Separation of glycosidic catiomers by TWIM‐MS using CO₂ as a drift gas

Abstract

Traveling wave ion mobility mass spectrometry (TWIM-MS) is shown to be able to separate and characterize several isomeric forms of diterpene glycosides stevioside (Stv) and rebaudioside A (RebA) that are cationized by Na(+) and K(+) at different sites. Determination and characterization of these coexisting isomeric species, herein termed catiomers, arising from cationization at different and highly competitive coordinating sites, is particularly challenging for glycosides. To achieve this goal, the advantage of using CO2 as a more massive and polarizable drift gas, over N2, was demonstrated. Post-TWIM-MS/MS experiments were used to confirm the separation. Optimization of the possible geometries and cross-sectional calculations for mobility peak assignments were also performed.

Use of ion mobility mass spectrometry to enhance cumulative analytical specificity and separation to profile 6‐C/8‐C‐glycosylflavone critical isomer pairs and known–unknowns in medicinal plants

“…The strategy employed herein, is to utilise CCS searchable data bases which was initially illustrated by Goscinny and coworkers and McCullagh and coworkers for pesticides and veterinary drugs analysis . The use of CCS data bases continues to increase and have been developed across multiple areas of research, including mycotoxins, metabolism, steroids, steviosides and direct analysis of isomers …”

Investigations into the performance of travelling wave enabled conventional and cyclic ion mobility systems to characterise protomers of fluoroquinolone antibiotic residues

“…CCS searchable data bases have been created across multiple areas of research including natural product screening/metabolism, veterinary drugs, metabolomics, lipids, mycotoxins, steroids and steviosides . IM separations of chromatographically coeluting isomers of metabolites, C 6/ C 8 glycosidic flavonoids and isomer direct analysis have also been performed …”

“…[18][19][20][21][22][23][24][25][26][27] IM separations of chromatographically coeluting isomers of metabolites, C6/C8 glycosidic flavonoids and isomer direct analysis have also been performed. [28][29][30][31][32] The use of IM separation for small molecule analysis has increased across many application areas. An approach in which it is possible to identify FLQ protomers (gas-phase isomers differentiated only by their protonation site) using accurate mass measurement in conjunction with CCS measurement, without relying on characteristic fragmentation ratios, could be beneficial, for example, at low concentrations, where product ions may be weak or unobserved; IM separation could also provide a further confirmatory, differentiating metric for protomers (where fragmentation has been observed).…”

Ion mobility mass spectrometry of saponin ions

“…8,29,[32][33][34] Recently, the capabilities of Ion Mobility Mass Spectrometry (IMMS) to define the primary as well as secondary structures of (bio) molecules have been abundantly tested and promising results have already been reported in the literature on proteins, 35 synthetic polymers 36 and small molecules. [37][38][39] Moreover, the use of IMMS for the study of secondary metabolites, such as flavonoids, 40,41 isomeric flavanols, 42 stevioside and rebaudioside glycosides 43 has started to be documented. In a recent publication, we described a global MS-based methodology for saponin extract analysis that associates matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF), HRMS, liquid chromatography (LC)/MS, CID and IMMS.…”