Polyanionic oligosaccharides such as dermatan sulfate (DS) and chondroitin sulfate (CS) exhibit poor ionization efficiencies and tend to undergo thermal fragmentation through the loss of SO3 under conventional ultraviolet matrix-assisted laser desorption/ionization (UV-MALDI) conditions. A new ionic liquid matrix (ILM), a guanidinium salt of α-cyano-4-hydroxycinnamic acid, facilitates direct UV-MALDI mass spectrometric (MS) analysis of underivatized DS and CS oligosaccharides up to a decasaccharide in their common form as sodium salts. The resulting mass spectra show very low extent of fragmentation through an SO3 loss. The new ILM is suitable for MALDI-MS analysis of mixtures containing oligosaccharides with different numbers of sulfo groups.
All Science Journal Classification (ASJC) codes
- Analytical Chemistry