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Isomer separation and analysis of amphiphilic polysialogangliosides using reversed‐phase liquid chromatography‐mass spectrometry
Author(s) -
Park Jun Young,
Shrestha Sarmila Amatya,
Cha Sangwon
Publication year - 2021
Publication title -
journal of separation science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.72
H-Index - 102
eISSN - 1615-9314
pISSN - 1615-9306
DOI - 10.1002/jssc.202001248
Subject(s) - chemistry , chromatography , hydrophilic interaction chromatography , mass spectrometry , electrospray ionization , reversed phase chromatography , high performance liquid chromatography , acetonitrile , electrospray , structural isomer , liquid chromatography–mass spectrometry , selectivity , ammonium bicarbonate , organic chemistry , catalysis , raw material
Gangliosides are amphiphilic, acidic glycosphingolipids possessing one or more sialic acid residues and several isobaric structural isomers with different abundances and bioactivities. Therefore, the distinction between these isomers is crucial for their proper profiling. Although liquid chromatography–mass spectrometry has been successfully employed for this purpose, the distinction process can still be improved, particularly regarding liquid chromatography. Recently, a reversed‐phase liquid chromatography method that could separate disialoganglioside isomers was reported; however, the distinction of trisialoganglioside isomers using reversed‐phase liquid chromatography has not been demonstrated. Here, we investigated the practicality of a reversed‐phase liquid chromatography with an octadecylsilane column for separating polysialoganglioside isomers and successfully achieved the isomer separation of disialogangliosides and trisialogangliosides for the first time. We also confirmed several crucial factors in the mobile‐phase composition, which affect the differential retention and mass spectral response of the isomers. First, an organic modifier, acetonitrile, exhibited superior selectivity against polysialogangliosides over methanol. Second, ammonium bicarbonate was the best ammonium salt additive among those tested, in terms of the separation efficiency and mass spectral response. Third, as the ammonium salt concentration increased, the negative electrospray ionization response was extensively suppressed, and the retention of gangliosides increased.