A comparative study on structural elucidation of sialyl oligosaccharides by mass spectrometry with fast atom bombardment, electrospray ionization, and matrix assisted laser desorption/ionization

To establish a new protocol for sensitive detection and structural characte rization of sialyl oligosaccharides, their sensitivities and structural inf ormation from mass spectrometry and tandem mass spectrometry with FAB-, ESI -, and MALDI were evaluated in detail. Among these ionization methods, FAB- MS and FAB-MS/MS gave reproducible and predictable spectra carrying informa tion on sequence and branching of sialyl oligosaccharides after derivatizat ion with 2-aminopyridine (PA). With both positive and negative ion modes, t heir structural elucidation promises to be straightforward, MS/MS spectra b eing measurable at as low as 200 pmol. Thus, this method constitutes a powe rful tool for sensitive detection and structural characterization of limite d quantities of sialyl oligosaccharides by FAB-MS and FAB-MS/MS.