title: Analysis of acidic carbohydrates as their quaternary ammonium or phosphonium salts by matrix-assisted laser desorption/ionization mass spectrometry.
abstract: New two-component systems using quaternary ammonium or phosphonium salts as a co-matrix have been developed for the analysis of acidic carbohydrates by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS). In the analysis of the sodium salt of heparin disaccharide I-S, the combination of 2-amino-5-nitropyridine with tetraphenylphosphonium bromide gave the best result. In the analysis of gangliosides containing the sialic acid moiety, the combination of 2,4,6-trihydroxyacetophenone with dimethyldipalmitylammonium bromide was determined to be the system of choice. Under optimum conditions all acidic carbohydrates gave molecular ions in the form of [M(Q(n))-Q]-, where M(Q(n)) is the molecular mass of a molecule containing n molecules of quaternary ions as salt.
authors.affiliation: Department of Applied Chemistry, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan. maueki@ch.kagu.tus.ac.jp
authors.forename: Masaaki
authors.initials: M
authors.lastname: Ueki
authors.forename: Miyuki
authors.initials: M
authors.lastname: Yamaguchi
mesh_terms: D000143:Acids / Q000737:chemistry*; D002240:Carbohydrate Sequence; D002241:Carbohydrates / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D010710:Phosphates / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D012492:Salts / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D000143:Acids; D002241:Carbohydrates; D010710:Phosphates; D000644:Quaternary Ammonium Compounds; D012492:Salts