Optimization of Electrospray Ionization (ESI)

Return to MS Analysis of GAGs

Due to the acidity and lability of sulfate groups present on GAGs, ESI is the preferred technique because it can result in little or no in-source fragmentation when properly tuned (1). Optimization of the ESI tuning parameters is crucial for the accurate MS analysis of sulfated GAGs. Highly sulfated heparin hexasaccharide standards with defined structure can be used to optimize the ESI tuning parameters in various mass spectrometers. Extent and position of sulfation can lead to varying degrees of lability for every oligosaccharide. The lability of the sulfate groups increases as the size of the heparin oligosaccharide increases. Successful tuning parameters are more easily achieved using a highly sulfated hexasaccharide standard as compared to a disaccharide standard.


  1. Kim, Y. S et al. (1998) Glycobiology 8(9):869-877. PMID: 9675219