RECENT PROGRESS IN HIGH-PERFORMANCE ANION-EXCHANGE CHROMATOGRAPHY IONSPRAY MASS-SPECTROMETRY FOR MOLECULAR-MASS DETERMINATION AND CHARACTERIZATION OF CARBOHYDRATES USING STATIC AND SCANNING ARRAY DETECTION

Position-and time-resolved ion counting (PATRIC) array detection with a magnetic sector mass spectrometer equipped with an ionspray interfac e in the on-line coupling of high-performance anion-exchange chromatog raphy (HPAEC) with mass spectrometry (MS) is described. PATRIC array d etection is used in both the static and scanning mode for molecular ma ss determination and structure characterization caused by nozzle/skimm er-induced fragmentation in the ionspray interface. The virtual mass r ange is extended to over 7000 Da by the presence of triply and quadrup ly sodiated molecules in an enzyme digest of an exocellular polysaccha ride (EPS) of Lactococcus lactis and quadruply sodiated molecules of b eta-1,4-xglose oligomers. After optimization of the HPAEC/MS system, m olecular mass information could be obtained down to similar to 700 pg per injection for each alpha-1,4-glucose oligomer up to a degree of po lymerization of 7 using PATRIC array detection in the static mode. Str ucture information was obtained for alpha-1,4 glucose oligomers, galac turonic acid oligomers and an EPS digest using PATRIC array detection in the scanning mode. (C) 1998 John Wiley & Sons, Ltd.