Structural Characterization of Naturally Occurring Oligosaccharides by Matrix-Assisted Molecular Secondary Ion Mass Spectrometry

Normally, a glycerol matrix is essential in sputtered ion mass spectrometry such as fast atom bombardment (FAB) and molecular secondary ion mass spectrometry (SIMS) [1]. Recently, we have successfully applied an amine matrix, diethanolamine (DEA) and triethanolamine (TEA), instead of glycerol for the determination of molecular weight of neutral oligosaccharides by molecular SIMS [2]. When DEA was used, a stable molecular adduct ion species, the [M+DEAH]+ ion, was formed as the sole ion derived from a neutral saccharide molecule and no fragment ions were detected. Moreover, the [M+DEAH]+ ion scarcely decomposed even under collisionally activated dissociation (CAD) conditions.