title: Dual polarity accurate mass calibration for electrospray ionization and matrix-assisted laser desorption/ionization mass spectrometry using maltooligosaccharides.
abstract: In view of the fact that memory effects associated with instrument calibration hinder the use of many mass-to-charge (m/z) ratios and tuning standards, identification of robust, comprehensive, inexpensive, and memory-free calibration standards is of particular interest to the mass spectrometry community. Glucose and its isomers are known to have a residue mass of 162.05282Da; therefore, both linear and branched forms of polyhexose oligosaccharides possess well-defined masses, making them ideal candidates for mass calibration. Using a wide range of maltooligosaccharides (MOSs) derived from commercially available beers, ions with m/z ratios from approximately 500 to 2500Da or more have been observed using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) and time-of-flight mass spectrometry (TOF-MS). The MOS mixtures were further characterized using infrared multiphoton dissociation (IRMPD) and nano-liquid chromatography/mass spectrometry (nano-LC/MS). In addition to providing well-defined series of positive and negative calibrant ions using either electrospray ionization (ESI) or matrix-assisted laser desorption/ionization (MALDI), the MOSs are not encumbered by memory effects and, thus, are well-suited mass calibration and instrument tuning standards for carbohydrate analysis.
authors.affiliation: Department of Chemistry, University of California, Davis, Davis, CA 95616, USA.
authors.forename: Brian H
authors.initials: BH
authors.lastname: Clowers
authors.forename: Eric D
authors.initials: ED
authors.lastname: Dodds
authors.forename: Richard R
authors.initials: RR
authors.lastname: Seipert
authors.forename: Carlito B
authors.initials: CB
authors.lastname: Lebrilla
mesh_terms: D002138:Calibration; D002241:Carbohydrates / Q000032:analysis* / Q000737:chemistry; D002853:Chromatography, Liquid; D005583:Fourier Analysis; D007259:Infrared Rays; D008970:Molecular Weight; D009844:Oligosaccharides / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods / Q000592:standards*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods / Q000592:standards*
chemical_list: D002241:Carbohydrates; D009844:Oligosaccharides; C021705:maltooligosaccharides