spermine matrix yields linear TOF mass spectra with improved resolution, less fragmentation, and less intense alkali ion adduct peaks than those spectra obtained using 3-hydroxypicolinic acid and 6-aza-2-thiothymine with spermine or diammonium hydrogen citrate as additives. Instrumental conditions are discussed to improve the spectral resolution, specifically the use of longer delay times in the delayed-extraction ion source.
authors.affiliation: Department of Chemistry, Michigan State University, East Lansing 48824-1322, USA.
authors.forename: A M
authors.initials: AM
authors.lastname: Distler
authors.forename: J
authors.initials: J
authors.lastname: Allison
mesh_terms: D019343:Citric Acid / Q000031:analogs & derivatives / Q000737:chemistry*; D062425:Hydroxybenzoate Ethers; D007202:Indicators and Reagents; D009841:Oligonucleotides / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D012459:Salicylates / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013056:Spectrophotometry, Ultraviolet; D013096:Spermine / Q000737:chemistry*
chemical_list: D062425:Hydroxybenzoate Ethers; D007202:Indicators and Reagents; D009841:Oligonucleotides; D000644:Quaternary Ammonium Compounds; D012459:Salicylates; C033304:5-methoxysalicylic acid; D019343:Citric Acid; D013096:Spermine; C426729:diammonium hydrogen citrate