CHARACTERIZATION OF CARBOHYDRATES USING A COMBINATION OF DERIVATIZATION, HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY AND MASS-SPECTROMETRY

A combination of derivatization methods, chromatographic techniques an d mass spectrometric ionization modes have been explored for the chara cterization of small sugars and medium-size oligosaccharides. Derivati zation using 1-phenyl-3-methyl-5-pyrazolone (PMP) was preferred over p yridylamination (PA) owing to the simplicity of the reaction method, a nd also to enhanced ionization efficiency of the PMP derivatives relat ive to aminopyridyl sugars. The good quality and ease of separation of PMP derivatives by high-performance liquid chromatography were also a dvantages of using PMP derivatization rather than pyridylamination. PM P- and PA-monosaccharides produced abundant ions by either fast atom b ombardment (FAB), electrospray ionization (ESI) or matrix-assisted las er desorption/ionization (MALDI). The PA and PMP derivatives of lactos e, fucosyllactose and sialyllactose yielded FAB spectra with low SIN r atios, whereas ESI and MALDI produced better spectra with a hundredth of the material used for FAB. In general, PMP derivatives of these di- and trisaccharides gave rise to stronger signals than PA analogs. For oligosaccharides;containing more than three sugar rings, only PMP was used for derivatization, FAB was dropped and only ESI and MALDI were utilized. (C) 1998 Elsevier Science B.V. All rights reserved.