In-source fragmentation and analysis of polysaccharides by capillary electrophoresis/mass spectrometry
Article first published online: 18 APR 2005
Copyright © 2005 Crown in the right of Canada. Published by John Wiley & Sons, Ltd.
Rapid Communications in Mass Spectrometry
Volume 19, Issue 10, pages 1305–1314, 30 May 2005
How to Cite
Li, J., Wang, Z. and Altman, E. (2005), In-source fragmentation and analysis of polysaccharides by capillary electrophoresis/mass spectrometry. Rapid Commun. Mass Spectrom., 19: 1305–1314. doi: 10.1002/rcm.1927
- Issue published online: 18 APR 2005
- Article first published online: 18 APR 2005
- Manuscript Accepted: 15 MAR 2005
- Manuscript Revised: 14 MAR 2005
- Manuscript Received: 15 JAN 2005
- National Research Council's Genomics and Health Initiative
In order to develop a robust and easy-to-use technique for characterization of bacterial polysaccharides, a pseudo-hydrolysis strategy was investigated. Based on in-source collision-induced dissociation, polysaccharide molecular ions were fragmented within the orifice-skimmer region of an electrospray ionization (ESI) mass spectrometer. The fragment ions thus generated were then analyzed similarly to the conventional ESI mass spectrometry approach. MS/MS scanning was applied to obtain product-ion spectra of the primary fragments for sequencing. To further improve the sensitivity and separation of polysaccharides from other components in the samples, a pressure-assisted capillary electrophoresis/mass spectrometry (CE/MS) system was employed. Using bacterial polysaccharides as model compounds, the mass spectra obtained for polysaccharide repeating units generated through chemical hydrolysis and in-source fragmentation were directly compared, both in positive and negative ion modes. With the additional separation of impurities provided by CE, the success of this technique has been demonstrated for structural analysis of O-chain polysaccharides (O-PS) and capsular polysaccharides (CPS). In-source fragmentation was applied to promote the formation of structurally relevant repeating units of heterogeneous CPS that would remain undetected using conventional ESI conditions. This approach was proven to be particularly useful for probing the subtle structural differences in monosaccharide composition and functionalities arising across bacterial serotypes. Copyright © 2005 Crown in the right of Canada. Published by John Wiley & Sons, Ltd.