Challenges in the Analysis of Gangliosides by LC-MS.

Gangliosides are a family of conjugates consisting of a polar sialoglycan head group and a hydrophobic ceramide tail. Gangliosides are of high abundance in neuronal tissues and are involved in numerous biological processes, such as cell-cell recognition, adhesion, and signal transduction. Alteration of the ganglioside profile is associated with various neurodegenerative diseases and there is indication that gangliosides are involved in the pathogenesis of Parkinson's and Huntington's disease. The development of refined methods for the analysis of gangliosides by high-performance liquid chromatography coupled to mass spectrometry (HPLC-MS) has supported research with qualitative and quantitative data. However, the amphiphilic character of gangliosides renders their separation and mass spectrometric analysis challenging. In this article, the strengths of hydrophilic interaction liquid chromatography (HILIC) for baseline separation of gangliosides, including two structural isomers, and their structural characterization by tandem mass spectrometry are demonstrated. The importance of ion source parameter optimization is highlighted to prevent misleading ganglioside transformation due to in-source dissociation.